# A Survey of Novae in M83

A. W. Shafter Department of Astronomy and Mount Laguna Observatory, San Diego
State University, San Diego, CA 92182, USA  K. Hornoch Astronomical Institute
of the Czech Academy of Sciences, Fričova 298, CZ-251 65 Ondřejov, Czech
Republic  J. Benáček Center for Astronomy and Astrophysics, Technical
University of Berlin, 10623 Berlin, Germany  A. Galád Modra Observatory,
Department of Astronomy, Physics of the Earth, and Meteorology, FMPI UK,
Bratislava SK-84248, Slovakia  J. Janík Department of Theoretical Physics and
Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic  J.
Juryšek Institute of Physics of the Czech Academy of Sciences, Prague, Czech
Republic  Département d’Astronomie, Université de Geneve, Chemin d’Ecogia 16,
CH-1290 Versoix, Switzerland  L. Kotková  Astronomical Institute of the Czech
Academy of Sciences, Fričova 298, CZ-251 65 Ondřejov, Czech Republic  P.
Kurfürst Department of Theoretical Physics and Astrophysics, Masaryk
University, Kotlářská 2, 611 37 Brno, Czech Republic  H. Kučáková Astronomical
Institute of the Czech Academy of Sciences, Fričova 298, CZ-251 65 Ondřejov,
Czech Republic  Research Centre for Theoretical Physics and Astrophysics,
Institute of Physics, Silesian University in Opava, Bezručovo nám. 13,
CZ-74601 Opava, Czech Republic  P. Kušnirák Astronomical Institute of the
Czech Academy of Sciences, Fričova 298, CZ-251 65 Ondřejov, Czech Republic  J.
Liška Central European Institute of Technology - Brno University of Technology
(CEITEC BUT), Purkyňova 656/123, CZ-612 00, Brno, Czech Republic  Variable
Star and Exoplanet Section of the Czech Astronomical Society, Vídeňská 1056,
CZ-142 00, Praha-Libuš  E. Paunzen Department of Theoretical Physics and
Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic  M.
Skarka Astronomical Institute of the Czech Academy of Sciences, Fričova 298,
CZ-251 65 Ondřejov, Czech Republic  Department of Theoretical Physics and
Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic  P.
Škoda Astronomical Institute of the Czech Academy of Sciences, Fričova 298,
CZ-251 65 Ondřejov, Czech Republic  M. Wolf Astronomical Institute, Charles
University, Prague, V Holešovičkách 2, CZ-180 00 Praha 8, Czech Republic  P.
Zasche Astronomical Institute, Charles University, Prague, V Holešovičkách 2,
CZ-180 00 Praha 8, Czech Republic  M. Zejda Department of Theoretical Physics
and Astrophysics, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic

###### Abstract

The results of the first synoptic survey of novae in the barred spiral and
starburst galaxy, M83 (NGC 5236), are presented. A total of 19 novae and one
background supernova were discovered during the course of a nearly seven-year
survey comprised of over 200 individual nights of observation between 2012
December 12 and 2019 March 14. After correcting for the limiting magnitude and
the spatial and temporal coverage of the survey, the nova rate in M83 was
found to be $R=19^{+5}_{-3}$ yr-1. This rate, when normalized to the $K$-band
luminosity of the galaxy, yields a luminosity-specific nova rate,
$\nu_{K}=3.0^{+0.9}_{-0.6}\times 10^{-10}$ yr${}^{-1}~{}L_{\odot,K}^{-1}$. The
spatial distribution of the novae is found to be more extended than the
overall galaxy light suggesting that the observed novae are likely dominated
by a disk population. This result is consistent with the observed nova light
curves which reveal that the M83 novae are on average more luminous at maximum
light and fade faster when compared with novae observed in M31. Generally, the
more luminous M83 novae were observed to fade more rapidly, with the complete
sample being broadly consistent with a linear Maximum-Magnitude vs Rate of
Decline relation.

Cataclysmic variable stars (203) – Classical Novae (251) – Galaxies (573) –
Novae (1127) – Time Domain Astronomy (2109)

††facilities: 1.54-m Danish Telescope, La Silla††software: APHOT (Pravec et
al., 1994), IRAF (Tody, 1986), ISIS (Alard & Lupton, 1998)

##  1 Introduction

Nova eruptions are the result of quasi-periodic thermonuclear runaways (TNRs)
on the surfaces of accreting white dwarfs in semidetached binary systems
(e.g., see Starrfield et al., 2016, and references therein), with eruptions
recurring on timescales as short as a year (Kato et al., 2014)111 Novae where
more than one eruption has been recorded (i.e., systems with recurrence times
less than of order a century) are collectively referred to a “Recurrent
Novae”, although the terminology is somewhat misleading given that all systems
are believed to be recurrent.. Novae are among the most luminous optical
transients known, with absolute magnitudes at the peak of the eruption
averaging M${}_{V}\sim-7.5$, and reaching M${}_{V}\sim-10$ for the most
luminous systems. As a result, they can be seen to great distances and have
been studied in external galaxies for more than a century (e.g., in M31,
Ritchey, 1917; Hubble, 1929).

The observed properties of novae are predicted theoretically to depend
strongly on the structure of the progenitor binary system. The mass of the
white dwarf and the rate of accretion onto its surface are the most important
parameters, ultimately determining the ignition mass required to initiate the
TNR (e.g., Nomoto, 1982; Townsley & Bildsten, 2005; Kato et al., 2014).
Systems with high mass white dwarfs accreting at high rates require the lowest
ignition masses, and thus have the shortest recurrence times between
successive eruptions. The small ignition masses result in eruptions that eject
relatively little mass resulting in a rapid photometric evolution (i.e., they
produce “fast” novae).

The mass accretion rate is strongly influenced by the evolutionary state of
the companion star, with evolved stars typically transferring mass to the
white dwarf at a higher rate compared with systems containing main-sequence
companions. The amplitudes of the eruptions are also strongly dependent on the
nature of the companion star, being as small as $\sim$5 magnitudes as in the
case of the M31 recurrent nova M31N 2008-12a (Darnley et al., 2017), or as
large as $\sim$20 mag as was observed for the Galactic nova, V1500 Cyg
(Duerbeck, 1987). Finally, it is also thought that the chemical composition of
the accreted material may also play an important role in determining the
observed properties of nova eruptions (e.g., Starrfield et al., 2016, and
references therein).

Given that the nature of the nova eruptions are predicted to depend
sensitively on the properties of the progenitor binary, it is reasonable to
expect that the observed properties of a novae in a given galaxy might vary
with the underlying stellar population. In particular, the specific rate of
nova eruptions can be expected to be much higher in a population of novae
containing higher mass white dwarfs, where the average recurrence times are
relatively short. An early attempt to explore this question was undertaken by
Yungelson et al. (1997) who computed population synthesis models that
predicted that young stellar populations, which contain on average more
massive white dwarfs, should produce nova eruptions at a higher rate compared
with older populations. Thus, late-type, low mass galaxies, with a recent
history of active star formation were predicted to be more prolific nova
producers compared with older, quiescent galaxies.

To date, nova rates have been estimated in well over a dozen galaxies (e.g.,
see Shafter et al., 2014; Shafter, 2019; Della Valle & Izzo, 2020, and
references therein). Taken together, the results do not suggest a simple
relationship between a galaxy’s specific nova rate (usually taken to be its
$K$-band luminosity-specific rate, $\nu_{K}$) and its dominant stellar
population (as reflected by its integrated $B-K$ color). Early work by
Ciardullo et al. (1990); Shafter et al. (2000); Williams & Shafter (2004)
failed to find any correlation between $\nu_{K}$ and Hubble type; however,
della Valle et al. (1994) argued that the bluer, late-type systems such as the
Magellanic Clouds and M33, had higher specific nova rates compared with
earlier type galaxies. More recently, Shara et al. (2016) and Shafter et al.
(2017) have analyzed archival HST imaging data of M87 and made a compelling
case that the specific nova rate in this giant elliptical galaxy is at least
as high, and perhaps higher, than that found in spiral galaxies and the LMC.
Given the uncertainties inherent in measuring extragalactic nova rates,
particularly in galaxies other than the Magellanic Clouds (where the rates are
relatively well constrained by the Optical Gravitational Lensing Experiment
(OGLE, Mróz et al., 2016), it’s fair to say that the question of whether the
specific rates vary systematically with the underlying stellar population has
yet to be answered definitively.

In an attempt to shed further light on how the underlying stellar population
may affect observed nova properties, we have undertaken a multi-year survey of
novae in the grand-design spiral M83 (NGC 5236) – also known as the Southern
Pinwheel galaxy – a metal-rich, late-type barred spiral galaxy of
morphological type SAB(s)c (de Vaucouleurs et al., 1991).

Table 1: Log of Observations

UT Date | Julian Date | Limiting mag |
---|---|---|---
(yr mon day) | (2,450,000+) | ($R$) | NotesaaAll observations were made with the 1.54-m Danish Telescope at La Silla. Observer(s): (1) K. Hornoch
2012 12 12.361 | 6273.861 | 22.3 | 1
2012 12 18.368 | 6279.868 | 22.7 | 1
2012 12 22.352 | 6283.852 | 22.5 | 1
2012 12 23.345 | 6284.845 | 22.9 | 1
2012 12 28.314 | 6289.814 | 21.8 | 1

Note. — Table 1 is published in its entirety in the machine-readable format. A
portion is shown here for guidance regarding its form and content.

Figure 1: Top panel: A $75^{\prime\prime}\times 57^{\prime\prime}$ portion of
a median-combined image from our survey taken on the night of 2014 Feb 11 UT.
Middle panel: An image of the same region of the galaxy one month later on
2014 Mar 11 UT. Bottom panel: The difference of the two images as computed by
the ISIS image subtraction software, clearly showing the nova M83N 2014-03a.

##  2 Observations

Our survey for novae in M83 spanned approximately seven years between 2012
December 12 and 2019 March 14. During this time we acquired a total of 205
nightly images of the galaxy. All observations were acquired with the 1.54-m
Danish reflector at the La Silla observatory using the DFOSC $2048\times 2048$
CCD imager. The telescope-detector combination resulted in final images
covering a square area approximately $13.5^{\prime}$ on a side, with a spatial
resolution of 0.396 arcsec pixel-1. In visual light, M83 has an apparent size
of $12.9^{\prime}\times 11.5^{\prime}$, assuring that our observations cover
essentially all of the galaxy. However, as described later in section 5.3, the
outer halo of M83 may extend slightly beyond our survey’s spatial coverage.

The vast majority of our images were taken through a broad-band $R$ filter,
with occasional exposure taken through an $I$ filter. We chose to conduct our
primary survey in the $R$-band both because novae develop strong H$\alpha$
emission shortly after eruption, which adds to the flux in the $R$-band, and
because the quantum efficiency of the CCD detector reaches a peak near the
$R$-band. A complete log of our observations is given in Table 1.

###  2.1 Image Processing

All images were pipeline processed in the usual manner by first subtracting
the bias and dark current, and then flat-fielding the individual images to
remove the high-frequency, pixel-to-pixel variations using APHOT (a synthetic
aperture photometry and astrometry software developed by M. Velen and P.
Pravec at the Ondřejov observatory, Pravec et al., 1994). To eliminate cosmic-
ray artifacts in our nightly images, we obtained a series of 120-s images that
were later spatially registered and median stacked using
SIPS222https://www.gxccd.com/cat?id=146&lang=409 to produce a final image for
a given night of observation intended for nova searching. Photometric and
astrometric measurements of the novae were done using APHOT on spatially
registered and stacked nightly images.

Figure 2: Top panel: A $30^{\prime\prime}\times 30^{\prime\prime}$ portion of our survey image from the night of 2013 Jan 18 UT (North up, East left). The likely supernova is located approximately $2^{\prime\prime}$ E and $1.6^{\prime\prime}$ S of the center of the anonymous spiral galaxy. For comparison, the bottom panel shows an identical $30^{\prime\prime}\times 30^{\prime\prime}$ portion of deep Sloan $r$-band image of the galaxy field taken on 2010 Sep 28 UT by J. L. Prieto using the MEGACAM on the 6.5-m Magellan II - Clay telescope at Las Campanas Observatory.  Figure 3: The light curve of the transient source near the anonymous background galaxy. The proximity of the transient source to the galaxy, coupled with the slow rise to maximum light ($\mathrel{\hbox{\hbox to0.0pt{\hbox{\lower 4.0pt\hbox{$\sim$}}\hss}\hbox{$>$}}}10$ d), strongly suggests that the object is a supernova (likely of Type Ia) in the background galaxy, and not a nova in M83. The red triangle represents an upper limit on the flux when the transient was not detected.  Table 2: M83 Novae  |  | R.A. (2000.0) | Decl. (2000.0) | R.A. offset | Decl. offset |
---|---|---|---|---|---|---
Nova # | Nova name | (h m s) | (∘ ′ ′′) |  $\Delta\alpha$ cos($\delta$) (′′) |  $\Delta\delta$ (′′) | Notesaa (1) (Hornoch, 2013a); (2) (Hornoch, 2013b), (see also Prieto & Morrell, 2013, for spectroscopic classification); (3) K. Hornoch; (4) K. Hornoch and M. Skarka; (5) A. W. Shafter, K. Hornoch, and M. Wolf; (6) K. Hornoch and J. Vraštil; (7) K. Hornoch and M. Zejda; (8) K. Hornoch and E. Paunzen; (9) K. Hornoch, E. Paunzen, and M. Zejda; (10) K. Hornoch, P. Zasche, E. Paunzen, and J. Liška; (11) K. Hornoch, M. Wolf, L. Pilarčík, and J. Vraštil; (12) (Hornoch & Paunzen, 2018); (13) (Hornoch & Kucakova, 2018); (14) (Hornoch & Kucakova, 2019); (15) (Hornoch et al., 2019).
1 | M83N 2013-01a | 13 36 44.30 | $-29~{}50~{}33.9$ | $-216.2$ | $82.8$ | 1
2 | M83N 2013-01b | 13 37 03.42 | $-29~{}53~{}39.8$ | $32.5$ | $-103.1$ | 2
3 | M83N 2013-01c | 13 37 06.75 | $-29~{}56~{}15.5$ | $75.8$ | $-258.8$ | 3
4 | M83N 2013-01d | 13 37 10.51 | $-29~{}45~{}19.6$ | $124.8$ | $397.1$ | 3
5 | M83N 2013-03a | 13 36 58.76 | $-29~{}53~{}22.6$ | $-28.1$ | $-85.9$ | 4
6 | M83N 2013-04a | 13 37 05.80 | $-29~{}48~{}11.4$ | $63.5$ | $225.3$ | 5
7 | M83N 2014-01a | 13 37 17.86 | $-29~{}53~{}47.7$ | $220.3$ | $-111.0$ | 6
8 | M83N 2014-01b | 13 37 05.81 | $-29~{}56~{}02.0$ | $63.6$ | $-245.3$ | 3
9 | M83N 2014-01c | 13 37 15.48 | $-29~{}56~{}10.9$ | $189.3$ | $-254.2$ | 3
10 | M83N 2014-03a | 13 37 08.88 | $-29~{}50~{}16.6$ | $103.6$ | $100.1$ | 7
11 | M83N 2015-01a | 13 36 35.15 | $-29~{}56~{}41.0$ | $-335.1$ | $-284.3$ | 8
12 | M83N 2015-04a | 13 37 08.42 | $-29~{}51~{}13.5$ | $97.6$ | $43.2$ | 9
13 | M83N 2016-02a | 13 36 53.01 | $-29~{}56~{}19.9$ | $-102.8$ | $-263.2$ | 10
14 | M83N 2016-02b | 13 36 45.52 | $-29~{}55~{}57.2$ | $-200.2$ | $-240.5$ | 10
15 | M83N 2016-03a | 13 36 36.15 | $-29~{}51~{}44.9$ | $-322.2$ | $11.8$ | 11
16 | M83N 2018-01a | 13 37 09.78 | $-29~{}56~{}57.6$ | $115.2$ | $-300.9$ | 12
17 | M83N 2018-02a | 13 37 01.26 | $-29~{}55~{}48.2$ | $4.4$ | $-231.5$ | 13
18 | M83N 2019-02a | 13 37 03.82 | $-29~{}48~{}21.7$ | $37.7$ | $215.0$ | 14
19 | M83N 2019-03a | 13 37 18.18 | $-29~{}48~{}29.0$ | $224.6$ | $207.7$ | 15

##  3 Nova Detection

Novae are transient sources that can be effectively identified through careful
comparisons between images from synoptic imaging surveys having a variable
cadence such as the one we have conducted. Coarse temporal coverage is
sufficient to identify transient sources, but sufficiently dense coverage is
required to measure the light curves. The light curves provide assurance that
the detected transients are indeed novae and not some other variable objects,
such as Luminous Blue Variables (LBVs), or the more common Luminous Red
Variables (i.e., Mira variables) that can mimic novae in poorly sampled
surveys. Novae can also be distinguished from other variable stars through
their $V-I$ color, which is the reason we augmented our data with occasional
$I$-band images. The strong H$\alpha$ emission contributing to the $R$-band
flux results in a $V-I$ color that is significantly bluer than that of the
extremely red Mira variables, which are characterized by
$V-I\mathrel{\hbox{\hbox to0.0pt{\hbox{\lower
4.0pt\hbox{$\sim$}}\hss}\hbox{$>$}}}2$ (e.g., see Bhardwaj et al., 2019).

Nova candidates were identified using two different procedures: First, through
a direct comparison (blinking) of images from different epochs, and secondly,
through a comparison of images from differing epochs using the image
subtraction software, ISIS (Alard & Lupton, 1998). Direct comparison of the
images proved to be a very effective technique for identifying novae in the
outer regions of the galaxy; however, in regions of the galaxy with high
surface brightness (i.e., within $\sim 3^{\prime}$ of the nucleus and in some
very dense regions of the spiral arms) we had to modify our approach. To
detect novae in regions of high background, we first created smoothed (median-
filtered) images by sliding a $11\times 11$ pixel box across the image, pixel-
by-pixel, replacing the central pixel by the median of all 121 pixels in the
box. This median-smoothed image was then subtracted from the original image to
produce a median-subtracted image with greatly reduced background variations.
These median-subtracted images were once again blinked by eye.

In addition to blinking median-subtracted images, we also employed image
subtraction routines from the ISIS image processing package, which increased
our sensitivity to novae in regions of high background. Figure 1 shows an
example of our ISIS nova detection procedure. The top panel shows a
$75^{\prime\prime}\times 57^{\prime\prime}$ portion of a median-combined image
from 2014 Feb 11 UT. The middle panel shows an image of the same region of the
galaxy one month later on 2014 Mar 11 UT. The nova, M83N 2014-03a, is visible
in the March image, and clearly visible in the ISIS subtracted image at the
bottom.

We discovered a total of 19 novae over the course of our seven-year survey of
M83. Their positions and offsets from the center of M83 (R.A. =
$13^{h}37^{m}00.^{s}919$, Decl. =
$-29^{\circ}51^{\prime}56.^{\prime\prime}74$, J2000) are given in Table 2.
These detections represent the first novae to be reported in M83. It is worth
noting that during our inspection of the images we found one transient source
located extremely close ($\sim 2^{\prime\prime}$ E and $\sim
1.6^{\prime\prime}$ S) to the center of an anonymous background spiral galaxy
(see Figure 2). The background galaxy, which is located at R.A. =
$13^{h}~{}37^{m}~{}19.59^{s}$, Decl. =
$-29^{\circ}~{}53^{\prime}~{}47.1^{\prime\prime}$, lies $242.3^{\prime\prime}$
E and $110.3^{\prime\prime}$ S from the center of M83. While it is possible
that this transient could be a nova in M83, given its proximity to the nucleus
of the spiral, we consider it far more likely to have been a supernova in the
galaxy discovered serendipitously during the course of our survey (Hornoch et
al., 2013). This assessment is backed up by the light curve of the transient
(see Figure 3), which shows the relatively slow rise to peak brightness
characteristic of supernovae, but not novae. A comparison with the supernova
light curve templates given in Doggett & Branch (1985) suggests that the
transient is likely a supernova of Type Ia. In view of these considerations,
we have excluded this source from our final tally of M83 novae.

###  3.1 Photometry

Table 3: M83 Nova Photometry

(UT Date) | (JD - 2,450,000) | Mag | Unc. | Band
---|---|---|---|---
2013-nova1 = 2013-01a
2012 06 01.138 | 6079.638 | [22.6 |  | R
2012 12 12.361 | 6273.861 | [22.3 |  | R
2012 12 18.368 | 6279.868 | [22.7 |  | R
2012 12 23.345 | 6284.845 | [22.9 |  | R
2012 12 28.314 | 6289.814 | 21.0 | 0.15 | R
2012 12 28.316 | 6289.816 | 21.1 | 0.2 | I

Note. — Table 3 is published in its entirety in the machine-readable format. A
portion is shown here for guidance regarding its form and content.

Figure 4: Light curves for 18 of the 19 novae discovered in our survey plotted
with consistent axes scales in order to better reveal the relative photometric
properties of the novae. The one nova not shown is M83N 2015-04a, where the
nova was only seen in one epoch ($R=21.4\pm 0.25$ on JD 2,457,120.915). The
red triangles represent upper limits on the flux at times when the novae were
not detected. Figure 5: The positions of the 19 novae discovered in our survey
superimposed on an image of M83. The blue squares represent relatively “fast”
novae with $t_{2}<25$ d, while the red circles show “slow” novae with
$t_{2}>25$ d. The white triangles show the two novae without sufficient light
curve coverage to determine a rate of decline from peak brightness. We find no
correlation between speed class and spatial position within the galaxy, and it
is clear that the novae are more spatially extended than is the background
galaxy light.

Instrumental magnitudes for all nova candidates were determined by summing the
fluxes in 2′′-in diameter circular apertures in all epochs in which they were
visible. Calibrated $R$-band magnitudes were then determined by differential
photometry with respect to a set of six secondary standard stars in the M83
field. Both the $R$-band and $I$-band magnitudes of the secondary standard
stars were photometrically calibrated by us using the same instrumentation as
we used for the survey. As primary standards we used the stars and their
magnitudes published in Landolt (1992). We observed both the primary standards
and the M83 field during one night under excellent photometric conditions to
get properly calibrated the secondary standards in the field of M83 which
allow us to obtain photometry of the novae also in non-photometric nights.

The calibrated magnitudes of all 19 novae discovered as part of our survey, on
all nights where they were visible, are presented in Table 3. The temporal
sampling of our survey was sufficient to produce useful $R$-band light curves
for all but one of the 19 novae. The light curves for these 18 novae having
multiple epochs of observation are shown in Figure 4. The properties of the
light curves (i.e., their peak magnitudes and fade rates) will be explored
further in section 6.

##  4 The Spatial Distribution of M83 Novae

Table 4: M83 Surface PhotometryaaDigitized from Kuchinski et al. (2000). P.A. = 80∘; Ellipticity, $b/a=0.9$ assumed for all values. Semimajor axis | $\Sigma_{R}$ |  | Semimajor axis | $\Sigma_{R}$
---|---|---|---|---
(arcsec) | (mag/arcsec2) |  | (arcsec) | (mag/arcsec2)
0.4 | 15.90 |  | 104.1 | 20.29
2.7 | 16.01 |  | 107.7 | 20.25
4.4 | 16.42 |  | 110.7 | 20.25
7.1 | 16.98 |  | 113.8 | 20.25
9.3 | 17.59 |  | 117.4 | 20.25
11.5 | 17.91 |  | 121.8 | 20.29
13.7 | 18.17 |  | 125.3 | 20.33
16.3 | 18.45 |  | 128.8 | 20.38
18.1 | 18.65 |  | 131.5 | 20.46
20.7 | 18.80 |  | 137.7 | 20.55
22.1 | 18.91 |  | 142.5 | 20.61
24.7 | 18.99 |  | 148.2 | 20.68
25.6 | 19.06 |  | 157.1 | 20.74
27.4 | 19.19 |  | 165.0 | 20.85
29.6 | 19.25 |  | 175.6 | 20.94
31.8 | 19.30 |  | 185.7 | 21.02
33.5 | 19.38 |  | 199.4 | 21.18
36.2 | 19.45 |  | 209.1 | 21.26
38.4 | 19.51 |  | 222.4 | 21.37
41.0 | 19.60 |  | 236.0 | 21.50
43.2 | 19.64 |  | 245.3 | 21.61
46.8 | 19.68 |  | 250.2 | 21.72
49.9 | 19.73 |  | 259.0 | 21.74
52.9 | 19.81 |  | 268.2 | 21.85
56.9 | 19.86 |  | 277.1 | 21.95
60.9 | 19.92 |  | 287.7 | 22.11
65.3 | 19.99 |  | 299.1 | 22.28
69.7 | 20.03 |  | 320.0 | 22.56bbextrapolated value
73.2 | 20.10 |  | 350.0 | 22.96bbextrapolated value
78.5 | 20.14 |  | 400.0 | 23.63bbextrapolated value
86.0 | 20.20 |  | 450.0 | 24.31bbextrapolated value
90.4 | 20.25 |  | 500.0 | 24.98bbextrapolated value
93.5 | 20.27 |  | … | …
98.4 | 20.27 |  | … | …

Figure 5 shows the spatial distribution of the 19 novae discovered in M83
superimposed on a (negative) image of the galaxy. It is immediately apparent
that the novae seem to be more spatially extended than the galaxy light. We
can explore this impression more quantitatively by comparing the cumulative
distribution of the novae with that of the background $R$-band light, as shown
in Figure 6. The cumulative background light has been determined by
integrating the surface photometry from Table 4, which we have derived from
digitizing the radial surface brightness profiles given in Figure 4 of
Kuchinski et al. (2000). Since the high surface brightness near the nucleus of
the galaxy renders us effectively blind to novae within $\sim
30^{\prime\prime}$ of the center of the galaxy, and likely significantly
incomplete within $60^{\prime\prime}$, we have considered three cumulative
light distributions starting with inner radii at
$R_{\mathrm{i}n}=30^{\prime\prime}$, $R_{\mathrm{i}n}=60^{\prime\prime}$, and
$R_{\mathrm{i}n}=90^{\prime\prime}$. Regardless of the adopted inner radius,
the cumulative background light clearly falls off faster than the observed
nova distribution. This result is formally confirmed by Kolmogorov-Smirnov
(K-S) tests ($p=1.6\times 10^{-3}$, $p=3.7\times 10^{-3}$, and $p=1.1\times
10^{-2}$ for cases where we considered inner radii of
$R_{in}=30^{\prime\prime}$, $R_{in}=60^{\prime\prime}$, and
$R_{in}=90^{\prime\prime}$, respectively), suggesting we can reject the null
hypothesis (i.e., the nova and light distributions were drawn from the same
parent distribution) with $\mathrel{\hbox{\hbox to0.0pt{\hbox{\lower
4.0pt\hbox{$\sim$}}\hss}\hbox{$>$}}}99\%$ confidence. Thus, it appears that
the novae detected in M83 are primarily associated with a more extended disk
population of the galaxy.

Before considering possible explanations for why the novae do not appear to
follow the overall background light in M83, it is important to rule out the
possibility that we may be missing a significant fraction of novae in the
inner regions of the galaxy due to the difficulty in detecting them against
the high central surface brightness. We explore this possibility below in our
determination of the nova rate in M83, which also depends critically on the
overall completeness of our survey.

Figure 6: The cumulative distribution of the isophotal radii of the 19 novae
(black histogram) compared with the cumulative galaxy $R$-band light for three
representative values of the inner radius, $R_{in}$ (shown in red).

##  5 The Nova Rate in M83

As transient objects, novae are visible for a limited time that depends both
on the intrinsic properties of the novae themselves (e.g., their peak
luminosities, fade rates, and spatial location within the galaxy) and on
parameters inherent to the survey itself; specifically, the temporal sampling
and survey depth (the effective limiting magnitude). Whether or not a given
nova in M83 can potentially be detected depends on a combination of its peak
apparent magnitude, its position within the galaxy, and on the limiting
magnitude of our survey images at that location in the galaxy. Then, whether
it will actually be detected depends on the time it erupted relative to the
dates of our observations and the rate of decline in the nova’s brightness.
Given a population of novae with a variety of light curve properties (peak
luminosities and fade rates), distributed at different positions within the
galaxy, and observed at different times, the only practical way of determining
the number of novae we can expect to see in our survey given an intrinsic
rate, $R$, is to conduct numerical (Monte Carlo) simulations. Before the
simulations can be performed, the first step is to determine the effective
completeness of the survey at a given magnitude, $C(m)$.

###  5.1 The Effective Limiting Magnitude of the Survey

A determination of the limiting magnitude of our survey images is complicated
by the fact that the galaxy background surface brightness is highly variable
and that the spatial distribution of the novae cannot be assumed to be uniform
across the survey images. Thus, no one limiting magnitude can represent the
coverage of a given image. We have approached this problem following the
procedure described in our earlier work on NGC 2403 (Franck et al., 2012).
Specifically, we have conducted artificial nova tests on a representative
image (hereafter the fiducial image) under the assumption that the spatial
distribution of the artificial novae follows the background light of the
galaxy.

The artificial novae were generated using tasks in the IRAF DAOPHOT package,
which enabled us to match the point-spread-functions of the real stars in the
image. Using the routine addstar, the fiducial image was then seeded with 100
artificial novae having apparent magnitudes randomly distributed within each
of a total of eight, 0.5-mag wide, bins. For each of the magnitude bins, the
artificial novae were distributed randomly, but with a spatial density that
was constrained to follow the integrated background galaxy light of M83. We
then searched for the artificial novae using the same procedures that we
employed in identifying the real novae. The completeness at the fainter
magnitudes was somewhat higher using the ISIS image subtraction analysis, but
was generally consistent with the results from a direct comparison of median-
subtracted images.

The fraction of novae recovered from the two search techniques in each
magnitude bin yielded the completeness functions shown in Figure 7. Given that
we discovered the same number of novae in M83 employing both techniques, we
have chosen to take the average completeness in a given magnitude bin (the
heavy line in Figure 7) to form the basis of the completeness function,
$C(m)$. To allow for uncertainty in magnitude bins where the completeness
functions differ (the shaded regions), we randomly sample allowed values of
$C(m)$ in the analysis to follow. This completeness function can be
generalized to any epoch, $i$, of observation by applying a shift, $\Delta
m_{i}$ ($=m_{lim,0}-m_{lim,i}$), which represents the difference in the
limiting magnitudes (as measured by the faintest star that could be reliably
detected near the perimeter of the image away from the galaxy) of our fiducial
image and that of the $i$-th epoch image. Thus, for any epoch, $i$, we have
$C_{i}(m)=C(m+\Delta m_{i})$.

Figure 7: The survey completeness as a function of the $R$-band apparent
magnitude, $C(m)$, as determined from our artificial nova tests. The red
dashed line shows the completeness from the ISIS image subtraction procedure,
the blue dot-dash line shows the completeness using the median-subtraction
technique, with the heavy black line shows the average completeness in each
magnitude bin. The shaded region shows the range of completeness in each
magnitude bin bounded by the two search techniques and used in our Monte Carlo
nova rate simulations.

###  5.2 The Monte Carlo Simulation

As in our earlier extragalactic nova studies (e.g., Franck et al., 2012; Güth
et al., 2010; Coelho et al., 2008; Williams & Shafter, 2004), we have employed
a Monte Carlo simulation to compute the number of M83 novae that we would
expect to observe during the course of our survey.

For a given assumed annual nova rate, $R$, we begin by producing trial novae
erupting at random times throughout the time span covered by our survey, each
having a peak luminosity and fade rate that has been selected at random from a
large sample of known $R$-band light curve parameters. Ideally, we would like
to use light curve parameters specific to the full population of M83 novae,
but such an unbiased sample does not exist. Instead, we have used the M83
light curve parameters from our observations given in Table 5, augmented with
additional $R$-band light curve parameters from the M31 light curves observed
by Shafter et al. (2011).

Table 5: Light Curve Parameters Nova | mR | MRaaAssuming a distance modulus $\mu_{\circ}(\mathrm{M}83)=28.34\pm 0.14$ (Tully et al., 2016) and a foreground $R$-band extinction of 0.14 mag (Schlafly & Finkbeiner, 2011). | $f_{R}$ | $t_{2}(R)$
---|---|---|---|---
(M83N) | (peak) | (peak) | (mag d-1) | (d)
2013-01a | $19.58\pm 0.04$ | $-8.90\pm 0.08$ | $0.103\pm 0.004$ | $19.3\pm 0.7$
2013-01b | $21.11\pm 0.12$ | $-7.37\pm 0.14$ | $0.115\pm 0.018$ | $17.5\pm 2.7$
2013-01c | $20.27\pm 0.06$ | $-8.21\pm 0.09$ | $0.046\pm 0.002$ | $43.2\pm 2.1$
2013-01d | $20.80\pm 0.04$ | $-7.69\pm 0.08$ | $0.036\pm 0.002$ | $54.8\pm 2.9$
2013-03a | $21.66\pm 0.05$ | $-6.82\pm 0.08$ | $0.013\pm 0.002$ | $157.5\pm 21.1$
2013-04a | $20.16\pm 0.05$ | $-8.32\pm 0.08$ | $0.123\pm 0.015$ | $16.3\pm 2.1$
2014-01a | $19.41\pm 0.11$ | $-9.08\pm 0.13$ | $0.256\pm 0.014$ | $7.8\pm 0.4$
2014-01b | $21.68\pm 0.06$ | $-6.80\pm 0.09$ | $0.033\pm 0.004$ | $60.6\pm 7.0$
2014-01c | $18.69\pm 0.05$ | $-9.80\pm 0.08$ | $0.326\pm 0.012$ | $6.1\pm 0.2$
2014-03a | $19.48\pm 0.06$ | $-9.00\pm 0.09$ | $0.169\pm 0.012$ | $11.9\pm 0.9$
2015-01a | $20.63\pm 0.03$ | $-7.85\pm 0.08$ | $0.085\pm 0.004$ | $23.5\pm 1.0$
2016-02a | $20.83\pm 0.07$ | $-7.65\pm 0.10$ | $0.072\pm 0.008$ | $27.7\pm 2.9$
2016-02b | $20.68\pm 0.06$ | $-7.80\pm 0.09$ | $0.058\pm 0.005$ | $34.7\pm 3.1$
2016-03a | $19.90\pm 0.08$ | $-8.59\pm 0.11$ | $0.157\pm 0.013$ | $12.8\pm 1.1$
2018-01a | $20.89\pm 0.05$ | $-7.60\pm 0.09$ | $0.067\pm 0.006$ | $29.9\pm 2.5$
2018-02a | $21.47\pm 0.10$ | $-7.01\pm 0.12$ | $0.024\pm 0.007$ | $83.3\pm 22.6$
2019-02a | $19.91\pm 0.09$ | $-8.57\pm 0.11$ | $0.181\pm 0.016$ | $11.0\pm 1.0$

Adopting a distance modulus to M83 of $\mu_{0}=28.34\pm 0.14$, which
represents the mean of the Cepheid and the tip of the red giant branch
distances from the recent study by Tully et al. (2016), enables us to compute
the expected apparent magnitude distribution at any given epoch, $i$, during
our survey, $n_{i}(m,R)$. To account for uncertainty in the distance, our
numerical simulations also randomly select values of the distance modulus
normally distributed about the mean value. The number of novae expected to be
detectable during the course of our survey, $N_{obs}(R)$, can then be computed
by convolving the simulated apparent magnitude distribution with the
completeness function, $C_{i}(m)$, and then summing over all epochs of
observation:

$N_{\mathrm{o}bs}(R)=\sum_{i}\sum_{m}{C_{i}(m)~{}n_{i}(m,R)}.$ (1)

The intrinsic nova rate in M83, $R$, and its uncertainty can now be determined
through a comparison of the number of novae found in our survey,
$n_{\mathrm{o}bs}=19$, with the number of novae predicted by equation (1). We
explored trial nova rates ranging from $R=1$ to $R=50$ novae per year,
repeating the numerical simulation 105 times for each trial value of $R$. The
number of matches, $M(R)$, between the predicted number of observable novae,
$N_{obs}(R)$, and the actual number of novae discovered in our survey,
$n_{obs}$ = 19, was recorded for each trial value of $R$. The number of
matches was then normalized by the total number of matches for all $R$ to give
the probability distribution function, $P(R)=M(R)/\sum_{R}{M(R)}$ shown in
Figure 8. The most probable nova rate in the portion of the galaxy covered by
our survey images is 18${}^{+5}_{-3}$ yr-1, where the error range (1$\sigma$)
for the asymmetrical probability distribution has been computed assuming it
can be approximated by a bi-Gaussian function.

Figure 8: The probability distribution for the nova rate in M83 as determined
from our Monte Carlo simulations. The peak of the distribution represents the
most likely nova rate in M83. Assuming a bi-Gaussian form for the probability
distribution yields a nova rate and associated $1\sigma$ uncertainty of
$R_{M83}=18^{+5}_{-3}$ novae per year.

The $K$-band photometry of M83 from the Two-Micron All Sky Survey (2MASS)
suggests that the extended halo may extend out to a distance of $r_{tot}\sim
8.5^{\prime}$ from the center of M83. Thus, it is possible that our survey
images may be missing a small fraction ($\mathrel{\hbox{\hbox
to0.0pt{\hbox{\lower 4.0pt\hbox{$\sim$}}\hss}\hbox{$<$}}}$5%) of the light
from the extended halo of M83. Under the assumption that we are sampling
$0.95\pm 0.05$ of the total M83 light, we estimate the global nova rate for
M83 to be $R_{M83}=19^{+5}_{-3}$ yr-1.

###  5.3 The Luminosity-Specific Nova Rate

In order to compare the nova rates between different galaxies or different
stellar populations, the rates must first be suitably normalized. Ideally, it
would be appropriate to normalize the rates by the mass of stars in the region
surveyed, but the mass cannot be measured directly. As a proxy for the mass in
stars, it has become standard practice to normalize the nova rate by the
infrared $K$-band luminosity of the galaxy. In the case of M83, the integrated
apparent $K$-band magnitude as measured by 2MASS is $K=4.62\pm 0.03$. Given
the distance modulus, $\mu_{0}=28.34\pm 0.14$, and taking the absolute
$K$-band magnitude of the sun to be $M_{K}=3.27\pm 0.02$ (Willmer, 2018), we
find that M83 has an absolute magnitude in the $K$-band of $M_{K}=-23.72$, and
a corresponding $K$-band luminosity of $(6.32\pm 0.84)\times 10^{10}$ L⊙,K.
Since we estimate that our survey covers $0.95\pm 0.05$ of the entire galaxy
where we have found an overall nova rate of $18^{+5}_{-3}$ yr-1, we arrive at
a $K$-band luminosity-specific nova rate for M83 of
$\nu_{K}=(3.0^{+0.9}_{-0.6})\times 10^{-10}$ yr-1 L${}_{K,\odot}^{-1}$.

As recently reviewed by Shafter (2019) and Della Valle & Izzo (2020) prior to
the present study, luminosity-specific nova rates had been measured for a
total of 15 external galaxies. Figure 9 shows our value of $\nu_{K}$ for M83,
along with the values for the other 15 galaxies taken from Table 7.3 in
Shafter (2019), plotted as a function of the $B-K$ color of the host galaxy.
The specific nova rate for M83 is consistent with those of other spiral
galaxies with measured nova rates. As we have noted in previous studies,
despite the relatively high $\nu_{K}$ values reported for the Magellanic
Clouds and M87 – galaxies with very different Hubble types – there is no
compelling evidence that $\nu_{K}$ varies systematically with the underlying
stellar population.

Figure 9: The luminosity-specific nova rates of all 16 galaxies where nova
rates are available plotted as a function of the galaxy $B-K$ color. The data
have been taken from Table 7.3 of Shafter (2019) with the exception of the
value for M83 from the current study, which is shown as a red square.

##  6 Light Curve Properties

As described in section 3.1, the temporal coverage during the course of our
survey was sufficiently dense to enable us to measure $R$-band light curves
for 18 of the 19 M83 novae that were detected. These light curves, drawn from
an equidistant sample of novae, offer a rare opportunity to explore the
relationship between a nova’s peak luminosity and its rate of decline from
maximum light, and thus test whether or not the novae obey the canonical (but
recently questioned) Maximum-Magnitude versus Rate-of-Decline (MMRD) relation.

###  6.1 The MMRD Relation

The MMRD relation for novae was first introduced by Mclaughlin (1945), who
discovered that the most luminous members of a sample of 30 (mostly Galactic)
novae faded more quickly than did their fainter counterparts333In his 1945
paper McLaughlin referred to the MMRD relation as the “life-luminosity”
relation for novae.. He was able to quantify a linear MMRD relation of the
form, $M=a+b~{}\mathrm{log}(t_{3})$, where $a$ and $b$ are fitting parameters
and $t_{3}$ is the time it takes a nova to fade 3 magnitudes from maximum
light (in recent years $t_{2}$, which is more easily measured, is often used
as an alternative). Over the years the MMRD relation has been calibrated many
times, both in the Galaxy (e.g., Cohen, 1985; Downes & Duerbeck, 2000), and in
nearby galaxies such as M31 (e.g., Capaccioli et al., 1989; Shafter et al.,
2011), and has often been used as a means for determining the distances to
novae where the apparent magnitude at maximum light and the fade rate have
been measured.

Over the years it has become increasingly apparent that there is significant
scatter in the MMRD, with the existence of the relation itself being called
into question, initially by Kasliwal et al. (e.g., 2011) who found that a
number of M31 novae observed with the Palomar Transient Factory (PTF) appeared
to fall below the canonical MMRD relation (but, see Della Valle & Izzo (2020)
for a different interpretation.). Recently, it has become clear that a small
subset of novae, typically those with massive white dwarfs that are accreting
at high rates (e.g., recurrent novae) fade rapidly despite having relatively
low peak luminosities, and thus deviate sharply from the MMRD relation. A good
example is the M31 recurrent nova M31N 2008-12a (Darnley et al., 2014; Tang et
al., 2014). Given that such systems do in fact exist, it is clear that not all
novae will follow a universal MMRD relation. On this basis it has been
recently suggested that the notion of an MMRD relation should be abandoned
altogether Schaefer (2018). However, the question of whether it is useful to
continue to refer to an MMRD relation would seem to depend on the relative
frequency of outliers. If the so-called “Faint and Fast” (FFN) novae, such as
M31N 2008-12a, are intrinsically rare, then continuing to refer to an MMRD
might make sense when considering the behavior of the majority of (non
recurrent) novae. On the other hand, if such systems are relatively common,
but just missed in most surveys that lack the depth and cadence to discover
them, then perhaps the existence of an MMRD relation would be best considered
as resulting from an observational selection effect. In either case, it
appears that broadly speaking, luminous novae do on average fade more quickly
than do their low luminosity counterparts.

Figure 10 shows the MMRD relation for the 17 novae in M83 where the light
curves were sufficiently complete to allow a measurement of the peak magnitude
and the rate of decline (here measured as $t_{2}$, the time for the nova to
fade 2 mags from peak). Although there is significant scatter as expected,
there is no question that a general trend, where the more luminous novae fade
more quickly, is apparent. The best-fitting linear MMRD relation is given by:
$\mathrm{M}_{R}=(-10.79\pm 0.42)+(1.96\pm 0.29)~{}\mathrm{log}~{}t_{2}$. The
M31 $R$-band MMRD relation from the study of Shafter et al. (2011) is shown
for comparison, and is remarkably similar444MMRD relations are sometimes fit
using a more complicated arctan function, which has been shown to provide a
somewhat better fit to data for M31 and the LMC (e.g., see della Valle &
Livio, 1995). Given the limited data in the present study, we have chosen to
employ the traditional linear fit.. Whether or not we are missing a putative
population of FFN novae in M83 is unknown. The question can only be answered
by future studies having greater depth and cadence, such as those that will be
possible with the Large Synoptic Survey Telescope (LSST, Ivezić et al., 2019).

Figure 10: The peak absolute $R$-band magnitudes for the 17 M83 novae with
complete light curves are plotted as a function of the log of the fade rate,
as measured by the time in days a nova takes to fade by 2 magnitudes in the
$R$-band from its peak luminosity, $t_{2}(R)$. The M83 nova sample clearly
displays a correlation between peak nova luminosity and $\mathrm{log}(t_{2})$,
as shown by the black dashed line. The $R$-band MMRD relation for M31 from
Shafter et al. (2011) (red dotted line) is shown for comparison. The two
relations are remarkably similar.

###  6.2 Comparison with the M31 nova population

As part of a comprehensive spectroscopic and photometric survey of novae in
M31, Shafter et al. (2011) determined $R$-band light curve parameters for a
total of 42 novae and found that, as in the case of M83, the M31 nova sample
also generally followed a MMRD relation, albeit with significant scatter (see
Table 6 and Figure 19 in Shafter et al., 2011). The M31 novae are
characterized by a mean absolute magnitude, $\langle M_{R}\rangle=-7.55\pm
0.14$ and $\langle t_{2}(R)\rangle=38^{+6}_{-5}$ d, while their M83
counterparts from Table 5 yield $\langle M_{R}\rangle=-8.06\pm 0.21$ and
$\langle t_{2}(R)\rangle=25^{+6}_{-5}$ d555Since the $t_{2}(R)$ distributions
are highly asymmetric, the values of $\langle t_{2}(R)\rangle$ are computed
from the average of the log$~{}t_{2}(R)$ values for each galaxy..

Figure 11: The cumulative distribution of the $R$-band absolute magnitudes of
M83 novae compared with their M31 counterparts. A K-S test reveals that the
two distributions differ with 94% confidence.

It is interesting to compare the cumulative distributions of the peak
luminosities and fade rates from each galaxy, as shown in Figures 11 and 12.
The results of K-S tests show that the peak luminosity and fade rate
distributions differ between each galaxy with 94% and 74% confidence,
respectively. Thus, there is some evidence that the novae in the M83 sample
are, on average, more luminous at maximum light and perhaps fade somewhat more
rapidly compared with the M31 sample. A possible explanation for this
difference is that M31 is an earlier Hubble type galaxy, SA(s)b, and the nova
population observed by Shafter et al. (2011) was predominately a bulge
population. On the other hand, as discussed earlier, our M83 sample appears to
be primarily associated with the galaxy’s disk. Taken together, figures 11 and
12 provide additional support for the existence of two populations of novae,
as originally suggested for Galactic systems three decades ago by Duerbeck
(1990) and Della Valle & Livio (1998) based on photometric and spectroscopic
observations, respectively.

Figure 12: The cumulative distribution of the fade rate of M83 novae in the
$R$-band compared with their M31 counterparts. A K-S test reveals that the two
distributions differ, but with just 74% confidence.

##  7 Discussion

###  7.1 Uncertainty in the Derived Nova Rate

The determination of extragalactic nova rates is challenging, with many
sources of uncertainty that must be properly considered in the analysis. Among
these, uncertainty in the determination of the survey completeness is perhaps
the most important. As described earlier, the completeness – the fraction of
novae erupting in the galaxy that can be detected in a given survey – depends
quite sensitively on the intrinsic properties of the novae and their actual
distribution within the galaxy under investigation. Since neither of these
factors are known a priori, assumptions concerning both must always be made.

To guard against potential bias in our M83 nova sample, we chose to include
light curve parameters from previous observations of novae in M31 in our Monte
Carlo nova rate simulations. As a check on the sensitivity of the final nova
rate to the inclusion of the M31 light curve parameters, we have also
performed the analysis using only the light curve parameters from the M83
novae discovered in our survey. Despite the differences in the light curve
properties between the two samples discussed in the previous section, the
final nova rate determination is essentially unchanged (the rate ranges from
17 yr-1 to 20 yr-1 when the analysis is restricted to the M83 and M31 light
curve parameters, respectively). In this case, the insensitivity of the nova
rate to the choice of light curve parameters results from the fact that the
M83 novae generally follow an MMRD relation. The M83 novae are on average
brighter compared with their M31 counterparts, and thus easier to detect in
our simulations, but they fade generally more quickly, so they are observable
on average for less time. Thus, the two effects tend to cancel, leaving the
final nova rate insensitive to the choice of light curve parameters.

The form of the nova spatial distribution that we have adopted in the
artificial nova completeness experiments can also affect the final nova rate
computation. In the absence of strong evidence to the contrary, the default
approach – and the one we have followed here – is to assume that the spatial
density of novae follows the surface brightness of the galaxy (i.e., more
light, more novae). However, in the case of M83, it appears that this
assumption may be violated. As shown in Figure 5 the observed M83 nova spatial
distribution is significantly more extended than the galaxy’s $R$-band light.
If this result accurately reflects the intrinsic nova spatial distribution
(i.e., we are not missing novae in the inner regions of the galaxy), our
artificial nova simulations may underestimate the overall completeness of our
survey by placing a greater fraction of the artificial novae in the bright
central regions of the galaxy where they are generally more difficult to
detect. This bias, although we consider it to be small, would have the effect
of slightly overestimating the nova rate determined earlier in our Monte Carlo
simulations.

On the other hand, it is worth noting that M83 is an active star-forming
galaxy (e.g., see Calzetti et al., 1999), which likely interacted $\sim$1-2
GYr ago with the nearby metal-poor dwarf galaxy, NGC 5253, triggering
starbursts in both galaxies (van den Bergh, 1980; Calzetti et al., 1999). The
starburst activity in M83 is concentrated in the spiral arms and near the
nucleus of the galaxy, which is heavily shrouded in dust (Gallais et al.,
1991; Lundgren et al., 2008). These are the same regions of the galaxy where
the high surface brightness and complex structure render the detection of
novae difficult. Thus, despite our careful nova searches, the possibility that
we may be missing some novae in these regions of the galaxy cannot be
definitively ruled out. If such a putative population of heavily-extincted
novae exists, it would not be properly accounted for by our artificial nova
tests, the completeness would be overestimated, and our simulations would then
underestimate the true nova rate.

###  7.2 The Observed Nova Spatial Distribution

As discussed earlier, it was surprising to find that the observed spatial
distribution of novae in M83 did not follow the background light of the
galaxy. To put this result into context, it is instructive to compare the
observed spatial distribution of novae in M83 with similar galaxies for which
nova populations have been studied. Such galaxies include the massive, late-
type, and nearly face-on spirals M51 and M101 (morphological types SA(s)bc and
SAB(rs)cd, respectively), the relatively low-mass, late-type systems NGC 2403
and M33 (SAB(s)cd and SA(s)cd, respectively), and M81, a relatively early-type
SA(s)ab spiral with a prominent bulge component. Unfortunately, as we explore
below, a review of these studies does not suggest a simple association between
the morphological type of the galaxy and the degree to which the nova
distribution follows the light of the host galaxy.

In the case of the face-on, grand-design spiral M101 (Shafter et al., 2000;
Coelho et al., 2008), the nova density appears to track the background light
remarkably well (K-S, p=0.94), while for M33 (Williams & Shafter, 2004;
Shafter et al., 2012), the cumulative distributions of the novae and the
background light were only marginally consistent (K-S, p=0.4). Similar to our
result for M83, the spatial distributions of novae in both M51 (Shafter et
al., 2000) and NGC 2403 (Franck et al., 2012), were also found to be more
spatially extended than the background light (with 97% and 75% confidence,
respectively). In theses cases, however, observational incompleteness in the
central region of M51 and the spiral arms of NGC 2403 could possibly explain
the discrepancy.

The situation with regard to M81 is more complex. The spatial distribution of
novae in this galaxy has been studied extensively by a number of groups, all
of whom have come to somewhat different conclusions about how the nova
distribution compares with the galaxy light. Based on a total of 15 and 12
detected novae, respectively, Moses & Shafter (1993) and Neill & Shara (2004)
argued that the M81 novae most closely follow the galaxy’s bulge light, as was
found in several studies of the nova population in M31 (Ciardullo et al.,
1987; Shafter et al., 2000; Darnley et al., 2006). More recently, however,
Hornoch et al. (2008) analyzed a much larger sample of novae (49) than either
of the previous studies, finding that the nova density distribution best
matches the overall (bulge + disk) background galaxy light. Given that M81 has
a prominent bulge component that dominates the overall light in regions where
most novae are found, the apparent discrepancy between these studies may be a
distinction without much of a difference. In reviewing the earlier studies in
more detail, it appears that neither the Moses & Shafter nor the Neill & Shara
data are inconsistent with the hypothesis that the novae follow the overall
light.

The only M81 nova study that reached a very different conclusion is that of
Shara et al. (1999), who analyzed a sample of 23 novae discovered nearly a
half century earlier on Palomar photographic plates taken between 1950 and
1955. They found a significant (disk) population of novae in the outer regions
of the galaxy that resulted in a poor fit of the full nova distribution to the
overall galaxy light (and clearly a worse fit to the bulge light). The poor
fit to the overall light persisted even after the authors attempted to correct
their data for missing novae in the inner bulge region of the galaxy. It is
not obvious how to reconcile these early photographic data with subsequent CCD
studies other than to posit that perhaps an even larger number of bulge novae
than expected were missed due to the difficulty in detecting them on
photographic plates when projected against the bright background of the
galaxy’s bulge.

Taken together, the best evidence currently available suggests that the nova
distribution in M81 likely follows the overall background light of the galaxy,
with novae belonging to both the bulge and disk populations. In the case of
most other galaxies, the situation remains less clear. A combination of small-
number statistics, spatial variations in extinction (especially in late-type
spiral galaxies), and limited spatial coverage (e.g., in M31) have all
conspired to make it difficult to differentiate a real spatial (stellar
population) variation from biases caused by observational incompleteness. As
is often the case, more data will be required before we have a full and
complete understanding of how the nova properties, including their specific
rates, vary with the underlying stellar population.

##  8 Summary

The principal results of our M83 nova survey are as follows:

(1) We have conducted an imaging survey of the SAB(s)c starburst galaxy M83
and discovered a total of 19 novae over the course of our seven-year survey.

(2) After correcting for the survey’s limiting magnitude and spatial and
temporal coverage, we find an overall nova rate of $R_{M83}=19^{+5}_{-3}$ yr-1
for the galaxy.

(3) Adopting an integrated $K$-band magnitude of $K_{M83}=4.62\pm 0.03$ from
the 2MASS survey, and a distance modulus for M83 of $(m-M)_{0}=28.34\pm 0.14$,
we find the absolute magnitude of M83 in the $K$-band is $M_{K}=-23.72$, which
corresponds to a luminosity of $6.32\times 10^{10}$ L⊙,K. The luminosity-
specific nova rate of M83 is then found to be $\nu_{K}=3.0^{+0.9}_{-0.6}\times
10^{-10}$ yr${}^{-1}~{}L_{\odot,K}^{-1}$.

(4) The value of $\nu_{K}$ for M83 is typical of those found for other
galaxies with measured nova rates, and, in agreement with our earlier studies,
no compelling evidence is found for a variation of $\nu_{K}$ with galaxy
color, or Hubble type.

(5) Our survey has enabled us to measure light curves for a total of 18 of the
19 novae discovered in M83. Of these, the peak brightnesses and fade rates
($t_{2}$ times) could be measured for 17 of the novae. These data show that
the most luminous novae we observed in M83 generally faded the fastest from
maximum light in accordance with the canonical MMRD relation.

(6) We have found the spatial distribution of novae in M83 to be more extended
than the background galaxy light suggesting that they are predominately
associated with the disk population of the galaxy. In addition, the M83 novae
appear, on average, to reach higher luminosities and to evolve more quickly
compared with novae in M31, which are predominately associated with that
galaxy’s bulge. These findings are consistent with the claim made by Duerbeck
(1990), Della Valle & Livio (1998), and others that there are two populations
of novae, a “disk” population characterized by generally brighter and faster
novae, and a “bulge” population, characterized by novae that are typically
slower and less luminous.

We thank the anonymous referee for their valuable comments and suggestions
that have helped us to improve the focus and presentation of this study. This
work is based on data collected with the Danish 1.54-m telescope at the ESO La
Silla Observatory. We thank J. Vraštil, E. Kortusová, L. Pilarčík, and V.
Votruba for acquiring some M83 images, J. L. Prieto for providing the M83
image taken with MEGACAM on the 6.5-m Magellan II telescope, and W. Burris for
assisting with the artificial nova tests used to assess the limiting magnitude
of our survey. The work of K.H., H.K., L.K., M.S., P.K., and P.Š. was
supported by the project RVO:67985815. The research of M.W. and P.Z. was
supported by the project Progres Q47 Physics of the Charles University in
Prague. M.S. acknowledges the support by Inter-transfer grant no LTT-20015.

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Table 1: Log of Observations UT Date | Julian Date | Limiting mag |
---|---|---|---
yr mon day | (2,450,000+) | ($R$) | NotesaaAll observations were made with the 1.54-m Danish Telescope at La Silla. The observers were: (1) K. Hornoch, (2) K. Hornoch and V. Votruba, (3) K. Hornoch and P. Kušnirák, (4) K. Hornoch and M. Wolf, (5) K. Hornoch and P. Zasche, (6) A. Galád, (7) L. Kotková, (8) P. Kušnirák, (9) K. Hornoch and P. Škoda, (10) P. Zasche, (11) M. Wolf, (12) M. Zejda, (13) K. Hornoch and M. Zejda, (14) K. Hornoch and A. Galád, (15) M. Skarka, (16) J. Liška, (17) V. Votruba, (18) J. Vraštil, (19) J. Janík, (20) J. Benáček, (21) E. Paunzen, (22) L. Pilarčík, (23) E. Kortusová, (24) E. Paunzen and M. Zejda, (25) M. Wolf and L. Pilarčík, (26) J. Juryšek, (27) H. Kučáková, (28) P. Kurfürst.
2012 12 12.361 | 6273.861 | 22.3 | 1
2012 12 18.368 | 6279.868 | 22.7 | 1
2012 12 22.352 | 6283.852 | 22.5 | 1
2012 12 23.345 | 6284.845 | 22.9 | 1
2012 12 28.314 | 6289.814 | 21.8 | 1
2013 01 02.313 | 6294.813 | 21.9 | 1
2013 01 08.374 | 6300.874 | 22.0 | 1
2013 01 09.370 | 6301.870 | 21.7 | 1
2013 01 10.374 | 6302.874 | 22.2 | 1
2013 01 11.367 | 6303.867 | 21.4 | 1
2013 01 12.374 | 6304.874 | 22.4 | 1
2013 01 14.384 | 6306.884 | 21.6 | 8
2013 01 15.389 | 6307.889 | 21.2 | 6
2013 01 17.368 | 6309.868 | 22.9 | 5
2013 01 18.360 | 6310.860 | 23.4 | 4
2013 01 19.387 | 6311.887 | 21.2 | 3
2013 01 22.373 | 6314.873 | 22.6 | 1
2013 01 23.387 | 6315.887 | 22.1 | 1
2013 01 26.382 | 6318.882 | 22.4 | 2
2013 01 28.389 | 6320.889 | 21.9 | 7
2013 01 29.378 | 6321.878 | 23.0 | 9
2013 01 31.362 | 6323.862 | 22.7 | 10
2013 02 01.308 | 6324.808 | 22.6 | 11
2013 02 03.327 | 6326.827 | 22.9 | 12
2013 02 05.390 | 6328.890 | 21.9 | 1
2013 02 07.397 | 6330.897 | 22.2 | 8
2013 02 08.395 | 6331.895 | 22.0 | 1
2013 02 09.381 | 6332.881 | 22.2 | 10
2013 02 11.387 | 6334.887 | 23.0 | 13
2013 02 12.389 | 6335.889 | 23.2 | 1
2013 02 13.397 | 6336.897 | 23.0 | 1
2013 02 14.398 | 6337.898 | 22.6 | 1
2013 02 16.396 | 6339.896 | 22.4 | 6
2013 02 18.388 | 6341.888 | 23.4 | 1
2013 02 19.385 | 6342.885 | 23.3 | 14
2013 02 20.405 | 6343.905 | 22.0 | 6
2013 02 22.362 | 6345.862 | 23.3 | 11
2013 02 24.349 | 6347.849 | 23.0 | 10
2013 02 25.386 | 6348.886 | 23.4 | 15
2013 03 01.338 | 6352.838 | 23.5 | 11
2013 03 04.397 | 6355.897 | 22.6 | 1
2013 03 06.401 | 6357.901 | 23.2 | 1
2013 03 08.404 | 6359.904 | 22.4 | 1
2013 03 09.404 | 6360.904 | 23.5 | 1
2013 03 14.244 | 6365.744 | 23.6 | 1
2013 03 24.377 | 6375.877 | 23.3 | 1
2012 04 01.240 | 6383.740 | 23.6 | 10
2013 04 05.364 | 6387.864 | 23.2 | 16
2013 04 06.249 | 6388.749 | 23.0 | 15
2013 04 07.301 | 6389.801 | 23.2 | 16
2013 04 08.360 | 6390.860 | 22.7 | 6
2013 04 09.125 | 6391.625 | 23.0 | 1
2013 04 11.422 | 6393.922 | 21.4 | 1
2013 04 16.420 | 6398.920 | 22.6 | 17
2013 04 17.104 | 6399.604 | 23.1 | 1
2013 12 14.349 | 6640.849 | 22.7 | 10
2013 12 15.317 | 6641.817 | 22.2 | 11
2013 12 21.343 | 6647.843 | 22.7 | 19
2013 12 30.367 | 6656.867 | 22.4 | 10
2013 12 31.368 | 6657.868 | 23.2 | 1
2014 01 03.369 | 6660.869 | 22.6 | 1
2014 01 04.369 | 6661.869 | 22.8 | 1
2014 01 08.372 | 6665.872 | 22.3 | 1
2014 01 20.356 | 6677.856 | 23.5 | 11
2014 01 28.379 | 6685.879 | 23.0 | 1
2014 01 29.373 | 6686.873 | 23.6 | 1
2014 01 30.373 | 6687.873 | 23.1 | 1
2014 02 01.368 | 6689.868 | 22.7 | 15
2014 02 02.298 | 6690.798 | 23.5 | 12
2014 02 03.344 | 6691.844 | 23.0 | 16
2014 02 04.391 | 6692.891 | 23.8 | 1
2014 02 05.371 | 6693.871 | 23.3 | 1
2014 02 06.394 | 6694.894 | 22.7 | 1
2014 02 07.399 | 6695.899 | 23.0 | 1
2014 02 08.395 | 6696.895 | 22.9 | 6
2014 02 09.400 | 6697.900 | 22.4 | 6
2014 02 11.346 | 6699.846 | 23.4 | 10
2014 02 12.352 | 6700.852 | 23.2 | 11
2014 02 13.232 | 6701.732 | 22.9 | 11
2014 02 14.311 | 6702.811 | 23.0 | 11
2014 02 16.302 | 6704.802 | 22.9 | 12
2014 02 17.338 | 6705.838 | 22.7 | 10
2014 02 18.322 | 6706.822 | 22.5 | 11
2014 02 20.377 | 6708.877 | 22.8 | 10
2014 02 22.328 | 6710.828 | 23.2 | 19
2014 02 27.261 | 6715.761 | 23.5 | 19
2014 02 28.407 | 6716.907 | 22.5 | 1
2014 03 01.408 | 6717.908 | 22.2 | 1
2014 03 02.407 | 6718.907 | 22.4 | 1
2014 03 03.407 | 6719.907 | 22.4 | 1
2014 03 04.404 | 6720.904 | 23.0 | 1
2014 03 05.409 | 6721.909 | 22.6 | 1
2014 03 07.413 | 6723.913 | 22.1 | 6
2014 03 08.411 | 6724.911 | 22.1 | 1
2014 03 10.319 | 6726.819 | 23.5 | 12
2014 03 11.221 | 6727.721 | 23.8 | 11
2014 03 16.407 | 6732.907 | 22.8 | 1
2014 03 21.057 | 6737.557 | 23.0 | 1
2014 03 22.242 | 6738.742 | 23.4 | 16
2014 03 24.208 | 6740.708 | 23.5 | 19
2014 03 26.331 | 6742.831 | 23.1 | 1
2014 03 29.420 | 6745.920 | 23.1 | 1
2014 04 06.122 | 6753.622 | 22.8 | 12
2014 04 07.161 | 6754.661 | 23.5 | 15
2014 04 10.183 | 6757.683 | 23.0 | 20
2014 12 24.327 | 7015.827 | 22.9 | 19
2014 12 25.355 | 7016.855 | 22.8 | 12
2014 12 27.344 | 7018.844 | 22.8 | 21
2015 01 02.346 | 7024.846 | 22.9 | 21
2015 01 09.351 | 7031.851 | 22.7 | 22
2015 01 10.362 | 7032.862 | 22.9 | 16
2015 01 11.352 | 7033.852 | 22.2 | 10
2015 01 12.345 | 7034.845 | 22.8 | 18
2015 01 13.339 | 7035.839 | 23.2 | 11
2015 01 15.379 | 7037.879 | 22.7 | 1
2015 01 16.375 | 7038.875 | 22.7 | 1
2015 01 19.381 | 7041.881 | 22.5 | 1
2015 01 20.383 | 7042.883 | 22.4 | 1
2015 01 22.349 | 7044.849 | 23.2 | 21
2015 01 25.388 | 7047.888 | 22.3 | 1
2015 01 27.390 | 7049.890 | 22.5 | 1
2015 01 28.374 | 7050.874 | 24.6 | 22
2015 01 31.375 | 7053.875 | 23.1 | 22
2015 02 01.307 | 7054.807 | 22.9 | 18
2015 02 03.376 | 7056.876 | 23.1 | 11
2015 02 04.304 | 7057.804 | 23.1 | 11
2015 02 06.375 | 7059.875 | 22.6 | 18
2015 02 10.329 | 7063.829 | 22.4 | 21
2015 02 12.394 | 7065.894 | 22.0 | 1
2015 02 13.394 | 7066.894 | 22.6 | 1
2015 02 14.396 | 7067.896 | 22.7 | 6
2015 02 17.402 | 7070.902 | 22.7 | 1
2015 02 18.402 | 7071.902 | 22.5 | 1
2015 02 22.378 | 7075.878 | 22.9 | 15
2015 03 03.342 | 7084.842 | 23.3 | 7
2015 03 05.288 | 7086.788 | 23.1 | 23
2015 03 12.407 | 7093.907 | 22.5 | 1
2015 03 13.414 | 7094.914 | 21.9 | 1
2015 03 14.412 | 7095.912 | 22.2 | 1
2015 03 17.413 | 7098.913 | 22.1 | 1
2015 03 19.416 | 7100.916 | 21.9 | 1
2015 03 20.409 | 7101.909 | 20.7 | 6
2015 03 28.422 | 7109.922 | 21.5 | 1
2015 03 31.328 | 7112.828 | 22.9 | 23
2015 04 01.321 | 7113.821 | 22.8 | 23
2015 04 08.415 | 7120.915 | 22.4 | 24
2015 12 15.366 | 7371.866 | 21.2 | 1
2015 12 26.319 | 7382.819 | 22.4 | 21
2016 01 02.322 | 7389.822 | 22.8 | 12
2016 01 11.374 | 7398.874 | 22.4 | 1
2016 01 12.371 | 7399.871 | 22.8 | 1
2016 01 18.365 | 7405.865 | 23.2 | 21
2016 02 01.391 | 7419.891 | 22.5 | 1
2016 02 16.381 | 7434.881 | 23.4 | 23
2016 02 18.391 | 7436.891 | 23.9 | 18
2016 02 19.398 | 7437.898 | 23.5 | 16
2016 02 22.387 | 7440.887 | 23.2 | 16
2016 02 24.406 | 7442.906 | 21.2 | 21
2016 02 25.361 | 7443.861 | 22.5 | 10
2016 02 28.401 | 7446.901 | 22.1 | 19
2016 03 02.216 | 7449.716 | 22.5 | 19
2016 03 03.384 | 7450.884 | 23.6 | 1
2016 03 04.409 | 7451.909 | 22.9 | 1
2016 03 06.395 | 7453.895 | 23.8 | 6
2016 03 09.410 | 7456.910 | 22.1 | 1
2016 03 11.401 | 7458.901 | 23.3 | 21
2016 03 15.415 | 7462.915 | 22.5 | 1
2016 03 17.164 | 7464.664 | 22.9 | 18
2016 03 18.408 | 7465.908 | 23.2 | 25
2016 03 26.120 | 7473.620 | 22.6 | 26
2016 03 31.408 | 7478.908 | 22.9 | 16
2017 12 23.363 | 8110.863 | 22.9 | 1
2018 01 28.263 | 8146.763 | 23.3 | 21
2018 01 29.278 | 8147.778 | 22.9 | 21
2018 01 30.244 | 8148.744 | 22.2 | 12
2018 02 03.360 | 8152.860 | 22.8 | 27
2018 02 06.220 | 8155.720 | 22.0 | 10
2018 02 07.259 | 8156.759 | 22.6 | 21
2018 02 15.397 | 8164.897 | 23.0 | 12
2018 02 26.233 | 8175.733 | 23.1 | 27
2018 02 27.208 | 8176.708 | 23.7 | 27
2018 02 28.200 | 8177.700 | 22.3 | 27
2018 03 13.395 | 8190.895 | 23.7 | 1
2018 03 15.415 | 8192.515 | 23.3 | 1
2018 03 17.409 | 8194.909 | 22.8 | 21
2018 03 19.417 | 8196.917 | 21.9 | 1
2018 03 22.417 | 8199.917 | 21.2 | 1
2018 03 26.207 | 8203.707 | 23.1 | 10
2018 03 28.415 | 8205.915 | 23.1 | 21
2019 01 12.372 | 8495.872 | 22.2 | 1
2019 01 30.388 | 8513.888 | 21.9 | 27
2019 02 04.394 | 8518.894 | 21.8 | 27
2019 02 06.394 | 8520.894 | 22.1 | 27
2019 02 18.399 | 8532.899 | 22.2 | 27
2019 02 19.401 | 8533.901 | 22.6 | 27
2019 03 01.406 | 8543.906 | 22.7 | 1
2019 03 02.282 | 8544.782 | 23.5 | 28
2019 03 04.404 | 8546.904 | 22.7 | 1
2019 03 05.405 | 8547.905 | 23.0 | 1
2019 03 06.405 | 8548.905 | 22.9 | 1
2019 03 10.386 | 8552.886 | 22.8 | 1
2019 03 12.387 | 8554.887 | 23.0 | 1
2019 03 13.406 | 8555.906 | 22.9 | 1
2019 03 14.363 | 8556.863 | 23.7 | 1
2019 03 21.245 | 8563.745 | 22.7 | 27

Table 3: M83 Nova Photometry (UT Date) | (JD - 2,450,000) | Mag | Unc. | Band
---|---|---|---|---
2013-nova1 = 2013-01a
2012 06 01.138 | 6079.638 | [22.6 | … | R
2012 12 12.361 | 6273.861 | [22.3 | … | R
2012 12 18.368 | 6279.868 | [22.7 | … | R
2012 12 23.345 | 6284.845 | [22.9 | … | R
2012 12 28.314 | 6289.814 | 21.0 | 0.15 | R
2012 12 28.316 | 6289.816 | 21.1 | 0.2 | I
2013 01 02.313 | 6294.813 | 21.6 | 0.2 | R
2013 01 08.374 | 6300.874 | 19.92 | 0.10 | R
2013 01 09.370 | 6301.870 | 19.90 | 0.10 | R
2013 01 10.374 | 6302.874 | 19.46 | 0.09 | R
2013 01 11.367 | 6303.867 | 19.46 | 0.10 | R
2013 01 12.374 | 6304.874 | 19.67 | 0.07 | R
2013 01 14.384 | 6306.884 | 20.4 | 0.1 | R
2013 01 15.389 | 6307.889 | 20.8 | 0.3 | R
2013 01 17.368 | 6309.868 | 21.1 | 0.15 | R
2013 01 18.360 | 6310.860 | 21.0 | 0.1 | R
2013 01 18.380 | 6310.880 | 20.9 | 0.2 | I
2013 01 19.387 | 6311.887 | 20.8 | 0.25 | R
2013 01 22.373 | 6314.873 | 21.3 | 0.15 | R
2013 01 23.387 | 6315.887 | 21.3 | 0.15 | R
2013 01 26.382 | 6318.882 | 21.7 | 0.2 | R
2013 01 28.389 | 6320.889 | 21.4 | 0.25 | R
2013 01 29.378 | 6321.878 | 21.8 | 0.2 | R
2013 01 29.392 | 6321.892 | 21.5 | 0.3 | I
2013 01 31.362 | 6323.862 | 22.2 | 0.2 | R
2013 02 01.308 | 6324.808 | 22.1 | 0.25 | R
2013 02 03.327 | 6326.827 | 22.3 | 0.3 | R
2013 02 05.390 | 6328.890 | 21.9 | 0.3 | R
2013 02 07.397 | 6330.897 | 22.2 | 0.35 | R
2013 02 08.395 | 6331.895 | 21.9 | 0.3 | R
2013 02 09.381 | 6332.881 | 22.2 | 0.3 | R
2013 02 11.387 | 6334.887 | 22.6 | 0.2 | R
2013 02 12.389 | 6335.889 | 22.7 | 0.25 | R
2013 02 13.397 | 6336.897 | 22.5 | 0.3 | R
2013 02 14.398 | 6337.898 | 22.6 | 0.25 | R
2013 02 16.396 | 6339.896 | 22.2 | 0.3 | R
2013 02 18.388 | 6341.888 | 22.9 | 0.3 | R
2013 02 19.385 | 6342.885 | 22.8 | 0.3 | R
2013 02 22.362 | 6345.862 | 22.9 | 0.25 | R
2013 02 24.349 | 6347.849 | 23.5 | 0.4 | R
2013 02 25.386 | 6348.886 | [23.4 | … | R
2013 03 01.338 | 6352.838 | [23.5 | … | R
2013-nova2 = 2013-01b
2012 06 01.138 | 6079.638 | [22.8 | … | R
2013 01 02.313 | 6294.813 | [22.7 | … | R
2013 01 08.374 | 6300.874 | 21.5 | 0.2 | R
2013 01 09.370 | 6301.870 | 21.2 | 0.2 | R
2013 01 10.374 | 6302.874 | 21.0 | 0.15 | R
2013 01 11.367 | 6303.867 | 21.1 | 0.3 | R
2013 01 12.374 | 6304.874 | 21.8 | 0.25 | R
2013 01 14.384 | 6306.884 | 21.5 | 0.3 | R
2013 01 18.360 | 6310.860 | 22.1 | 0.35 | R
2013 01 22.373 | 6314.873 | 22.6 | 0.35 | R
2013 01 26.382 | 6318.882 | 22.8 | 0.3 | R
2013 01 29.378 | 6321.878 | [23.0 | … | R
2013-nova3 = 2013-01c
2012 06 01.138 | 6079.638 | [22.8 | … | R
2012 12 28.314 | 6289.814 | [22.6 | … | R
2012 12 28.316 | 6289.816 | [22.2 | … | I
2013 01 02.313 | 6294.813 | 19.85 | 0.09 | R
2013 01 09.370 | 6301.870 | 21.0 | 0.15 | R
2013 01 10.374 | 6302.874 | 20.7 | 0.15 | R
2013 01 11.367 | 6303.867 | 20.7 | 0.2 | R
2013 01 12.374 | 6304.874 | 21.0 | 0.15 | R
2013 01 14.384 | 6306.884 | 21.3 | 0.25 | R
2013 01 17.368 | 6309.868 | 21.0 | 0.15 | R
2013 01 18.360 | 6310.860 | 21.2 | 0.15 | R
2013 01 19.387 | 6311.887 | 21.1 | 0.3 | R
2013 01 22.373 | 6314.873 | 21.4 | 0.2 | R
2013 01 23.387 | 6315.887 | 21.4 | 0.2 | R
2013 01 26.382 | 6318.882 | 21.6 | 0.2 | R
2013 01 28.389 | 6320.889 | 21.7 | 0.25 | R
2013 01 29.378 | 6321.878 | 21.7 | 0.2 | R
2013 01 29.392 | 6321.892 | 21.6 | 0.35 | I
2013 01 31.362 | 6323.862 | 22.1 | 0.4 | R
2013 02 01.308 | 6324.808 | 22.0 | 0.35 | R
2013 02 03.327 | 6326.827 | 22.0 | 0.35 | R
2013 02 05.390 | 6328.890 | 22.0 | 0.35 | R
2013 02 07.397 | 6330.897 | 21.8 | 0.3 | R
2013 02 08.395 | 6331.895 | 22.0 | 0.3 | R
2013 02 09.381 | 6332.881 | 21.7 | 0.3 | R
2013 02 11.387 | 6334.887 | 21.9 | 0.2 | R
2013 02 12.389 | 6335.889 | 21.9 | 0.2 | R
2013 02 13.397 | 6336.897 | 22.2 | 0.3 | R
2013 02 14.398 | 6337.898 | 22.3 | 0.3 | R
2013 02 16.396 | 6339.896 | 22.3 | 0.3 | R
2013 02 18.388 | 6341.888 | 22.2 | 0.3 | R
2013 02 19.385 | 6342.885 | 22.4 | 0.3 | R
2013 02 22.362 | 6345.862 | 22.5 | 0.25 | R
2013 02 24.349 | 6347.849 | 22.8 | 0.3 | R
2013 02 25.386 | 6348.886 | 22.4 | 0.25 | R
2013 03 01.338 | 6352.838 | 22.9 | 0.3 | R
2013 03 04.397 | 6355.897 | 22.2 | 0.3 | R
2013 03 06.401 | 6357.901 | 22.5 | 0.25 | R
2013 03 09.404 | 6360.904 | 23.5 | 0.4 | R
2013 03 14.244 | 6365.744 | 23.1 | 0.35 | R
2013 03 24.377 | 6375.877 | 22.7 | 0.3 | R
2013 04 06.249 | 6388.749 | 23.0 | 0.4 | R
2013 04 17.104 | 6399.604 | [23.3 | … | R
2013-nova4 = 2013-01d
2013 01 14.384 | 6306.884 | [21.9 | … | R
2013 01 15.389 | 6307.889 | [21.5 | … | R
2013 01 18.360 | 6310.860 | 22.5 | 0.25 | R
2013 01 18.380 | 6310.880 | [22.6 | … | I
2013 01 26.382 | 6318.882 | 21.2 | 0.1 | R
2013 01 29.378 | 6321.878 | 21.06 | 0.07 | R
2013 01 29.392 | 6321.892 | 20.8 | 0.15 | I
2013 01 31.362 | 6323.862 | 21.05 | 0.07 | R
2013 02 01.308 | 6324.808 | 20.91 | 0.08 | R
2013 02 03.327 | 6326.827 | 20.89 | 0.08 | R
2013 02 08.395 | 6331.895 | 20.92 | 0.10 | R
2013 02 11.387 | 6334.887 | 20.96 | 0.07 | R
2013 02 12.389 | 6335.889 | 21.15 | 0.08 | R
2013 02 13.397 | 6336.897 | 21.43 | 0.10 | R
2013 02 14.398 | 6337.898 | 21.2 | 0.1 | R
2013 02 18.388 | 6341.888 | 21.5 | 0.1 | R
2013 02 19.385 | 6342.885 | 21.7 | 0.15 | R
2013 02 25.386 | 6348.886 | 21.8 | 0.15 | R
2013 03 01.338 | 6352.838 | 22.0 | 0.1 | R
2013 03 02.288 | 6353.788 | 22.0 | 0.15 | I
2013 03 04.397 | 6355.897 | 21.8 | 0.15 | R
2013 03 06.401 | 6357.901 | 21.9 | 0.1 | R
2013 03 09.404 | 6360.904 | 22.3 | 0.15 | R
2013 03 24.377 | 6375.877 | 23.0 | 0.25 | R
2013 04 06.249 | 6388.749 | 22.8 | 0.2 | R
2013 04 17.104 | 6399.604 | 23.5 | 0.3 | R
2013 04 17.114 | 6399.614 | 22.7 | 0.4 | I
2013 12 14.349 | 6640.849 | [23.2 | … | R
2013-nova5 = 2013-04a
2012 06 01.138 | 6079.638 | [23.0 | … | R
2012 04 01.240 | 6383.740 | [23.6 | … | R
2013 04 05.364 | 6387.864 | 20.9 | 0.1 | R
2013 04 06.249 | 6388.749 | 20.20 | 0.06 | R
2013 04 07.301 | 6389.801 | 20.33 | 0.08 | R
2013 04 08.360 | 6390.860 | 20.25 | 0.09 | R
2013 04 09.125 | 6391.625 | 20.48 | 0.09 | R
2013 04 11.422 | 6393.922 | 21.1 | 0.25 | R
2013 04 16.420 | 6398.920 | 21.6 | 0.3 | R
2013 04 17.104 | 6399.604 | 21.5 | 0.2 | R
2013 04 17.114 | 6399.614 | 20.8 | 0.2 | I
2013 12 14.349 | 6640.849 | [22.7 | … | R
2013-nova6 = 2013-03a
2013 02 01.308 | 6324.808 | [23.4 | … | R
2013 02 03.327 | 6326.827 | [23.2 | … | R
2013 02 08.395 | 6331.895 | 22.2 | 0.3 | R
2013 02 11.387 | 6334.887 | 21.9 | 0.15 | R
2013 02 12.389 | 6335.889 | 22.1 | 0.15 | R
2013 02 13.397 | 6336.897 | 21.9 | 0.15 | R
2013 02 14.398 | 6337.898 | 21.8 | 0.15 | R
2013 02 18.388 | 6341.888 | 21.74 | 0.10 | R
2013 02 19.385 | 6342.885 | 21.67 | 0.09 | R
2013 02 22.362 | 6345.862 | 21.54 | 0.10 | R
2013 02 24.349 | 6347.849 | 21.7 | 0.15 | R
2013 02 25.386 | 6348.886 | 21.8 | 0.1 | R
2013 03 01.338 | 6352.838 | 21.72 | 0.09 | R
2013 03 02.288 | 6353.788 | 21.0 | 0.15 | I
2013 03 04.397 | 6355.897 | 21.7 | 0.15 | R
2013 03 06.401 | 6357.901 | 21.9 | 0.1 | R
2013 03 08.404 | 6359.904 | 21.9 | 0.25 | R
2013 03 09.404 | 6360.904 | 22.1 | 0.15 | R
2013 03 14.244 | 6365.744 | 21.9 | 0.1 | R
2013 03 14.413 | 6365.913 | 21.0 | 0.15 | I
2013 03 24.377 | 6375.877 | 21.9 | 0.1 | R
2012 04 01.240 | 6383.740 | 22.1 | 0.15 | R
2013 04 05.364 | 6387.864 | 22.4 | 0.2 | R
2013 04 06.249 | 6388.749 | 22.0 | 0.1 | R
2013 04 07.301 | 6389.801 | 22.6 | 0.2 | R
2013 04 08.360 | 6390.860 | 22.4 | 0.15 | R
2013 04 09.125 | 6391.625 | 22.3 | 0.2 | R
2013 04 16.420 | 6398.920 | 22.3 | 0.2 | R
2013 04 17.104 | 6399.604 | 22.4 | 0.15 | R
2013 04 17.114 | 6399.614 | 21.3 | 0.2 | I
2013 12 31.368 | 6657.868 | [23.2 | … | R
2014 03 11.221 | 6727.721 | [23.4 | … | R
2015 01 28.374 | 7050.874 | [23.8 | … | R
2016 02 18.391 | 7436.891 | [23.6 | … | R
2018 02 27.208 | 8176.708 | [23.7 | … | R
2019 03 14.363 | 8556.863 | [23.6 | … | R
2014-nova1 = 2014-01a
2014 01 09.371 | 6666.871 | [23.0 | … | R
2014 01 13.360 | 6670.860 | 19.60 | 0.15 | R
2014 01 16.271 | 6673.771 | 19.42 | 0.15 | R
2014 01 18.282 | 6675.782 | 20.0 | 0.15 | R
2014 01 20.356 | 6677.856 | 20.30 | 0.2 | R
2014 01 28.379 | 6685.879 | 22.1 | 0.25 | R
2014 01 29.373 | 6686.873 | 23.3 | 0.3 | R
2014 01 30.373 | 6687.873 | 22.8 | 0.35 | R
2014 02 01.368 | 6689.868 | 23.5 | 0.4 | R
2014 02 02.298 | 6690.798 | 24.3 | 0.5 | R
2014 02 02.307 | 6690.807 | [22.7 | … | I
2014 02 03.344 | 6691.844 | [22.7 | … | R
2014 02 04.391 | 6692.891 | [23.8 | … | R
2014-nova2 = 2014-01b
2014 01 20.356 | 6677.856 | [23.5 | … | R
2014 01 28.379 | 6685.879 | 21.7 | 0.15 | R
2014 01 29.373 | 6686.873 | 21.9 | 0.15 | R
2014 01 30.373 | 6687.873 | 22.1 | 0.15 | R
2014 02 01.368 | 6689.868 | 22.0 | 0.15 | R
2014 02 02.298 | 6690.798 | 21.9 | 0.15 | R
2014 02 02.307 | 6690.807 | 21.8 | 0.2 | I
2014 02 03.344 | 6691.844 | 21.7 | 0.2 | R
2014 02 04.391 | 6692.891 | 21.5 | 0.15 | R
2014 02 05.371 | 6693.871 | 21.2 | 0.15 | R
2014 02 06.394 | 6694.894 | 22.2 | 0.2 | R
2014 02 07.399 | 6695.899 | 23.0 | 0.4 | R
2014 02 08.395 | 6696.895 | 22.8 | 0.4 | R
2014 02 09.400 | 6697.900 | 22.4 | 0.5 | R
2014 02 11.346 | 6699.846 | 22.7 | 0.25 | R
2014 02 12.352 | 6700.852 | 22.5 | 0.25 | R
2014 02 13.232 | 6701.732 | 22.1 | 0.25 | R
2014 02 14.311 | 6702.811 | 22.3 | 0.3 | R
2014 02 16.302 | 6704.802 | 22.1 | 0.3 | R
2014 02 17.338 | 6705.838 | 21.9 | 0.35 | R
2014 02 18.322 | 6706.822 | 21.7 | 0.35 | R
2014 02 20.377 | 6708.877 | 22.1 | 0.25 | R
2014 02 22.328 | 6710.828 | 22.7 | 0.3 | R
2014 02 27.261 | 6715.761 | 22.5 | 0.3 | R
2014 02 28.407 | 6716.907 | 22.1 | 0.5 | R
2014 03 01.408 | 6717.908 | [22.3 | … | R
2014 03 02.407 | 6718.907 | 22.7 | 0.4 | R
2014 03 03.407 | 6719.907 | 22.6 | 0.4 | R
2014 03 04.404 | 6720.904 | 22.9 | 0.4 | R
2014 03 05.409 | 6721.909 | 22.9 | 0.4 | R
2014 03 07.413 | 6723.913 | [22.1 | … | R
2014 03 08.411 | 6724.911 | [22.1 | … | R
2014 03 10.319 | 6726.819 | 24.1 | 0.4 | R
2014 03 11.221 | 6727.721 | 23.3 | 0.4 | R
2014 03 16.407 | 6732.907 | [22.8 | … | R
2014 03 21.057 | 6737.557 | [23.0 | … | R
2014 03 22.242 | 6738.742 | [23.8 | … | R
2014 03 24.208 | 6740.708 | 23.8 | 0.4 | R
2014 03 26.331 | 6742.831 | [23.1 | … | R
2014 03 29.420 | 6745.920 | [23.1 | … | R
2014 04 06.122 | 6753.622 | [22.8 | … | R
2014 04 07.161 | 6754.661 | [23.5 | … | R
2014 04 10.183 | 6757.683 | [23.0 | … | R
2014-nova3 = 2014-01c
2014 01 20.356 | 6677.856 | [23.4 | … | R
2014 01 28.379 | 6685.879 | 22.7 | 0.4 | R
2014 01 29.373 | 6686.873 | 22.0 | 0.2 | R
2014 01 30.373 | 6687.873 | 20.9 | 0.15 | R
2014 02 01.368 | 6689.868 | 19.4 | 0.1 | R
2014 02 02.298 | 6690.798 | 18.94 | 0.07 | R
2014 02 02.307 | 6690.807 | 18.7 | 0.15 | I
2014 02 03.344 | 6691.844 | 18.89 | 0.07 | R
2014 02 04.391 | 6692.891 | 19.1 | 0.1 | R
2014 02 05.371 | 6693.871 | 19.3 | 0.1 | R
2014 02 06.394 | 6694.894 | 20.15 | 0.1 | R
2014 02 07.399 | 6695.899 | 20.6 | 0.15 | R
2014 02 08.395 | 6696.895 | 21.1 | 0.15 | R
2014 02 09.400 | 6697.900 | 21.4 | 0.2 | R
2014 02 11.346 | 6699.846 | 21.6 | 0.15 | R
2014 02 12.352 | 6700.852 | 21.7 | 0.2 | R
2014 02 13.232 | 6701.732 | 21.5 | 0.25 | R
2014 02 14.311 | 6702.811 | 21.5 | 0.25 | R
2014 02 16.302 | 6704.802 | 21.6 | 0.3 | R
2014 02 17.338 | 6705.838 | 22.0 | 0.35 | R
2014 02 18.322 | 6706.822 | 21.8 | 0.35 | R
2014 02 20.377 | 6708.877 | 21.9 | 0.3 | R
2014 02 22.328 | 6710.828 | 22.1 | 0.3 | R
2014 02 27.261 | 6715.761 | 22.4 | 0.4 | R
2014 02 28.407 | 6716.907 | 22.1 | 0.4 | R
2014 03 01.408 | 6717.908 | [22.2 | … | R
2014 03 02.407 | 6718.907 | 22.3 | 0.4 | R
2014 03 03.407 | 6719.907 | 21.9 | 0.4 | R
2014 03 04.404 | 6720.904 | 22.5 | 0.4 | R
2014 03 05.409 | 6721.909 | 22.1 | 0.4 | R
2014 03 07.413 | 6723.913 | [22.1 | … | R
2014 03 08.411 | 6724.911 | [22.1 | … | R
2014 03 10.319 | 6726.819 | 22.9 | 0.35 | R
2014 03 11.221 | 6727.721 | 23.0 | 0.4 | R
2014 03 16.407 | 6732.907 | [22.8 | … | R
2014 03 21.057 | 6737.557 | [23.0 | … | R
2014 03 22.242 | 6738.742 | 23.2 | 0.4 | R
2014 03 24.208 | 6740.708 | 22.9 | 0.4 | R
2014 03 26.331 | 6742.831 | [23.1 | … | R
2014 03 29.420 | 6745.920 | [22.6 | … | R
2014 04 06.122 | 6753.622 | [22.0 | … | R
2014 04 07.161 | 6754.661 | [23.0 | … | R
2014 04 10.183 | 6757.683 | [23.0 | … | R
2014-nova4 = 2014-03a
2014 03 03.407 | 6719.907 | [23.2 | … | R
2014 03 04.404 | 6720.904 | 21.2 | 0.25 | R
2014 03 05.409 | 6721.909 | 19.75 | 0.10 | R
2014 03 07.413 | 6723.913 | 19.8 | 0.1 | R
2014 03 08.411 | 6724.911 | 19.95 | 0.1 | R
2014 03 10.319 | 6726.819 | 20.06 | 0.08 | R
2014 03 11.221 | 6727.721 | 20.5 | 0.1 | R
2014 03 16.407 | 6732.907 | 22.7 | 0.4 | R
2014 03 21.057 | 6737.557 | 23.0 | 0.4 | R
2014 03 22.242 | 6738.742 | 22.9 | 0.35 | R
2014 03 24.208 | 6740.708 | 22.7 | 0.3 | R
2014 03 26.331 | 6742.831 | [23.1 | … | R
2014 03 29.420 | 6745.920 | [23.2 | … | R
2014 04 06.122 | 6753.622 | [23.1 | … | R
2014 04 07.161 | 6754.661 | [23.0 | … | R
2014 04 10.183 | 6757.683 | [22.4 | … | R
2015-nova1 = 2015-01a
2014 12 27.344 | 7018.844 | [23.3 | … | R
2015 01 02.346 | 7024.846 | 22.5 | 0.1 | R
2015 01 09.351 | 7031.851 | 20.69 | 0.08 | R
2015 01 10.362 | 7032.862 | 20.82 | 0.09 | R
2015 01 11.352 | 7033.852 | 20.7 | 0.1 | R
2015 01 11.354 | 7033.854 | 20.4 | 0.15 | I
2015 01 12.345 | 7034.845 | 20.73 | 0.05 | R
2015 01 13.339 | 7035.839 | 21.15 | 0.06 | R
2015 01 15.379 | 7037.879 | 21.04 | 0.08 | R
2015 01 16.375 | 7038.875 | 21.30 | 0.09 | R
2015 01 19.381 | 7041.881 | 21.55 | 0.12 | R
2015 01 20.383 | 7042.883 | 21.8 | 0.15 | R
2015 01 22.349 | 7044.849 | 21.72 | 0.08 | R
2015 01 25.388 | 7047.888 | 21.8 | 0.15 | R
2015 01 27.390 | 7049.890 | 22.4 | 0.25 | R
2015 01 28.374 | 7050.874 | 22.35 | 0.09 | R
2015 01 31.375 | 7053.875 | 22.3 | 0.15 | R
2015 02 01.307 | 7054.807 | 22.6 | 0.2 | R
2015 02 03.376 | 7056.876 | 22.6 | 0.2 | R
2015 02 04.304 | 7057.804 | 23.0 | 0.35 | R
2015 02 06.375 | 7059.875 | [22.6 | … | R
2015-nova2 = 2015-04a
2015 04 01.321 | 7113.821 | [22.8 | … | R
2015 04 08.415 | 7120.915 | 21.4 | 0.25 | R
2016-nova1 = 2016-02a
2016 02 18.391 | 7436.891 | [23.7 | … | R
2016 02 19.398 | 7437.898 | 22.9 | 0.35 | R
2016 02 22.387 | 7440.887 | 21.14 | 0.09 | R
2016 02 24.406 | 7442.906 | 21.0 | 0.2 | R
2016 02 25.361 | 7443.861 | 20.84 | 0.10 | R
2016 02 28.401 | 7446.901 | 20.8 | 0.15 | R
2016 03 02.216 | 7449.716 | 21.4 | 0.15 | R
2016 03 03.384 | 7450.884 | 21.44 | 0.10 | R
2016 03 03.401 | 7450.901 | 21.5 | 0.25 | I
2016 03 04.409 | 7451.909 | 21.4 | 0.15 | R
2016 03 06.395 | 7453.895 | 21.53 | 0.09 | R
2016 03 09.410 | 7456.910 | 21.6 | 0.25 | R
2016 03 11.401 | 7458.901 | 22.1 | 0.2 | R
2016 03 17.164 | 7464.664 | 22.2 | 0.25 | R
2016 03 18.408 | 7465.908 | 22.4 | 0.2 | R
2016 03 26.120 | 7473.620 | [22.6 | … | R
2016 03 31.408 | 7478.908 | [22.9 | … | R
2016-nova2 = 2016-02b
2016 02 18.391 | 7436.891 | [24.0 | … | R
2016 02 19.398 | 7437.898 | [23.5 | … | R
2016 02 22.387 | 7440.887 | 21.42 | 0.09 | R
2016 02 24.406 | 7442.906 | 21.1 | 0.2 | R
2016 02 25.361 | 7443.861 | 20.55 | 0.10 | R
2016 02 28.401 | 7446.901 | 20.4 | 0.15 | R
2016 03 02.216 | 7449.716 | 21.1 | 0.15 | R
2016 03 03.384 | 7450.884 | 21.17 | 0.09 | R
2016 03 03.401 | 7450.901 | 20.6 | 0.1 | I
2016 03 04.409 | 7451.909 | 21.4 | 0.15 | R
2016 03 06.395 | 7453.895 | 21.4 | 0.1 | R
2016 03 09.410 | 7456.910 | 21.7 | 0.25 | R
2016 03 11.401 | 7458.901 | 21.6 | 0.15 | R
2016 03 17.164 | 7464.664 | 21.8 | 0.15 | R
2016 03 18.408 | 7465.908 | 22.0 | 0.15 | R
2016 03 26.120 | 7473.620 | 21.8 | 0.3 | R
2016 03 31.408 | 7478.908 | 22.4 | 0.3 | R
2016-nova3 = 2016-03a
2016 03 15.415 | 7462.915 | [22.5 | … | R
2016 03 17.164 | 7464.664 | 20.60 | 0.09 | R
2016 03 18.408 | 7465.908 | 19.87 | 0.08 | R
2016 03 26.120 | 7473.620 | 21.2 | 0.1 | R
2016 03 31.408 | 7478.908 | 21.7 | 0.2 | R
2018-nova1 = 2018-01a
2017 12 23.363 | 8110.863 | [22.9 | … | R
2018 01 28.263 | 8146.763 | 20.71 | 0.08 | R
2018 01 29.278 | 8147.778 | 20.86 | 0.09 | R
2018 01 29.290 | 8147.790 | 20.7 | 0.1 | I
2018 01 30.244 | 8148.744 | 21.3 | 0.1 | R
2018 02 03.360 | 8152.860 | 21.4 | 0.1 | R
2018 02 06.220 | 8155.720 | 21.4 | 0.3 | R
2018 02 07.259 | 8156.759 | 21.7 | 0.15 | R
2018 02 15.397 | 8164.897 | 22.1 | 0.25 | R
2018 02 26.233 | 8175.733 | 22.8 | 0.3 | R
2018 02 27.208 | 8176.708 | 22.9 | 0.3 | R
2018 02 28.200 | 8177.700 | 22.5 | 0.3 | R
2018 03 13.395 | 8190.895 | [23.1 | … | R
2018 03 17.409 | 8194.909 | [23.1 | … | R
2018-nova2 = 2018-02a
2018 02 15.397 | 8164.897 | [23.2 | … | R
2018 02 26.233 | 8175.733 | 21.5 | 0.15 | R
2018 02 27.208 | 8176.708 | 21.6 | 0.15 | R
2018 02 28.200 | 8177.700 | 21.3 | 0.25 | R
2018 03 13.395 | 8190.895 | 22.0 | 0.2 | R
2018 03 15.415 | 8192.915 | 21.4 | 0.3 | R
2018 03 17.409 | 8194.909 | 21.8 | 0.25 | R
2018 03 19.417 | 8196.917 | 21.6 | 0.25 | R
2018 03 21.417 | 8198.917 | 18.5 | 0.2 | Ha
2018 03 26.207 | 8203.707 | 22.4 | 0.2 | R
2018 03 28.415 | 8205.915 | 22.4 | 0.5 | R
2019-nova1 = 2019-02a
2019 02 06.394 | 8520.894 | [22.1 | … | R
2019 02 18.399 | 8532.899 | 19.9 | 0.1 | R
2019 02 19.401 | 8533.901 | 20.1 | 0.15 | R
2019 03 01.406 | 8543.906 | 22.5 | 0.4 | R
2019 03 02.282 | 8544.782 | 22.1 | 0.4 | R
2019 03 05.405 | 8547.905 | 22.4 | 0.4 | R
2019 03 06.405 | 8548.905 | 22.6 | 0.4 | R
2019 03 08.403 | 8550.903 | 21.9 | 0.3 | I
2019-nova2 = 2019-03a
2018 03 26.207 | 8203.707 | [24.0 | … | R
2019 02 06.394 | 8520.894 | [22.7 | … | R
2019 02 18.399 | 8532.899 | 22.0 | 0.4 | R
2019 03 01.406 | 8543.906 | 22.2 | 0.4 | R
2019 03 02.282 | 8544.782 | 22.0 | 0.2 | R
2019 03 04.404 | 8546.904 | 21.9 | 0.25 | R
2019 03 05.405 | 8547.905 | 22.2 | 0.3 | R
2019 03 06.405 | 8548.905 | 22.0 | 0.3 | R
2019 03 08.403 | 8550.903 | 21.9 | 0.3 | I
2019 03 10.386 | 8552.886 | 22.1 | 0.25 | R
2019 03 12.387 | 8554.887 | 21.64 | 0.09 | R
2019 03 13.406 | 8555.906 | 21.65 | 0.09 | R
2019 03 14.363 | 8556.863 | 21.56 | 0.08 | R
2019 03 21.245 | 8563.745 | 21.9 | 0.1 | R
Probable SN in anonymous galaxy in the field of M83
2012 06 01.138 | 6079.638 | [22.8 | … | R
2013 01 12.374 | 6304.874 | [22.5 | … | R
2013 01 17.368 | 6309.868 | 21.9 | 0.25 | R
2013 01 18.360 | 6310.860 | 21.6 | 0.2 | R
2013 01 18.380 | 6310.880 | 21.6 | 0.3 | I
2013 01 19.387 | 6311.887 | 21.2 | 0.3 | R
2013 01 22.373 | 6314.873 | 21.3 | 0.15 | R
2013 01 23.387 | 6315.887 | 21.3 | 0.15 | R
2013 01 26.382 | 6318.882 | 21.1 | 0.15 | R
2013 01 28.389 | 6320.889 | 20.9 | 0.2 | R
2013 01 29.378 | 6321.878 | 20.9 | 0.15 | R
2013 01 29.392 | 6321.892 | 20.5 | 0.15 | I
2013 01 31.362 | 6323.862 | 21.0 | 0.1 | R
2013 02 01.308 | 6324.808 | 20.9 | 0.15 | R
2013 02 03.327 | 6326.827 | 21.0 | 0.1 | R
2013 02 05.390 | 6328.890 | 20.8 | 0.25 | R
2013 02 07.397 | 6330.897 | 21.5 | 0.3 | R
2013 02 08.395 | 6331.895 | 21.5 | 0.3 | R
2013 02 09.381 | 6332.881 | 21.0 | 0.35 | R
2013 02 11.387 | 6334.887 | 21.2 | 0.15 | R
2013 02 12.389 | 6335.889 | 21.3 | 0.1 | R
2013 02 13.397 | 6336.897 | 21.4 | 0.15 | R
2013 02 14.398 | 6337.898 | 21.3 | 0.15 | R
2013 02 16.396 | 6339.896 | 21.5 | 0.2 | R
2013 02 18.388 | 6341.888 | 21.6 | 0.2 | R
2013 02 19.385 | 6342.885 | 21.7 | 0.2 | R
2013 02 20.404 | 6343.904 | 21.8 | 0.3 | R
2013 02 22.362 | 6345.862 | 21.7 | 0.1 | R
2013 02 24.349 | 6347.849 | 21.8 | 0.15 | R
2013 02 25.386 | 6348.886 | 22.0 | 0.15 | R
2013 03 01.338 | 6352.838 | 22.1 | 0.15 | R
2013 03 02.288 | 6353.788 | 21.4 | 0.15 | R
2013 03 04.397 | 6355.897 | 22.3 | 0.2 | R
2013 03 06.401 | 6357.901 | 22.1 | 0.2 | R
2013 03 09.404 | 6360.904 | 22.4 | 0.2 | R
2013 03 14.244 | 6365.744 | 22.6 | 0.25 | R
2013 03 24.377 | 6375.877 | 22.8 | 0.3 | R
2013 04 06.249 | 6388.749 | 22.6 | 0.4 | R
2013 04 07.301 | 6389.801 | 23.0 | 0.4 | R
2013 04 08.360 | 6390.860 | 22.7 | 0.35 | R