Universe Guide

30 Comae Berenices

30 Comae Berenices Facts

30 Comae Berenices's Alternative Names

The Id of the star in the Yale Bright Star Catalogue is HR4869. HIP62576 is the reference name for the star in the Hipparcos Star Catalogue. The Id of the star in the Henry Draper catalogue is HD111469.

Flamsteed designations are named after the creator, Sir John Flamsteed. Sir John numbered the stars in the constellation with a number and the latin name, this star's Flamsteed designation is 30 Comae Berenices with it shortened to 30 Com.



Location of 30 Comae Berenices


Radial Velocity and Proper Motion of 30 Comae Berenices

Proper Motion

All stars like planets orbit round a central spot, in the case of planets, its the central star such as the Sun. In the case of a star, its the galactic centre. The constellations that we see today will be different than they were 50,000 years ago or 50,000 years from now. Proper Motion details the movements of these stars and are measured in milliarcseconds. The star is moving 22.56 ± 0.22 milliarcseconds/year towards the north and -91.60 ± 0.32 milliarcseconds/year east if we saw them in the horizon.

Radial Velocity

The Radial Velocity, that is the speed at which the star is moving away/towards the Sun is -11.00 km/s with an error of about 2.30 km/s . When the value is negative then the star and the Sun are getting closer to one another, likewise, a positive number means that two stars are moving away. Its nothing to fear as the stars are so far apart, they won't collide in our life-time, if ever.

30 Comae Berenices Luminosity

Luminosity is the amount of energy that a star pumps out and its relative to the amount that our star, the Sun gives out. The figure of 38.32 that I have given is based on the value in the Simbad Hipparcos Extended Catalogue at the University of Strasbourg from 2012.

Physical Properties (Colour, Temperature) of 30 Comae Berenices

30 Comae Berenices Colour and Temperature

30 Comae Berenices has a spectral type of A2V. This means the star is a blue - white main sequence star. The star has a B-V Colour Index of 0.05 which means the star's temperature has been calculated using information from Morgans @ Uni.edu at being 8,917 Kelvin.

30 Comae Berenices Radius

Radius has been calculated as being 2.77 times bigger than the Sun. The Sun's radius is 695,800km, therefore the star's radius is an estimated 1,927,271.65.km. If you need the diameter of the star, you just need to multiple the radius by 2. However with the 2007 release of updated Hipparcos files, the radius is now calculated at being round 2.56. The figure is derived at by using the formula from SDSS and has been known to produce widely incorrect figures.

30 Comae Berenices Apparent and Absolute Magnitudes

30 Comae Berenices has an apparent magnitude of 5.76 which is how bright we see the star from Earth. Apparent Magnitude is also known as Visual Magnitude. If you used the 1997 Parallax value, you would get an absolute magnitude of 0.75 If you used the 2007 Parallax value, you would get an absolute magnitude of 0.92. Magnitude, whether it be apparent/visual or absolute magnitude is measured by a number, the smaller the number, the brighter the Star is. Our own Sun is the brightest star and therefore has the lowest of all magnitudes, -26.74. A faint star will have a high number.

Distance to 30 Comae Berenices

Using the original Hipparcos data that was released in 1997, the parallax to the star was given as 9.97 which gave the calculated distance to 30 Comae Berenices as 327.14 light years away from Earth or 100.30 parsecs. It would take a spaceship travelling at the speed of light, 327.14 years to get there. We don't have the technology or spaceship that can carry people over that distance yet.

In 2007, Hipparcos data was revised with a new parallax of 10.76 which put 30 Comae Berenices at a distance of 303.13 light years or 92.94 parsecs. It should not be taken as though the star is moving closer or further away from us. It is purely that the distance was recalculated.

Using the 2007 distance, the star is roughly 19,170,117.51 Astronomical Units from the Earth/Sun give or take a few. An Astronomical Unit is the distance between Earth and the Sun. The number of A.U. is the number of times that the star is from the Earth compared to the Sun.


Source of Information


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Additional 30 Comae Berenices Facts and Figures

Visual Facts

Primary / Proper / Traditional Name30 Comae Berenices
Alternative NamesHD 111469, HIP 62576, HR 4869, 30 Com, BD+28 2153
Spectral TypeA2V
Constellation's Main StarNo
Multiple Star SystemYes
Star Type Main Sequence Dwarf Star
GalaxyMilky Way
ConstellationComa Berenices
Absolute Magnitude 0.75 / 0.92
Visual / Apparent Magnitude5.76
Naked Eye VisibleYes - Magnitudes
Right Ascension (R.A.)12h 49m 17.51
Declination (Dec.)+27° 33` 08.4
Galactic Latitude89.36 degrees
Galactic Longitude171.15 degrees
1997 Distance from Earth9.97 Parallax (milliarcseconds)
 327.14 Light Years
 100.30 Parsecs
2007 Distance from Earth10.76 Parallax (milliarcseconds)
 303.13 Light Years
 92.94 Parsecs
 19,170,117.51 Astronomical Units
Galacto-Centric Distance24,142.61 Light Years / 7,402.00 Parsecs
Proper Motion Dec.22.56 ± 0.22 milliarcseconds/year
Proper Motion RA.-91.60 ± 0.32 milliarcseconds/year
B-V Index0.05
Radial Velocity-11.00 ± 2.30 km/s
Semi-Major Axis7511.00
Stellar Luminosity (Lsun)38.32

Companions (Multi-Star and Exoplanets) Facts

Exoplanet CountNone/Unaware

Estimated Calculated Facts

Radius (x the Sun)2.56
Effective Temperature8,917 Kelvin

Sources and Links

SIMBAD SourceLink

Multi-Star System


Proper Motion mas/yr
H.D. IdB.D. IdStar CodeMagnitudeR.A.Dec.SpectrumColourYear
111469+28 2153.0A5.80000-98.0000017.00000A0White

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