through the advanced Public ESO Spectroscopy Survey of Transient Objects (ePESSTO+; @Smartt2015); the LCO 2-m North and South telescopes with FLOYDS; the 2-m Liverpool Telescope (LT) with SPRAT [@Piascik2014] in the blue-optimised setting, as part of C-SNAILS [@Nicholl2019csnails]; the 6.5-m MMT telescope with Binospec [@Fabricant2019]; the 6.5-m Magellan Clay telescope with LDSS-3 and the VPH-ALL grism; the 4.2-m William Herschel Telescope with ISIS [@Jorden1990] and the R600 blue/red gratings; and the 8-m ESO Very Large Telescope using X-Shooter [@Vernet2011] in on-slit nodding mode, through our TDE target-of-opportunity program.

Reduction and extraction of these data were performed using instrument-specific pipelines or (in the cases of the LDSS-3 and ISIS data) standard routines in <span style="font-variant:small-caps;">iraf</span>. Reduced LCO and LT data were downloaded from the respective data archives, while we ran the pipelines [@Smartt2015; @Freudling2013] locally for the EFOSC2 and X-Shooter data[^7]. Typical reduction steps are de-biasing, flat-fielding and wavelength-calibration using standard lamps, cosmic-ray removal [@vanDokkum2012], flux calibration using spectra of standard stars obtained with the same instrument setups, and variance-weighted extraction to a one-dimensional spectrum. We also retrieved the reduced classification spectrum obtained by @Siebert2019 using the 10-m Keck-I telescope with LRIS [@Oke1995], and made public via the Transient Name Server[^8]. 