Spectral classification of the AT2020abjr near M31 galaxy
ATel #14269; A. F. Valeev; A. Vinokurov; S. Fabrika; N. V. Borisov; A. A. Grokhovskay; Yu. Solovyeva (SAO RAS)
on 16 Dec 2020; 20:17 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Sergei Fabrika (fabrika@sao.ru)
Subjects: Optical, Nova, Transient
Following the detection of AT2020abjr (ATLAS20bgko/ZTF18abxzyss) near M31 galaxy, we obtained optical spectra and images using the SCORPIO2 spectrograph mounted on the prime focus of BTA 6-m telescope. Using the 1 arcsec slit the 3800 - 7300 ÅÅ waverange with spectral resolution ~5 Å was covered.
The transient photometry at 2020-12-13 15:20 UT reveals B = 19.62 ± 0.15, V = 19.55 ± 0.05, R = 19.67 ± 0.07.
The object was undetectable on the archive PanSTARRS images with the upper limit magnitude r ~ 23.6 mag. Its brightness increased more than 5 magnitudes (r = 18.56 at 2020-12-03 03:50 according to the ZTF measurement) and is slowly decreasing ~ 0.1 mag/day (r = 19.6 ± 0.1 at 2020-12-13 15:20 using transformation of our measurement from Jonhson to SDSS using Jester et al. (2005) equations).
The spectrum reveals the broad absorption lines of Hδ, Hγ and Hβ. We clearly see the complex Hβ profile: the broad absorption with the sharp emission. The only sharp emission component is visible on the Hα profile (FWHM = 9 Å value was corrected for spectral resolution).
We make the conclusion that the object belongs to dwarf novae in Galaxy.
