Spectroscopic classification of AT2021niy as a dwarf nova in outburst
ATel #14823; Ann Isaacs (UMN), Patrick Kelly (UMN), Peter Garnavich (Notre Dame), Paul Smith (Steward Observatory, University of Arizona)
on 1 Aug 2021; 14:54 UT
Credential Certification: Patrick Kelly (plkelly@umn.edu)
We report the spectral classification of transient AT2021niy. The transient was identified by ATLAS on 2021-05-24. Observations were made on UT 2021-06-06 with Steward Observatory's Bok telescope on Kitt Peak, Arizona. We obtained three exposures lasting 900 seconds each using the Boller & Chivens spectrograph. The slit width was 2.5 arcseconds and the spectral coverage ranged from 3700 to 8000 angstroms. The data were then reduced using PypeIt (Prochaska et al., 2020).
This object shows a continuum spectrum that peaks near 4200 Angstroms with Balmer lines close to zero redshift. The spectrum is consistent with that of a dwarf nova in outburst. We located a likely progenitor in SDSS consistent with a point source and that is brightest in the g band with a magnitude of 20.68. It is notably blue in color.
