Spectroscopic classification of the transient ZTF21abjiotr/AT2021scd
ATel #14784; Monika Soraisam (NCSA/UIUC), Chien-Hsiu Lee (NOIRLab), Gautham Narayan (UIUC), Thomas Matheson, Abhijit Saha (NOIRLab), Thomas G. Brink, Kishore C. Patra, WeiKang Zheng, Alexei V. Filippenko (UC Berkeley)
on 13 Jul 2021; 22:11 UT
Credential Certification: Monika Soraisam (soraisam@illinois.edu)
Subjects: Optical, Nova, Transient
We report the spectroscopic observation of ZTF21abjiotr/AT2021scd (RA 0h42m17.93s, Dec +41d00m18.55s; J2000). The source was flagged as a transient associated with M31 from the ZTF public alert stream by the ANTARES alert-broker (https://antares.noirlab.edu/loci/ANT2021r73a2).
On 2021 Jul 10 UT, we obtained the spectrum of this source with the Kast double spectrograph on the Shane 3 m telescope at Lick Observatory. The spectrum shows Balmer emission lines with the FWHM of the H-alpha line around 1600 km/s, as well as emission lines of O I, Fe II, Ca II, and the Paschen series between 8500 and 9500 Å. The lines are blue-shifted with radial velocity (based on H-alpha) around -300 km/s, similar to the systemic velocity of M31's center of mass. Overall, the spectrum is thus consistent with a nova in M31.
