Spectroscopic Classifications of Optical Transients with the Lick Shane telescope
ATel #14546; K. Taggart, C. Rojas-Bravo, R. J. Foley (UCSC), C. R. Angus (DARK)
on 13 Apr 2021; 20:48 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Kirsty Taggart (k.taggart@ucsc.edu)
Subjects: Optical, Supernovae
We report the following classifications of optical transients from spectroscopic observations with the Kast spectrograph on the Shane telescope. The targets were supplied by ALeRCE and Fink (selected from the ZTF data stream) and ATLAS. All Observations were made on 2021 Apr 13 UT. Classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).
Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes
ZTF21aasuego | AT2021inl | 13:01:33.245 | +27:49:55.12 | 0.02 |Ib-pec| +10 | (1)
ZTF19aagthvg | AT2021ita | 12:25:58.821 | +07:14:07.09 | 0.154 | Ia | -2 | (2)
ZTF18aatjfoe | AT2021itd | 14:44:51.079 | +43:19:00.54 | 0.081 | Ia | -4 | (3)
ATLAS21lqe | AT2021iuk | 12:25:58.462 | +06:44:27.03 | 0.08 | Ia | -2 | (4)
Notes:
When the redshift is given to 2 decimal places, it is derived from the SN spectrum.
Otherwise, the redshift is determined from the host galaxy.
(1) We find good template fits with SNe Ib at z~0.02. The SN redshift is consistent with NGC 4923 (at z = 0.018), suggesting that the SN is associated with this galaxy or the Coma cluster, in which NGC 4923 resides. The SN is offset from NGC 4923 by 59", corresponding to 23.7 kpc (using H0 = 73 km/s/Mpc and Virgo+GA infall model) if at the distance of NGC 4923. An SDSS spectrum of NGC 4923, which has an S0 classification, has no indication of star formation. The remote location of this transient and its low-luminosity (M_r ~ -15.5 mag) is consistent with the ''Ca-rich'' class (Filippenko et al., 2003, IAUC 8159 ; Perets et al., 2010, Nature, 465, 322). We also note that photometry from the Young Supernova Experiment (Jones et al., 2021, ApJ, 908, 143) show a fast rise of <2 days, followed by a decline, and now with a second rise in red bands, consistent with the early behaviour of SN 2019ehk (Jacobson-Galan et al., 2020, ApJ, 898, 166).
(2) Redshift derived from the Na I D doublet. We measure an Si II 6355 velocity of -11,300 km/s.
(3) We measure an Si II 6355 velocity of -11,500 km/s.
(4) We measure an Si II 6355 velocity of -13,000 km/s.
