Spectroscopic Classifications of Optical Transients with Keck I + LRIS
ATel #14094; M. R. Siebert, S. Tinyanont, K. Taggart, G. Dimitriadis, R. J. Foley (UCSC)
on 14 Oct 2020; 22:25 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Georgios Dimitriadis (gdimitri@ucsc.edu)
Subjects: Optical, Supernovae
We report the classification of the optical transients from spectroscopic observations with the LRIS spectrograph on the Keck I telescope, made on 2020 Oct 14 UT. The targets were supplied by ATLAS, YSE, and ZTF as reported by ALeRCE, SGLF, and ZTF itself. The classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).
Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes
PS20hjr | AT2020tfy | 22:31:04.15 | +36:41:08.03 | 0.23 | Ia | +30d |
PS20hlj | SN2020thx | 01:29:08.37 | -14:47:38.32 | 0.084 | II | +30d | (1)
PS20hos | AT2020tqz | 22:12:08.65 | +00:07:24.46 | 0.136 | Ia | +30d |
ZTF20accbsxa | AT2020twp | 22:18:35.42 | +05:20:01.25 | 0.074 | Ic | +15d | (2)
ZTF20acbcfhk | AT2020tzs | 22:15:02.23 | +00:27:54.41 | 0.057 | II | +15d | (3)
ZTF20acflmyv | AT2020ulz | 04:24:51.06 | -10:56:03.43 | 0.103 | Ia | +3d | (4)
PS20hyz | AT2020usm | 23:58:41.19 | +29:00:31.17 | 0.104 | Ia | +8d |
PS20hzt | AT2020utm | 03:15:27.45 | -03:00:38.19 | 0.044 | IIn | +40d | (5)
ZTF20acgmflv | AT2020vbj | 22:18:32.59 | +35:37:59.79 | 0.116 | Ia-91T | -5d | (6)
ZTF20achaxsk | AT2020vdk | 00:54:18.67 | -14:41:23.47 | 0.074 | SN | +3d | (7)
ATLAS20bdfs | AT2020vwu | 05:47:38.18 | -25:30:35.54 | 0.042 | II | +40d | (8)
ZTF20acigusw | AT2020vyv | 22:50:25.38 | +08:50:41.91 | 0.062 | II | | (9)
ZTF20acinaeq | AT2020wfg | 08:25:46.13 | +43:18:14.94 | 0.108 | Ia | -5d | (10)
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) Previously classified as a SN but with no definitive class (Dimitriadis et al., 2020, TNSCR, 2840). We measure an H-alpha velocity of -8,000 km/s. (2) Some possible He absorption, but spectrum is most consistent with those of SNe Ic. (3) We measure an H-alpha velocity of -8,000 km/s. (4) We measure an Si II 6355 velocity of -11,600 km/s. (5) H alpha has a Lorentzian profile with FWHM of 430 km/s and FWZI of ~2000 km/s. The phase is from the estimated explosion epoch of Sep 1, between the first detection and last non-detection. (6) Spectrum is similar to that of SN 1991T. We measure an Si II 6355 velocity of -11,600 km/s. (7) Blue continuum, with narrow H alpha absorption blueshifted by -400 km/s and some weak broad spectral features. (8) We measure an H-alpha velocity of -9,000 km/s. (9) Blue continuum with weak, broad H alpha. Its absolute magnitude in the first ZTF epoch was Mg = -18.2 mag. (10) We measure an Si II velocity of -11,900 km/s.
