Spectroscopic Classifications of Optical Transients with SOAR
ATel #10225; Y.-C. Pan, T. Takaro, R. Chowdhury, R. J. Foley (UCSC), S. W. Jha (Rutgers), A. Rest (STScI), D. Scolnic (Chicago/KICP)
on 29 Mar 2017; 21:03 UT
Credential Certification: Yen-Chen Pan (firstname.lastname@example.org)
Subjects: Optical, Supernovae
We report the following classifications of optical transients from spectroscopic observations with the Goodman spectrograph on the Southern Astrophysical Research (SOAR) telescope. Targets were supplied by ASAS-SN, ATLAS, and PTSS. All observations were made on 2017 Mar 29 UT. Classifications were performed with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024).
Name | IAU Name | RA (J2000) | Dec (J2000) | z | Type | Phase | Notes
ATLAS17cpj | AT2017cfo | 10:38:12.91 | +28:07:02.0 | 0.042 | II | | (1)
ATLAS17dcl | AT2017cjt | 03:42:50.76 | -01:52:28.98 | 0.009 | Ia | -8d | (2)
ATLAS17dfo | AT2017ckq | 10:44:25.38 | -32:12:32.80 | 0.010 | Ia | -9d | (3)
ASASSN-17ds | AT2017cfq | 08:03:55.21 | +26:31:12.73 | 0.022 | II | |
PSN J12140783-1549026 | | 12:14:07.83 | -15:49:02.60 | 0.097 | Ia | +25d |
PTSS17-niq | AT2017ckd | 14:20:16.69 | +15:20:29.57 | 0.068 | Ia | -1d | (4)
PTSS17-nht | AT2017ckb | 14:25:43.02 | +11:44:12.20 | 0.05 | Ia | +2d | (5)
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) Fraser et al. (ATEL #10212) classified this as a possible luminous SN II at z = 0.042. We further confirm the redshift using multiple narrow galactic emission lines as well as Hydrogen absorption features. We measure an H-beta velocity of -12,500 km/s, which is higher than most SNe II. Additionally, we see a relatively strong feature consistent with He I 5876 blueshifted by -11,200 km/s. Overall, the spectrum shares some similarity with SNe IIb, especially SN 1993J 17 days before peak, but we find no exceptional matches.
(2) We measure an Si II 6355 velocity of -11,700 km/s.
(3) We measure an Si II 6355 velocity of -10,900 km/s.
(4) We measure an Si II 6355 velocity of -11,400 km/s.
(5) SN 1991bg-like object.