Spectroscopic Classification of Six Supernovae
ATel #11860; P. Blanchard, S. Gomez, M. Nicholl, E. Berger (Harvard/CfA)
on 16 Jul 2018; 15:20 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Peter Blanchard (pblanchard@cfa.harvard.edu)
Subjects: Optical, Supernovae
We obtained optical spectroscopic observations of 6 transients reported to the Transient Name Server by the Pan-STARRS Survey for Transients (PSST; Huber et al., ATel #7153; http://star.pst.qub.ac.uk/ps1threepi/ ), the Asteroid Terrestrial-impact Last Alert System (ATLAS; Tonry et al. 2011; ATel #8680), and the Zwicky Transient Facility (ZTF; Bellm & Kulkarni 2017; ATel #11266). We used the LDSS3c Spectrograph with the VPH-All grism mounted on the 6.5m Magellan/Clay Telescope (3700-10000 angstroms). The classifications, shown below, were performed using SNID (Blondin & Tonry, 2007, ApJ, 666, 1024). The redshifts listed below are inferred from the best fitting SNID templates, unless otherwise noted.
Name | RA (J2000) | DEC (J2000) | Obs. Date | Disc. Date | Disc. Source | Disc. Mag | z | Type | Sp. Phase | Notes
AT2018cry | 17:03:28.75 | +00:52:30.2 | 20180708 | 20180617 | ATLAS | 19.6 | 0.08 | Ia | ~20-25 d |
AT2018cou | 14:15:23.73 | -20:00:54.2 | 20180709 | 20180612 | ATLAS | 18.8 | 0.03 | II | ~15-40 d | (1)
AT2018csm | 15:17:08.02 | +01:05:58.9 | 20180709 | 20180619 | ATLAS | 18.8 | 0.04 | Ia-91bg | ~10-20 d | (2)
AT2018dae | 20:37:08.88 | -04:45:18.4 | 20180709 | 20180616 | PSST | 20.1 | 0.05 | II | >100 d |
AT2018cyo | 22:11:56.27 | -04:41:40.4 | 20180709 | 20180621 | PSST | 19.5 | 0.04 | IIn | >100 d |
AT2018cvl | 22:02:55.33 | -07:55:10.7 | 20180709 | 20180625 | ATLAS | 18.4 | 0.0586| Ib/IIb | ~10-30 d | (3)
(1) First observed by PSST on 20180610.
(2) First observed by ZTF on the same night as ATLAS.
(3) SNID returns both Type Ib and IIb matches. Redshift from host galaxy emission lines.
We thank Yuri Beletsky for carrying out the observations.