Asiago spectroscopic classification of two transients
ATel #14030; L. Tomasella, S. Benetti, E. Cappellaro, N. Elias-Rosa, A. Pastorello (INAF-OAPd)
on 18 Sep 2020; 13:48 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Stefano Benetti (stefano.benetti@inaf.it)
Subjects: Optical, Cataclysmic Variable, Supernovae
The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of ZTF20abzgddp (AT 2020tjb) and ASASSN-20ko (SN 2020rvf).
The targets were supplied by the Zwicky Transient Facility (https://www.ztf.caltech.edu/; Kulkarni et al. 2018, ATel #11266), and by the All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al.
2014) and reported in the Transient Name Server (TNS).
The observations were obtained with the Asiago 1.82m Copernico Telescope (+ AFOSC grism#4; range 340-820 nm; resolution 1.4 nm).
Survey name | IAU name | Host galaxy | Disc. Date (UT) | Obs. Date (UT) | redshift | type | phase | notes
ZTF20abzgddp| SN 2020tjb | hostless | 2020-09-15 04:00:28.80 | 2020-09-17 23:19:53.8 | 0 | CV | - | 1
ASASSN-20ko | SN 2020rvf | CGCG 465-012 | 2020-08-22 02:52:48.00 | 2020-09-18 00:17:24.3 | 0.022222 | Ic | 20-30d | 2
(1)
The spectrum shows a blue continuum with higher Balmer lines in pure absorption, while Halpha is filled by its emission component and Hbeta shows a weak emission core surrounding broad absorption troughs. These features are typically seen in CVs soon after the outburst.
(2)
The spectrum shows a red continuum and a very intense interstellar NaID (EW~0.72 nm) suggesting a high reddening (E(B-V)~1.2 mag, following Turatto, et al. 2003, fthp.conf, 200). The spectrum is contaminated by the host galaxy nuclear emission making it difficult to decide whether the narrow Halpha is indeed intrinsic to the SN. Assuming the high reddening, GELATO returns a good fit with the type Ic SN 1990aa spectrum 2-3 weeks after maximum but also with the peculiar SN 2002ic. The redshift is from RC3, via NED.
