DRAFT
2020-11-09 17:55:28
Type: Object/s-Discovery/Classification
ePESSTO+ spectroscopic classification of optical transients
Authors: Nada Ihanec, Mariusz Gromadzki (Warsaw), Seán Brennan, Morgan Fraser, Robert Byrne (UCD), Michel Dennefeld(IAP), Shubham Srivastav (QUB), Giuliano Pignata (UNAB),J. Anderson (ESO), T. Muller Bravo (Southampton), T.-W. Chen (Stockholm), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), M. Nicholl (Birmingham), I. Irani, O. Yaron (Weizmann), D. Young (QUB), I. Manulis (Weizmann)
Source Group: ePESSTO+
Abstract:
This report includes classifications of 4 type Ia's and 2 Type II's. AT2020yyw is consistent with a Type II a few days after explosion. Its host galaxy is not in NED, implying that it is potentially low luminosity. AT2020ykb shows very weak and narrow Halpha and Hbeta emission at z=0.09 . Transient has bright absolute magnitude -18.7, no apparent host, and has not developed clear SN features for two weeks. We encourage followup of this transient.

ePESSTO+, the advanced Public ESO Spectroscopic Survey for Transient Objects (Smartt et al. 2015 2015A&A...579A..40S), reports the following supernova classifications.

Targets were supplied by the Pan-STARRS Survey for Transients (Chambers et al. 2016 2016arXiv161205560C), the ATLAS survey (Smith et al. 2020 2020arXiv200309052S), the Zwicky Transient Facility ZTF (Bellm et al. 2019 2019PASP..131a8002B) - data stream processed through the Lasair broker (Smith, Williams, Young et al. 2019 2019RNAAS...3a..26S), the All Sky Automated Survey for SuperNovae ASAS-SN (see Shappee et al. 2014 2014ApJ...788...48S), and by the ESA Gaia Photometric Science Alerts Team DPAC.

Observations were performed on the ESO New Technology Telescope (NTT) at La Silla on the night of 2020 Novermber 8, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution). Classifications were done using SNID (Blondin & Tonry 2007 2007ApJ...666.1024B) and GELATO (Harutyunyan et al. 2008 2008A&A...488..383H) and Superfit (Howell et al. 2005 2005ApJ...634.1190H).

The classification spectra and additional details can be obtained from http://www.pessto.org (via WISeREP) and the IAU Transient Name Server.

The classified objects are listed in the Related Objects table below.

Show current TNS values
Catalog Name Reported RA Reported DEC Reported Obj-Type Reported Redshift Host Name Host Redshift Source Phase (days) Remarks TNS RA TNS DEC TNS Obj-Type TNS Redshift
TNS 2020yyg [ZTF20acowddo] 01:54:05.891 +07:08:58.72 SN Ia 0.073 SDSS J015405.95+070859.8 0.051 -7 to -4 Redshift measured with SNID 01:54:05.886 +07:08:58.76 SN Ia 0.073
TNS 2020thz [ATLAS20bbem] 02:57:03.406 -34:30:40.29 SN Ia 0.1 >20 Redshift measured with SNID 02:57:03.406 -34:30:40.29 SN Ia 0.1
TNS 2020yyw [Gaia20fcn] 21:15:32.100 -62:42:58.50 SN II 0.03 At max Redshift measured with SNID, Host not in NED, implying low luminosity 21:15:32.100 -62:42:58.50 SN II 0.03
TNS 2020yst [ZTF20acobxlz] 02:34:46.298 -13:27:19.29 SN Ia-91T-like 0.087 LEDA 937757 At max Redshift measured with SNID 02:34:46.300 -13:27:19.14 SN Ia-91T-like 0.09
TNS 2020ykb [ZTF20acocohy] 04:16:09.178 -25:28:27.46 SN II 0.09 Very weak and narrow Halpha and Hbeta emission at z=0.09. Observations 2 weeks from discovery. Transient has bright absolute magnitude of -18.7. No nearby host, possible orphan 04:16:09.178 -25:28:27.46 SN II 0.09
TNS 2020ypw [Gaia20fam] 10:52:39.530 -31:43:11.71 SN Ia 0.06 +11 to +20 Redshift measured using SNID 10:52:39.530 -31:43:11.71 SN Ia 0.06
TNS 2020wtm [ATLAS20bdjv] 21:32:23.341 -44:07:56.92 0.1 Passive Galaxy at z =0.1. Not transient seen in acquisition image 21:32:23.341 -44:07:56.92 Galaxy 0.1
TNS 2020yjx [Gaia20ezw] 05:51:51.810 -75:00:36.58 Featureless continuum. Faint source. Unknown 05:51:51.810 -75:00:36.58

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