AstroNote 2021-12

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2021-01-09 20:56:11
Type: Object/s-Discovery/Classification
ePESSTO+ spectroscopic classification of optical transients
Authors: J. Gillanders, S. Srivastav, M. Fulton, K. W. Smith, S. J. Smartt, L. J. Shingles (QUB), S. Prentice (TCD), C. Gutierrez (Turku), J. Anderson (ESO), T. Muller Bravo (Southampton), T.-W. Chen (Stockholm), M. Gromadzki (Warsaw), C. Inserra (Cardiff), E. Kankare (Turku), M. Nicholl (Birmingham), E. Zimmerman, O. Yaron (Weizmann), D. Young (QUB), I. Manulis (Weizmann), J. Tonry,  L. Denneau, A. Heinze, H. Weiland (IfA, Univ. of Hawaii),  B. Stalder (LSST), A. Rest (STScI), O. McBrien (QUB)
Source Group: ePESSTO+
This report includes classifications of 5 Type Ia's, 1 Type Ibc, 3 Type II's and 1 uncertain transient. 2021ok is an orphan transient whose spectrum resembles a blue continuum with possible shallow features. We also obtained a spectrum of the lensed transient 2021ia, however, the spectrum was dominated by quasar light and therefore could not distinguish a classification. We encourage follow-up observations.

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 ATLAS survey (Smith et al. 2020 2020arXiv200309052S) and 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), and by the ALeRCE broker (Forster et al. 2020 

Observations were performed on the ESO New Technology Telescope (NTT) at La Silla on the night of 2021 January 08, 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 (via WISeREP) and the IAU Transient Name Server.

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

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftSourcePhase (days)RemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2020aeth [ZTF20acyyavb]11:41:28.413-02:15:03.19SN Ia0.048SDSS J114128.12-021502.70.0480665ZTF+4 to +7Consistent with the classification reported in the TNS Classification Report No. 8512. Redshift reported from host.11:41:28.410-02:15:03.28SN Ia0.048
TNS2021hq [ZTF21aaafzwx]07:31:26.045+05:32:56.08SN Ia0.08WISEA J073126.04+053256.1ZTF-7 to -4Redshift acquired from SNID template match as there is no known host redshift.07:31:26.045+05:32:56.08SN Ia0.08
TNS2021ia [ZTF21aabgpub]11:34:40.607-21:03:22.68Other2M 1134-2103ZTFTransient was difficult to distinguish from quasar Image-A during observations. Spectrum is dominated by light from Quasar. Unable to deduce a classification.11:34:40.607-21:03:22.68Other
TNS2021jj [ATLAS21abw]13:17:24.348-16:27:35.01SN Ia0.022MASX J13172425-1627312ATLAS-7 to -4Redshift acquired from SNID template match as there is no known redshift.13:17:24.348-16:27:35.01SN Ia0.02
TNS2021nm [ATLAS21anq]12:46:39.357-37:56:46.32SN Ia0.054WISEA J124639.35-375647.0ATLAS-3 to +3Narrow H-alpha from host implies a redshift of z = 0.054.12:46:39.357-37:56:46.32SN Ia0.054
TNS2021nx [ATLAS21arg]02:37:13.231-27:30:57.47SN II0.0582MASX J02371337-2730570ATLAS-7 to -4Spectrum shows narrow Balmer emission features and a reasonable match to SN2006bc. H-alpha emission implies a redshift of z = 0.058.02:37:13.231-27:30:57.47SN II0.058
TNS2021ok [ATLAS21asi]05:31:31.528-20:31:14.65SN IIATLASSpectrum resembles a featureless blue continuum with a bump at ~5100A. Redshift is unclear.05:31:31.522-20:31:14.51SN II
TNS2021os [ZTF21aabygea]12:02:54.082+05:36:53.15SN II0.019CGCG 041-0270.019323ZTF-7 to -4Redshift reported from host.12:02:54.070+05:36:53.17SN II0.019
TNS2021pp [ZTF21aaahzpr]11:49:11.607-02:17:11.20SN Ia0.09SDSS J114911.57-021711.6ZTF-3 to +3Spectrum matches well with super-chandra sn06gz around peak, but is not as bright: M_g = -19.2 from ZTF lightcurve. Also possible to obtain reasonable matches with Type Ia-91T and normal Type Ia. Redshift acquired from SNID template match as there is no known host redshift.11:49:11.600-02:17:11.36SN Ia0.09
TNS2021qv [ZTF21aabyifm]12:29:38.942+09:29:50.53SN Ib/c0.024VCC 12060.024514ZTF-7 to -4Redshift reported from host.12:29:38.942+09:29:50.36SN Ib/c0.024