AstroNote 2020-237

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2020-11-25 19:22:21
Type: Object/s-Discovery/Classification
Las Campanas spectroscopic classification of young optical transients
Authors: Carlos Contreras (LCO), Emilio D. Hueichapan (U. de Chile), Regis Cartier (CTIO/NOIRLab), Hugo Rivera (LCO), Carla Fuentes (LCO) and Alberto Pasten (LCO)
We report the spectroscopic classification of SN 2020aary, SN 2020aatc, SN 2020aaul and SN 2020aauk as young SNe Ia and of SN 2020aatb as a young SN II.

We report the spectroscopic classification of the following transients discovered by Zwicky Transient Facility (; Kulkarni et al. 2018, ATel #11266) and by the All Sky Automated Survey for SuperNovae ASAS-SN (see Shappee et al. 2014, ApJ, 788, 48 and The observations were performed with the IMACS spectrograph mounted on Walter Baade 6.5-m Magellan telescope on Las Campanas Observatory.

We used SNID (Blondin and Tonry, 2007, ApJ, 666, 1024) cross-correlation software to classify the SN candidates spectra. We found three of them to match typical type Ia SNe spectra, while the other two are very young SNe of type Ia and II. For the latter two SNe SNID was not able to provide a good match to the spectra and phase due to their young peculiar spectra.

Show current TNS values
CatalogNameReported RAReported DECReported Obj-TypeReported RedshiftHost NameHost RedshiftNotesRemarksTNS RATNS DECTNS Obj-TypeTNS Redshift
TNS2020aary [ASASSN-20op]03:21:29.882-61:46:11.89SN Ia0.026WISEA J032130.17-614613.0(1,5)03:21:29.860-61:46:11.96
TNS2020aatc [ZTF20actddoh]02:48:16.421-10:15:07.41SN Ia0.01525MCG -02-08-0070.015254(2,4,6)02:48:16.430-10:15:07.52SN Ia0.01525
TNS2020aatb [ZTF20acrzwvx]05:24:46.411-15:56:31.43SN II0.00995NGC 19060.009954(2,4)05:24:46.412-15:56:31.43SN II0.009954
TNS2020aaul [ZTF20actjbaf]08:01:41.410-10:24:21.02SN Ia0.08WISEA J080141.37-102421.9(3,5)08:01:41.403-10:24:21.15SN Ia0.08
TNS2020aauk [ZTF20actiymd]08:17:50.951-05:43:09.67SN Ia0.03943WISEA J081750.69-054305.60.039434(2,5)08:17:50.950-05:43:09.70SN Ia0.03943



  1. Redshift measured from host galaxy narrow emission lines.
  2. Host galaxy redshift from NED.
  3. Redshift obtained from SNID.
  4. The phase is measured the rest-frame time relative to the estimated epoch of the explosion. We estimate the epoch of the explosion as the mid-point between the last non-detection and the first detection.
  5. Phase relative to maximum light estimated using SNID.
  6. The spectrum shows a very broad feature from 675.0 to 835.0 nm, possibly due to C II, O I and Ca II blended spectral features. We measure a velocity for the Si II 6355 feature of 22,200 km/s. Follow-up observations are encouraged.