Spectroscopic classification of AT2020hat in NGC 5068 by NUTS2 (NOT Un-biased Transient Survey-2)
ATel #13644; A. Reguitti, A. Pastorello, N. Elias-Rosa, I. Salmaso, G. Valerin (INAF-OAPd), R. Kotak (Turku University), M. Fraser (UCD)
on 17 Apr 2020; 16:37 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Andrea Pastorello (andrea.pastorello@oapd.inaf.it)
Subjects: Optical, Transient
The NUTS2 collaboration (Holmbo et al. 2019, ATel #12661) collaboration reports the spectroscopic classification of AT2020hat
(ATLAS20jxk; Chen et al. 2020, TNSAN, 81, 1) in the spiral galaxy NGC 5068. The candidate was discovered by the ATLAS survey (Tonry et al. 2018, PASP, 13, 064505;
Smith et al. 2020, arXiv:2003.09052).
The observation was performed with the 2.56 m Nordic Optical Telescope equipped with ALFOSC on 2020-04-17.02 UT (range 340-980 nm; resolution 1.4 nm).
IAU Name | Survey name | Redshift | Discovery (UT) | Discovery mag | Type | Phase | Notes
AT 2020hat | ATLAS20jxk | 0.002248 | 2020-04-12.475 | 17.83 (ATLAS-o) | LRN | late | (1)
(1) A good match is obtained with spectra of M31-LRN2015 (e.g. Williams et al. 2015, ApJ, 805, L18; Blagorodnova et al. 2020, arXiv:2004.04757) or other luminous red novae after the initial blue light curve maximum (Pastorello et al. 2019, A&A, 630, 75). The spectrum shows a relatively red continuum (T~4800 K) and a very weak unresolved Halpha, with narrow P-Cygni profile. The H&K doublet and the near-infrared triplet of Ca II are prominent in absorption. [Ca II] lines are not clearly detected, ruling out a classification as an Intermediate-Luminosity Red Transients (Pastorello & Fraser 2019, Nature Astron. 3, 676).
The redshift is determined from the position of the minimum of the H&K Ca II lines, which is consistent with that of NGC 5068 (z = 0.002235) reported by Pisano et al. 2011, ApJS, 197, 28.