Spectroscopic observations of SN2016hkn and ASASSN-16mx by NUTS (NOT Un-biased Transient Survey)
ATel #9728; G. Cannizzaro (SRON), M. Fraser (University College Dublin), N. Elias-Rosa (Padova), S. Dong (KIAA-PKU), R. Tronsgaard, G. Fedorets, T. Pursimo (NOT) on behalf of the NUTS collaboration
on 7 Nov 2016; 20:21 UT
Credential Certification: Morgan Fraser (mf@ast.cam.ac.uk)
Subjects: Optical, Cataclysmic Variable, Supernovae, Transient
The Nordic Optical Telescope (NOT) Unbiased Transient Survey (NUTS; ATel #8992) reports the spectroscopic classification of the transient SN2016hkn in the host galaxy NGC 819, and the hostless transient ASASSN-16mx. The candidates were discovered by the Italian Supernovae Search Project and the ASAS-SN surveys (http://www.astronomy.ohio-state.edu/~assassin/index.shtml) respectively.
The observations were performed with the 2.56 m Nordic Optical Telescope equipped with ALFOSC (range 350-950 nm; resolution 1.6 nm).
Survey Name | IAU Name | Discovery (UT) | Discovery mag | Observation (UT) | Redshift | Type | Phase | Notes
SN2016hkn | SN2016hkn | 2016-10-22.16 | 17.2 | 2016-11-01.11 | 0.022 | SN II | >+2 weeks | (1)
ASASSN-16mx | AT2016hvq | 2016-11-02.15 | 16.8 | 2016-11-06.81 | - | Stellar | - | (2)
(1) Previously classified by Pan et al. as a Type IIb SN (ATel #9696). The spectrum is relatively flat in the continuum, and shows broad, P-Cygni profiles in Halpha, and Ca lines. The minimum of the absorption in Halpha is at a velocity of ~14,000 km/s, and the spectrum is consistent with a Type II SN a few weeks after explosion. The absolute magnitude (-17.5) is relatively bright for a Type IIP SN, but is consistent with other IIb SNe.
(2) The spectrum is blue, and featureless with the exception of Hbeta and higher absorption lines at their rest wavelength. The temperature of ASASSN-16mx is between 35,000 and 45,000 as measured from a blackbody fit, consistent with a CV in outburst. We note that the transient is at relatively high galactic latitude (-49 deg).
Classifications were performed using the GELATO (Harutyunyan et al. 2008, A&A, 488, 383) and SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tools. Calibrated spectra and additional information can be retrieved in the IAU Transient Name Server.
