Asiago spectroscopic observation of ASASSN-19ku and SN 2019ehk

ATel #12714; L. Tomasella, S. Benetti, E. Cappellaro, M. Turatto (INAF - Osservatorio Astronomico di Padova)
on 2 May 2019; 09:16 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Lina Tomasella (lina.tomasella@oapd.inaf.it)

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The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of ASASSN-19ku (SN2019dwy) and SN 2019ehk. The first target was supplied by the All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014) in Atel#12713, while SN 2019ehk was reported in the Transient Name Server (https://wis-tns.weizmann.ac.il/object/2019ehk) and already classified in Atel #12707 by Dimitriadis et al.

The observation was performed with the Asiago 1.82m Copernico Telescope (+AFOSC; range 340-820 nm; resolution 1.4 nm).

 
Survey name | IAU name | Host galaxy            | Disc. Date (UT)     | Obs. Date (UT)     | redshift.  | type |  phase    | notes  
ASASSN-19ku | 2019dwy  | 2MASX J11141082+7046053|  2019-04-24 17:32:36| 2019-05-01 22:43:34| 0.045      |  Ic  | around max|   1   
SN 2019ehk  | 2019ehk  | NGC 4321               |  2019-04-29 22:27:50| 2019-05-01 20:02:36| 0.005      |  CC  | early     |   2   

(1) The spectrum of this nuclear transient is similar to those of Type Ic supernovae soon after maximum. The redshift has been deduced with SNID/GELATO SN template fitting.

(2) The spectrum still show a red, mostly featureless continuum as described in Atel#12707. The NaID doublet is yet very strong (we measure an EW~0.48 nm) indicating significant dust absorption. A shallow, broad emission line is now clearly visible centred at about 587.6 nm, rest frame, which we identify as He I. Its FWHM implies an expansion velocity of about 15000 km/s. Red-wards of this feature an even shallower, very broad emission is detected, which we interpret as a blend of H-alpha, He I 667.8nm and He I 706.5 nm broad emissions. He I 492.2 nm is possibly also visible in the blue part of the spectrum. We confirm this event as a young core collapse SN in agreement with Atel #12707.

The classification was performed using the GELATO (Harutyunyan et al. 2008, A&A, 488, 383)
and SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tools.

The Asiago classification spectra are posted at the website http://sngroup.oapd.inaf.it.

Padova-Asiago SN Group