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Spectroscopic classification of ASASSN-17fy, ASASSN-17gd, and ASASSN-17ge by NUTS (NOT Un-biased Transient Survey)

ATel #10391; E. Kankare (QUB), A. Pastorello (Padova), M. Fraser (UCD), A. Hamanowicz (Warsaw), T. Wevers (Nijmegen RU), Z. Kostrzewa-Rutkowska (SRON), F. Onori (SRON), G. Cannizzaro (SRON), L. Wyrzykowski (Warsaw), P. Jonker (SRON), S. Dong (KIAA-PKU), I. Rivero Losada (NOT) on behalf of the NUTS collaboration.
on 18 May 2017; 14:44 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Erkki Kankare (e.kankare@qub.ac.uk)

Subjects: Optical, Supernovae, Transient

Referred to by ATel #: 10424, 10500

The Nordic Optical Telescope (NOT) Un-biased Transient Survey (NUTS; ATel #8992) reports the spectroscopic classifications of ASASSN-17fy, ASASSN-17gd, and ASASSN-17ge in host galaxies 2MASX J09033237-2120017, UGC 09616 and IC 0939, respectively. The candidates were discovered by the All-Sky Automated Survey for Supernovae (ATEL #8944, #8979).

The observations were performed with the 2.56 m Nordic Optical Telescope equipped with ALFOSC (range 350-950 nm; resolution 1.6 nm FWHM).

 
Survey Name    | IAU Name   | Discovery (UT)  | Discovery mag | Observation (UT) | Redshift | Type | Phase       | Notes  
ASASSN-17fy    | SN2017dwq  | 2017-05-04.04   | 16.9          | 2017-05-17.88    | 0.018    | IIn  | young       | (1)  
ASASSN-17gd    | SN2017eax  | 2017-05-14.38   | 16.6          | 2017-05-17.92    | 0.028    | Ia   | -3 to 0 d   | (2) 
ASASSN-17ge    | SN2017eaz  | 2017-05-14.30   | 17.0          | 2017-05-17.90    | 0.024    | Ia   | +6 to +8 d  | (2) 

(1) Narrow H emission lines, broad P Cygni features of Hbeta and HeI/NaID, and narrow Na ID absorption are detected. The spectrum resembles that of SN 2009ip (Pastorello et al 2013, ApJ, 767, 1; Fraser et al. 2013, MNRAS, 433, 1312), although we cannot rule out some contamination from the host galaxy background. The EW of the Galactic Na ID component is 1.06, and that of the host 2.23. Scaling from the Galactic extinction (Schlafly & Finkbeiner 2011, ApJ, 737, 103) of A_R = 0.34 mag, suggests a total line-of-sight extinction of A_R ~ 1 mag. This yields an absolute magnitude of M ~ -18.5 mag for ASASSN-17fy. (2) Normal Type Ia.

Classifications were performed using the SNID (Blondin and Tonry 2007, ApJ, 666, 1024) tool. Calibrated spectra and additional information can be retrieved in the IAU Transient Name Server.