Spectroscopic classification of ASASSN-17fe, ASASSN-17fd by NUTS (NOT Un-biased Transient Survey)
ATel #10298; G. Cannizzaro (SRON), Z. Kostrzewa-Rutkowska (SRON), M. Stritzinger (Aarhus University), S. Dong (KIAA-PKU), S. Benetti (INAF-OAPd), M. Fraser (UCD) and R. Tronsgaard Rasmussen (Aarhus University) on behalf of the NUTS collaboration
on 21 Apr 2017; 12:36 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Zuzanna Kostrzewa-Rutkowska (email@example.com)
Subjects: Optical, Supernovae, Transient
Referred to by ATel #: 10306
The Nordic Optical Telescope (NOT) Unbiased Transient Survey (NUTS; ATel #8992) reports the spectroscopic
classification of ASASSN-17fe and ASASSN-17fd (in an anonymous host galaxy and ARK 481 respectively). The candidates were discovered by the All Sky Automated Survey for SuperNovae (ASAS-SN, 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-17fe | 2017dfo | 2017-04-19.11 | 17.03 | 2017-04-20.875 | 0.036 | Ia | -6/-2d | (1)
ASASSN-17fd | 2017dfb | 2017-04-19.5 | 16.5 | 2017-04-21.125 | 0.0256 | Ia-91T | -7/-4d | (2)
(1) ASASSN-17fe is a pre-maximum normal Type Ia supernova. SNID gives good
matches with normal SN Ia between -6 and -2 days. An expansion velocity of about 10600 km/s from the SiII 635.5 nm absorption was measured.
(2) ASASSN-17fd is a pre-maximum 1991T-like Type supernova. GELATO gives good fits with SN 1991T spectra between -7 and -4 days. The redshift has been deduced from a strong NaI-D interstellar absorption. With this z, an expansion velocity of about 10800 km/s from the SiII 635.5 nm was measured.
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.