The program started in 2011 with the aim to classify all transients that are accessible from Asiago and are bright enough for our telescope/instrumentation. We use mainly the 1.82m Copernico telescope of Cima Ekar and, if not available, the 1.22m Galileo telescope of the Pennar station. A few cases of transients classified by our group with other facilities (eg. TNG) are included in the database.
Transient classification information and spectra (fits format) are made immediately available at our site. The spectra are semi-automatic reduction with archive calibration data. Please keep this in mind when using them.
For SN classification we compare the output of two automatic SN classification codes: Gelato (Harutyunyan et al. 2008, A&A 488, 383) and SNID (Blondin and Tonry 2007, Ap.J. 666, 1024).
If you use some of the information posted in these pages please make a reference to the paper Tomasella etal. 2014, A.N. 335, 841.
Discovered by: ASAS-SN
The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic classification of ASAS-SN18ck, ASAS-SN18cp, ASAS-SN18cq and ASASSN-18cj, discovered during the ongoing All Sky Automated Survey for SuperNovae (ASAS-SN, Shappee et al. 2014, Atel #11178).
The observations were performed with the Asiago 1.82 m Copernico Telescope equipped with AFOSC (range 340-820 nm; resolution 1.3 nm).
Survey Name | IAI Name | Discovery date (UT) | Discovery mag | Observation (UT) | Type | z | Notes| ASAS-SN18ck | SN2018tr | 2018-02-13.30 | 17.7 |201802-14 20:32:00 | Ia | 0.045 | (1) | ASAS-SN18cp | SN2018tz | 2018-02-13.28 | 17.9 |2018-02-14 21:42:00 | Ia | 0.047 | (2) | ASAS-SN18cq | SN2018ub | 2018-02-13.37 | 18.1 |2018-02-14 23:34:00 | II | 0.023 | (3) | ASAS-SN18cj | SN2018tq | 2018-02-10.28 | 18.0 |2018-02-14 23:54:00 | Ia | 0.028 | (4) |
(1) The spectrum of ASAS-SN18ck is consistent with Type Ia SNe about one week before maximum light. The red continuum of the spectrum can be attributed to line-of-sight reddening (E(B-V) of about 0.7 mag) . The velocity of the ejecta, as measured from SiII 635.5 nm, is around 10300 km/s.
(2) Good matches are found with normal Type Ia SNe / 91T-like about few days before maximum light. From the shallow Si II 635.5 nm absorption an expansion velocity of ~10800 km/s is derived.
(3) The redshift of the host galaxy is reported by Grogin et al. 1998 (ApJS 119, via NED, z=0.023356 +/- 0.000053) and it is confirmed from the measurement of the narrow emission superimposed to the broad Halpha feature. A good match is obtained with the Type II Plateau SN 2007od (Inserra et al. 2010, MNRAS 417, 261) two/three weeks after explosion. Along with the prominent Halpha we identify HeI, Hbeta, Hgamma, Fe II, Sc II, and Ca II H&K lines. From the position of the P-Cygni absorption of the Hbeta line, we infer an expansion velocity of ~8400 km/s for the ejected material.
(4) A good match is found with Type Ia SNe one week before maximum light. The velocity of the ejecta, as measured from SiII 635.5 nm, absorption is ~13200 km/s.