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: ATLAS (ATLAS17deh)
The Asiago Transient Classification Program (Tomasella et al. 2014, AN, 335, 841) reports the spectroscopic observation of ATLAS17dek (aka AT2017cki, candidate SN close to the galaxy SDSSJ105613.78+560813.2) and ATLAS17deh (aka AT2017ckj) in SDSS J160943.67+480209.4 at z=0.037.
The observations were performed with the Asiago 1.82 m Copernico Telescope equipped with AFOSC (range 340-820 nm; resolution 1.4 nm).
Survey Name | IAU Name | Discovery date (UT) | Discovery mag | Observation (UT) | Type | z | phase | Notes| ATLAS17dek | SN 2017cki |2017-03-22 09:51:50 | 18.34 |2017-03-27 21:58 | SN Ia | 0.04 | max | (1) | ATLAS17deh | SN 2017ckj |2017-03-26 13:17:45 | 17.81 |2017-03-28 02:29 | core-collapse | 0.037| pre-max | (2) |
(1) A good match is obtained with several Type Ia SNe around B-band maximum light. From the position of the minimum of the Si II 635.5nm feature, we infer an expansion velocity of about 11200 km/s for the ejected material, assuming a redshift derived from the match with libraries of SNe Ia spectra (zmed=0.0414 +/- 0.006).
(2) The AFOSC spectrum shows a blue (T about 21500 K) almost featureless continuum, typically seen in young core collapse SNe a few days after explosion. An un-resolved emission identified with He II 468.6 nm is clearly seen. At the given redshift (derived from the narrow He II emission and from the SDSS galaxy spectrum), very faint unresolved emission of Halpha and HeI 587.6 nm are also discernible. Further observations are ongoing.