ePESSTO spectroscopic classification of optical transients
ATel #11474; C. Vogl (MPA), S. Taubenberger, A. Floers (ESO), L. Tomasella, A. Pastorello (INAF-Padova Observatory), L. Galbany (Pittsburgh), C. Gall (DARK, KU), J. Lyman (Warwick),C. Inserra (Southampton), E. Kankare (QUB), K. Maguire, S. J. Smartt (QUB), O. Yaron (Weizmann), D. Young (QUB), J. Tonry, L. Denneau, A. Heinze, H. Weiland (IfA, Univ. of Hawaii), B. Stalder (LSST), A. Rest (STScI), K. W. Smith, O. McBrien (QUB)
on 24 Mar 2018; 19:17 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Andrea Pastorello (andrea.pastorello@oapd.inaf.it)
Subjects: Optical, Supernovae
ePESSTO, the extended Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40; http://www.pessto.org ),
reports the following supernova classifications. Targets were supplied by M. Villi and the Catalina Real-time Transient Survey (CRTS; Drake et al. 2009, ApJ, 696, 870; http://crts.caltech.edu/ ), the ATLAS survey, see Tonry et al. (2011, PASP, 123, 58) and Tonry et al. (ATel #8680), and the All Sky Automated Survey for SuperNovae (ASAS-SN; see Shappee et al. 2014, ApJ, 788, 48 and http://www.astronomy.ohio-state.edu/~assassin/index.shtml ).
All observations were performed on the ESO New Technology Telescope at La Silla on 2018 March 24 UT, using EFOSC2 and Grism 13 (3985-9315A, 18A resolution). Classifications were done with SNID (Blondin & Tonry, 2007, ApJ, 666, 1024) and GELATO (Harutyunyan et al., 2008, A&A, 488, 383). Classification spectra and additional details can be obtained
from http://www.pessto.org (via WISeREP) and the IAU Transient Name Server.
Survey Name | IAU Name | RA (J2000) | Dec (J2000) | Disc. Date | Source | Discovery Mag. | z | Type | Phase | Notes
SNhunt360 | SN 2018akj | 12 27 11.33 | -07 41 48.48 | 2018 03 21.32 | M. Villi and CRTS | 18.9 (V-CRTS) | 0.029307 | Ib | around max | (1)
ATLAS18mkz | SN 2017kam | 13 42 43.89 | -24 20 07.12 | 2017 12 24.64 | ATLAS | 19.043 (o-ATLAS) | 0.022496 | II-pec | 3 months | (2)
ASASSN-18dt | SN 2018yh | 14 09 01.38 | -30 33 26.46 | 2018 02 24.25 | ASAS-SN | 16.5 (V-Johnson) | 0.023436 | Ia | 30d after max | (3)
(1) The spectrum of SNhunt360 resembles that of a Type Ib SN at the maximum light, showing the classical features of stripped-envelope SNe
(Fe II, Mg I, O I, Ca II, Na ID) along with clearly detectable He I lines (587.6 blended with Na I; 667.8, 706.5 and 728.1 nm). The expansion velocity of the SN ejecta, as inferred from the position of the minimum of the Si II 635.5 nm line, is about 13100 km/s, while a velocity of about 11200 km/s is obtained for the He I lines. The redshift of the host galaxy MCG -01-32-011 is from The 6dF Galaxy Survey Data Release 3 (Jones et al. 2009).
(2) The spectrum of ATLAS18mks is that of an evolved Type II SN. It shows prominent Balmer lines, and Fe II, Na I and Ca II features with P Cygni profiles. The broad Halpha emission component (FWHM 8000 ~ km/s) dominates over the absorption. An unusual absorption feature is visible
at about 620 nm (rest wavelength), and it can be due to an high-velocity Halpha component or (more likely) Si II 635.5 nm. The object was discovered about three months ago and, later on, experienced a considerable brightening by about 2 magnitudes. The overall light curve evolution resembles that of the peculiar SN 1987A. The redshift of the host galaxy, ESO 509- G 095, is from The 6dF Galaxy Survey Data Release 3 (Jones et al. 2009).
(3) The spectrum of ASASSN-18dt well matches that of the Type Ia SN 2002bo (Benetti et al. 2004, MNRAS, 348, 261) about 1 month after the B-band maximum light. The redshift of the host galaxy, 2MASX J14090127-3033321, is from Huchra et al. 2012, ApJS, 199, 26.
