ePESSTO spectroscopic classification of optical transients
ATel #11669; P. Clark, O. McBrien, E. Kankare (QUB), J. Anderson (ESO), L. Galbany (U. Pitt), A. Pastorello (INAF-OAPd), L. Izzo (IAA-CSIC), C. Inserra (Southampton), K. Maguire (QUB), S. J. Smartt (QUB), O. Yaron (Weizmann), D. R. Young (QUB), I. Manulis (Weizmann), J. Tonry, L. Denneau, A. Heinze, H. Weiland (IfA, Univ. of Hawaii), B. Stalder (LSST), A. Rest (STScI), K. W. Smith (QUB), D. E. Wright (Univ. of Minnesota), S. Wyatt (Arizona), D. Sand (Arizona), S. Valenti (UC Davis), S. Yang (INAF-OAPd), D. E. Reichart, J. B. Haislip, V. Kouprianov (UNC)
on 23 May 2018; 17:21 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Erkki Kankare (e.kankare@qub.ac.uk)
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 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 ); the ATLAS survey, see Tonry et al. (2011, PASP, 123, 58) and Tonry et al. (ATel #8680); the ESA Gaia Photometric Science Alerts Team and DPAC (http://gsaweb.ast.cam.ac.uk/alerts); and the D<40 Mpc (DLT40) one day cadence SN search (http://dark.physics.ucdavis.edu/dlt40/DLT40). All observations were performed on the ESO New Technology Telescope at La Silla on 2018 May 22, 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 | Disc Mag | z | Type | Phase | Notes
ASASSN-18kr | SN2018bui | 14 20 43.7 | +13 41 44.7 | 20180518 | ASASSN | 17.9 | 0.020 | II | +12 | (1)
ATLAS18pkq | SN2018btp | 14 00 35.8 | -07 44 06.1 | 20180514 | ATLAS | 19.1 | 0.076 | Ia | +4 to +7 | (2)
Gaia18bgu | SN2018bwd | 14 50 50.5 | -77 52 56.2 | 20180520 | Gaia | 17.5 | 0.014 | II | Young | (3)
Gaia18bgw | AT2018bwf | 18 56 13.0 | -38 53 41.4 | 20180519 | Gaia | 18.4 | 0.0 | CV | - | (4)
DLT18x | AT2018bwo | 00 14 01.7 | -23 11 35.2 | 20180522 | DLT40 | 16.4 | 0.002 | Stellar | ? | (5)
(1) Blue continuum with intermediate-width Balmer and He II 4686 emission lines. ATLAS lightcurve shows that it is now +12 days old with a very restrictive explosion epoch (sensitive down to M_o ~ -15 mag).
(2) Normal Type Ia SN.
(3) Young Type II SN, about 1 week after the explosion. He I is very strong, and there is no trace of Fe II lines. Relatively red likely due to some line of sight extinction.
(4) Blue continuum with a Halpha emission feature at z = 0.
(5) Red continuum, with a forest of narrow metal lines in absorption. The spectrum is similar to that of a K-type star, an Fe nova or even a luminous red nova at later stages. Assuming that NGC 45 (d = 6.6 Mpc) is the host galaxy of AT2018bwo, this would provide an absolute magnitude of -12.67 mag for the transient, which makes the luminous red nova classification more plausible.
