ePESSTO spectroscopic classification of optical transients
ATel #11967; E. Callis (UCD), Z. Kostrzewa-Rutkowska (SRON/RU), M. Fraser (UCD), J. Anderson (ESO), L. Galbany (U. Pitt), C. Inserra (Southampton), E. Kankare (QUB), 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, O. McBrien (QUB), D. E. Wright (Univ. of Minnesota)
on 18 Aug 2018; 17:07 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Morgan Fraser (morgan.fraser@ucd.ie)
Subjects: Optical, AGN, Supernovae, Transient
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 ATLAS survey, see Tonry et al. (2011, PASP, 123, 58) and Tonry et al. (ATel #8680); 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 ); and the ESA Gaia Photometric Science Alerts Team and DPAC (http://gsaweb.ast.cam.ac.uk/alerts). All observations were performed on the ESO New Technology Telescope at La Silla on 2018 August 17, 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
ATLAS18twk | AT2018fes | 22:56:54.4 | -37:20:48.5 | 20180817 | ATLAS | 17.5 | 0.006 | ? | ? | (1)
ATLAS18sih | AT2018fbl | 22:34:25.4 | -06:57:57.9 | 20180814 | ATLAS | 18.6 | 0.106 | AGN | - |
ASASSN-18sk | AT2018fdx | 23:17:30.0 | -49:48:00.9 | 20180814 | ASASSN | 17.9 | - | CV | - | (2)
ASASSN-18sl | SN2018feq | 01:15:18.5 | -44:55:09.9 | 20180817 | ASASSN | 17.8 | 0.032 | Ia | -8d | (3)
ATLAS18tnc | SN2018exa | 23:48:58.1 | -36:53:13.9 | 20180811 | ATLAS | 18.6 | 0.03 | II | +7d | (4)
ATLAS18tuw | AT2018fds | 03:01:18.7 | -37:04:12.7 | 20180813 | ATLAS | 18.6 | 0.05? | SN? | - | (5)
ASASSN-18sd | SN2018fcu | 04:17:54.7 | -49:54:28.4 | 20180813 | ASASSN | 17.7 | 0.05 | Ia | ~0d |
ATLAS18tec | | 02:30:59.8 | -17:20:26.9 | 20180807 | ATLAS | 18.0 | ? | ? | ? | (6)
Gaia18cdh | SN2018faz | 04:28:47.4 | 06:28:11.5 | 20180812 | Gaia | 18.7 | 0.04 | II | +7d |
Gaia18cet | SN2018fcx | 04:05:56.7 | -15:08:43.6 | 20180813 | Gaia | 18.5 | 0.025 | IIb | +3w |
(1) AT2018fes appeared to be located 2" from the centre of NGC 7421 in ATLAS difference images. No source was visible on an EFOSC2 acquisition image, and a spectrum centered on the host nucleus appears to contain only galaxy light.
(2) Weak, narrow Halpha emission on a blue continuum.
(3) Best matches are to SN 1991T.
(4) Spectrum is very blue, but with weak broad Balmer lines consistent with a young Type II SN.
(5) Previously classified in ATel #11965. The spectrum taken on Aug 17 is less blue than the spectrum taken on the preceding night, as expected for a very young SN. In ATel #11965 the wavelengths of the weak emission features seen in the Aug 16 spectrum were incorrectly reported. The first weak feature is actually at ~4945 Ang, possibly on top of a broader (~100 Ang) bump. A second weak feature is at ~4390 Ang. The first weak feature may be associated with a blend of He and high-ionization C/N lines often seen in very young SNe, implying a redshift of z=0.05.
(6) Blue, with some possible very weak broad features between 5000 and 6500 Ang.
