Spectral classification of nuclear transient OGLE16cwa as SN Ia-CSM.
ATel #10493; M. Gromadzki, A. Hamanowicz, L. Wyrzykowski (Warsaw University Astronomical Observatory, Poland)
on 14 Jun 2017; 21:28 UT
Credential Certification: Lukasz Wyrzykowski (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
The optical transient OGLE16cwa was discovered on 2016-08-12 (Wyrzykowski et al.; ATel #9543) by the OGLE-IV Transient Detection System (Wyrzykowski et al. 2014, AcA,64,197; Kozlowski et al. 2013; Klencki et al. 2016, AcA, 66,15). Transient was initially classified as SN type II in post-max phase (Prentice et al.; ATel #9516) by PESSTO, the Public ESO Spectroscopic Survey for Transient Objects (see Smartt et al. 2015, A&A, 579, 40 http://www.pessto.org ), based on NTT spectrum obtained on 2016-09-20.
The spectrum of host galaxy was obtained with SALT/RSS on 2017-06-13. It shows narrow emission lines of H_alpha, H_beta, SII, [O III] and [OII] at z=0.09. The spectroscopic classification was done on residual spectrum after host subtraction using SNID code (Blondin & Tonry 2007, ApJ, 666, 1024) and is consistent with SN Type Ia-CSM 44 days after maximum.