SALT spectroscopic classification of nuclear transient Gaia18abb/AT2018J as SN Ia/Ic
ATel #11128; M. Gromadzki, L. Wyrzykowski (Warsaw Observatory), D. A.H. Buckley (SAAO).
on 5 Jan 2018; 12:21 UT
Credential Certification: Lukasz Wyrzykowski (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
We report on SALT spectroscopy of transient Gaia18abb/AT2018J, discovered by Gaia Science Alerts program on 2018-01-02. The transient was detected in the nucleus of galaxy 2MASX J11005714-2547135. A low resolution (R = 350) SALT/RSS spectra was taken on 2018-01-03, under the SALT Large Programme on transients (2016-2-LSP-001, PI: Buckley). The spectrum is available on Transient Name Server (TNS) entry for 2018J.
The spectroscopic classification with SNID code (Blondin & Tonry 2007, ApJ, 666, 1024) gave an equally poor match to SN type Ia and Ic, probably due to the presence of host galaxy features, primarily narrow Halpha at z=0.076. Visual comparison with spectra of supernovae templates suggests a SN type Ia at about a week past maximum or SN type Ic few days before maximum.
Name | IAU name | RA (J2000) | Dec (J2000) | Disc. Date | Disc. Mag | Obs. Date | z | Host | Type | Notes
Gaia18abb | AT2018J | 11:00:57.11 | -25:47:13.27 | 2018-01-02 | 18.06 | 2018-01-03 | 0.076 | 2MASX J11005714-2547135 | SN Ia/Ic | Ia+1 week or Ic -2 days
We acknowledge ESA Gaia, DPAC and the Photometric Science Alerts Team (http://gsaweb.ast.cam.ac.uk/alerts).