Spectroscopic classification of Gaia18ddp: Type Ia Supernova in the extended halo of the brightest cluster galaxy
ATel #12233; Min-Su Shin (Korea Astronomy and Space Science Institute), Jae-Woo Kim (KASI), Myungshin Im (Seoul National University), Joonho Kim (SNU), Chung-Uk Lee (KASI), Seung-Lee Kim (KASI)
on 20 Nov 2018; 23:36 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: Min-Su Shin (msshin@kasi.re.kr)
Subjects: Optical, Supernovae
The transient Gaia18ddp (also known as AT 2018hnq) was reported on Oct. 24, 2018 (UT) as a potential candidate of supernovae. We also identified the candidate from the follow-up observation with the Lee Sang Gak Telescope on Oct. 26, 2018 (UT). Our examination of the Hubble Legacy Archive data shows that the transient might be a supernova explosion in the extended stellar halo of the brightest cluster galaxy of the cluster Abell 3395.
We acquired spectra of the transient Gaia18ddp by using Gemini GMOS-S in a longslit mode. The spectra acquired on Nov. 11, 2018 (UT) evidently show the spectral features of Type Ia supernovae at the cluster redshift z=0.05.
Our most recent photometric observations made on Nov. 14, 2018 (UT) reveal that the SN is still bright at V ~ 20.3, R ~ 19.9, and I ~ 19.4 Vega mag in images taken by the Korea Microlensing Telescope Network.
We thank the Gemini Observatory and its staff for conducting the observation as a Director's Discretionary Time program.