FLOYDS Classification of KAIT-17A/AT 2017be as an LBV Outburst
ATel #9954; G. Hosseinzadeh, C. McCully, I. Arcavi, D. A. Howell (Las Cumbres Obs./UCSB), S. Valenti (UC Davis)
on 10 Jan 2017; 21:42 UT
Credential Certification: Iair Arcavi (firstname.lastname@example.org)
Subjects: Optical, Supernovae, Transient
We obtained a spectrum of KAIT-17A/AT 2017be, discovered by the Lick Observatory Supernova Search, on 2017 January 10.4 UT with the robotic FLOYDS instrument mounted on the Las Cumbres Observatory 2-meter telescope on Haleakala, Hawai'i. The spectrum shows a H-alpha emission at the redshift of the proposed host galaxy (z=0.001; Garrido, Marcelin, & Amram 2004, MNRAS, 349, 225; via NED) with a width corresponding to ~950 km/s (marginally resolved by the spectrograph) on top of the somewhat blue continuum of the host (SDSS DR13). Given that the discovery magnitude was 18.5 mag, corresponding to an absolute magnitude of ~-11 mag (Tully 1988, Nearby Galaxy Catalog; Sharina, Karachentsev, & Tikhonov 1999, AstL, 25, 322; via NED), we conclude that the transient is likely an LBV outburst (a.k.a. a supernova "impostor"). The spectrum is available on the Transient Name Server.
In addition, one epoch of pre-explosion infrared images is available from HST NICMOS, in which several sources (F160W ~ 19-21 mag) are coincident with the transient's rough position.