Liverpool Telescope observations of AT 2018fsy
ATel #12017; M. J. Darnley (LJMU), M. W. Healy (LJMU), S. C. Williams (Lancaster)
on 7 Sep 2018; 19:03 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
Subjects: Optical, Nova, Transient
We conducted spectroscopic observations of AT 2018fsy (see TNS, a nova candidate in M31, using the SPRAT instrument (Piascik et al. 2014) on the 2m-robotic Liverpool Telescope (LT; Steele et al. 2004). Each spectral observation is preceded by a series of (typically at least 3) 10s acquisition images taken either by SPRAT (unfiltered) or IO:O through a Sloan-r' filter. This spectrum consisted of 3×600s of exposure time using the blue-optimised mode of SPRAT.
The spectrum of AT 2018fsy shows a blue continuum punctuated with Balmer lines (Hα-Hδ), Na I-D, and possibly Fe II (42) and O I (7773Å), all of which show evidence of P Cygni profiles. The FWHM of the emission portion of the Hα line is 900±200 km/s. The terminal velocity of the absorption portion of the Hα line may be as high as 2000 km/s.
The spectrum of AT 2018fsy is consistent with the early, post-fireball, stage of a classical nova eruption within M31. Given the line widths and the possible presence of Fe II lines, this is more likely an Fe II nova.
LT follow-up photometry of AT 2018fsy will commence. We will also attempt to obtain a later time spectrum.
