Spectroscopy and photometry of MASTER OT J004126.22+414350.0 in the Andromeda direction

ATel #9554; S. C. Williams (Lancaster), K. Hornoch (Ondrejov), M. Henze (CSIC-IEEC), M. J. Darnley (LJMU)
on 27 Sep 2016; 08:41 UT
Credential Certification: Steven Williams (scw@astro.ljmu.ac.uk)

Tweet

MASTER OT J004126.22+414350.0 was discovered on 2016 Sep 02.12339 UT (ATel #9470). The transient is coincident with M31N 2013-11b (ATel #9470), which was originally identified as an M31 nova candidate (ATel #5569), but later found to be more likely a red LPV (ATel #5640, #5744).

We obtained spectroscopy of the new transient with the SPRAT spectrograph (Piascik et al. 2014) on the 2m Liverpool Telescope (LT; Steele et al. 2004) on 2016 Sep 09.08 UT. The spectrum has low S/N and revealed no obvious emission or absorption lines, but the continuum is clearly detected.

We also obtained photometry using the IO:O optical imager on the LT on 2016 Sep 09.09 UT. The results of this photometry are:

  
B = 21.53 ± 0.06 
V = 20.02 ± 0.02 
r' = 19.44 ± 0.01 
i' = 18.92 ± 0.03 

We compared the i'-band LT image of the 2016 transient MASTER OT J004126.22+414350.0 with an I-band image of M31N 2013-11b taken with the Danish 1.54m telescope at La Silla on 2013 Dec 1.025 (see ATel #5640). This shows that the position of MASTER OT J004126.22+414350.0 is indeed consistent with it being the same object as M31N 2013-11b (the two images can be seen in the link provided below). The spectroscopic and photometric observations of the transient imply this is unlikely to be a recurrent nova eruption in M31. The colour of the transient also suggests it is unlikely to be a Galactic dwarf nova outburst, but some other variable.

Comparison between 2013 and 2016 transients