Recurrent Nova M31N 2008-12a: Liverpool Telescope observation of the waning 2017 eruption
ATel #11149; M. J. Darnley (LJMU), M. W. Healy (LJMU), M. Henze (SDSU), S. C. Williams (Lancaster)
on 9 Jan 2018; 21:28 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
Referred to by ATel #: 11214
The tenth consecutive annual eruption of the recurrent nova M31N 2008-12a was discovered on New Year's Eve 2017 (ATel #11116). A sub-set of the follow-up observations have subsequently been reported in ATels #11117, #11118, #11121, #11124, #11125, #11126, #11130, #11133, #11134, and #11144. Comprehensive multi-wavelength studies of previous eruptions have been published in Darnley et al. 2014, 2015, 2016 and Henze et al. 2014, 2015a, 2015b.
Here we report a set of Liverpool Telescope (Steele et al. 2004) IO:O observations during the 'final decline' phase (t>8 days; see Darnley et al. 2016) of the 2017 eruption. Each of the four reported observations consists of 3×450s exposures taken in dark conditions at airmass ≤1.16 with median seeing of 1''.
Date (UT) Photometry
2018 Jan 09.823±0.008 u'=21.69±0.05
2018 Jan 09.840±0.008 r'=21.81±0.03
2018 Jan 09.856±0.008 B= 22.05±0.01
2018 Jan 09.872±0.008 V= 21.98±0.03
The optical light curve evolution of the 2017 eruption has, to date, followed the light curve templates derived from the 2013, 2014, and 2015 eruptions (Darnley et al. 2016
. Therefore, we can conclude that the eruption occurred at 2017 Dec 31.3±0.1 UT. As such, these observations were taken approximately 9.5 days post-eruption.