Swift UVOT detection of the recurrent nova M31N 1963-09c during the 2015 eruption
ATel #8235; M. Henze (IEEC/CSIC), S. C. Williams (LJMU), M. J. Darnley (LJMU), A. W. Shafter (SDSU), K. Hornoch (Astronomical Institute, Ondrejov, Czech Republic)
on 1 Nov 2015; 22:13 UT
Credential Certification: Martin Henze (henze@ice.cat)
Subjects: Ultra-Violet, Nova
We report the detection of the 2015 eruption of the recurrent nova M31N 1963-09c (ATels #8233,#8234) in observations obtained with the Swift Ultraviolet/Optical Telescope (UVOT). With only five years since the last eruption (ATel #3001) this nova has the second shortest recurrence time of any known recurrent nova (only surpassed by M31N 2008-12a; see Henze et al. 2015 and Shafter et al. 2015).
Immediately after the optical discovery we initiated a Swift UVOT monitoring programme that detected the nova on 2015-11-01.497 UT, only 1.5 days after discovery (ATel #8233). The source was clearly visible in the three UV filters with the following Vega magnitudes: uvw1 (central wavelength 260 nm) = 17.8±0.1 mag; uvw2 (193 nm) = 17.9±0.1 mag; uvm2 (225 nm) = 17.9±0.1 mag. The magnitudes are in the UVOT photometric system (Poole et al. 2008) and have not been corrected for extinction. Nothing is detected in 3 ks of Swift XRT exposure. We will continue to monitor the light curve to compare its evolution to the 2010 eruption (see ATel #3038 and Henze et al. 2014)
We wish to thank the Swift Team for making the ToO observations possible, in particular N. Gehrels, the duty scientists as well as the science planners.