H-band detection of MASTER OT J004207.99+405501
ATel #7555; I. A. Steele, S. C. Williams, M. J. Darnley, M. F. Bode, R. M. Barnsley, R. J. Smith, H. E. Jermak (Liverpool John Moores University)
on 23 May 2015; 15:34 UT
Credential Certification: Matt Darnley (M.J.Darnley@ljmu.ac.uk)
The 2015 M31 stellar merger candidate (M31N 2015-01a / M31LRN 2015) was discovered by MASTER on 2015 Jan 13 (ATel #6911; see also Williams et al. 2015, ATel #6924, #6941, #6951, #6985, #7150, #7173, #7208, #7236, #7272, #7468, #7485) and recently reported (2015 May 15) as now being optically faint (I>21 - ATel #7537).
We obtained H-band imaging of the source on 2015 May 23 at 4:40UT with the new IO:I infrared imager on the 2.0 metre Liverpool Telescope (Steele et al. 2004), La Palma.
We clearly detect the source in a total exposure time of 180 seconds. Calibration with respect to 4 nearby 2MASS sources gives a preliminary magnitude estimate of H=16.0 ± 0.2 and implying I-H>5.
