Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

PNV J00422413+4111549

PNV J00422413+4111549   2011 06 07.418 *  00 42 24.13 +41 11 54.9  18.3 R  228W 255S  M31       9 0 

2011 06 07.107

Detected with the Swift UVOT in five UVW1 filter exposures as bright variable source at position RA=00h42m24.14s, Dec=41d11'54.8" (J2000, position error 0.2"). Between the first and second exposure the UV brightness increased by 0.5 mag to 15.72 mag and then dropped exponentially in the following exposures by 1.8 mag within 1/3 of a day. The optical detection was at the end of this outburst UV light curve. Could either be a very fast nova in M 31 or a flaring foreground star. For details see Atel 3446 by Pietsch, Henze and Hornoch.