Discovery of an Optical Transient in M82
ATel #1501; M. M. Kasliwal, E. O. Ofek, S. B. Cenko, A. Rau, R. Quimby, S. R. Kulkarni (Caltech)
on 30 Apr 2008; 23:56 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Mansi Manoj Kasliwal (mansi@astro.caltech.edu)
Subjects: Infra-Red, Optical, Cataclysmic Variable, Nova, Supernovae, Transient
On UT 2008 Apr 29.24, the robotic Palomar 60-inch discovered an optical transient, 165" W and 64" S of the center of M82 at RA(J2000) = 09:55:21.0, Dec(J2000) = +69:39:42. P60-M82-080429 had an apparent g-band magnitude of 20.3 +/- 0.1. Assuming a distance modulus of 27.77 (B. Tully, pers. comm.) and since we are not correcting for extinction here, the absolute magnitude is brighter than -7.5. This source is also detected on : Apr 28.18, g ~ 20.6; Apr 27.30, g ~ 20.7; Apr 26.18, g ~ 20.5; Apr 25.19, g ~ 20.6. Nothing was seen at this position prior to Apr 25 to a limiting magnitude of 21.5. Follow-up with Wide Field Infrared Camera on the Palomar 200-inch shows an infrared counterpart, K = 18.7 +/- 0.2. A SIMBAD query suggests a globular cluster near this position and there is no catalogued counterpart in SDSS DR6. We are pursuing and encourage multi-band photometric and spectroscopic followup.
