CSS optical transients

ATel #1404; A. J. Drake, A. Mahabal, R. Williams, S. G. Djorgovski, M. J. Graham (Caltech); E. C. Beshore, S. M. Larson (LPL/UA); E. Christensen (Gemini Observatory)
on 2 Mar 2008; 20:39 UT
Credential Certification: Andrew J. Drake (ajd@cacr.caltech.edu)

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We have detected three optical transients in Catalina Sky Survey (CSS) images obtained at the Mt. Bigelow 0.7m Catalina Schmidt Telescope on 28 Feb - 02 Mar 2008 UT. The CSS discovery observations consist of four images spanning ~30 minutes. The transients were unresolved, and at the following J2000 coordinates:

CSS080228:044416-054730	2008-02-28 UT 04:06:23	RA 04:44:16.05	Dec 05:47:30.2	Mag 18.0
CSS080228:142427--063345	2008-02-28 UT 12:12:46	RA 14:24:26.63	Dec -06:33:44.8	Mag 18.7
CSS080302:145726-232348	2008-03-02 UT 11:54:23	RA 14:57:26.21	Dec 23:23:48.2	Mag 19

For finding charts and discovery images please see: http://voeventnet.caltech.edu/feeds/ATEL/CSS.

The first transient was not detected in the first image of the sequence. In the subsequent observations it was 17, 17.5 and 18th magnitude. This strongly suggests that it is flare star. In Palomar-Quest coadds the probable source star is seen at magnitude I ~21. The second transient was magnitude ~18.2 in CSS images from February 3 UT and 18.5 on February 19 UT. This may be a supernova or a flare from an AGN. The third transient is associated with galaxy 2MASX J14572647+2324051 (14h57m26.5s +23d24m05s, g ~ 17.2, r ~ 16.5) and is likely to be a supernova. The object is present in observations taken on UT dates February 8th and 18th but is not present on January 1st. This object is not present in DSS, Palomar-Quest and SDSS images covering this location. Photometric and spectroscopic follow-up is requested.

All stationary CSS optical transients are detected and published as VOEvents in real-time at http://voeventnet.org/feeds/Catalina.shtml and here http://voeventnet.caltech.edu/feeds/Catfeed.xml (RSS)