Serendipitous new optical transient in the field of CSS081231:071126+440405
ATel #9328; D. Young (Far Reach Observatory / AAVSO), S. Kafka (AAVSO), M. Henze (CSIC-IEEC)
on 5 Aug 2016; 18:43 UT
Credential Certification: Martin Henze (henze@ice.cat)
Subjects: Optical, Transient
We report the discovery of an optical transient source at RA = 07:10:36.5, Dec = +44:06:48.07 (0.2 arcsec 1σ uncertainty; J2000). The source was detected on a total of 145 individual unfiltered 45 s exposures taken between 2016-02-12.04 UT (MJD 57430.04) and 2016-02-12.15 UT (MJD 57430.15). These data were obtained during the monitoring of the CSS081231:071126+440405 field (at RA = 42:14:50.8, 71:13:55.8) with the W80 Far Reach Observatory 0.4-m telescope equipped with a SBIG10XME CCD camera.
The new object was detected serendipitously near the edge of the field of view and is clearly visible on all individual images. Previous coverage of the same field, on 2015-12-10 UT, and a follow-up on 2016-02-14 UT did not show any object at this position down to a limit of V < 21.5 mag. There is nothing at this position in the VizieR catalogue data base within a radius of 15 arcsec.
At its maximum, the transient had a white light magnitude of 16.13±0.05 mag. During the course of the observations, the light curve of the transient declined smoothly, until it was detected at 17.69±0.03 mag at the end of the observing sequence. Therefore, the transient faded by about 1.6 magnitudes during the 158 minutes of imaging.
We encourage observers to check their archival (multiwavelength) data for additional detections of this rapidly evolving transient source.
