KWS pre-discovery observations of CSS160603:162117+441254 = 2MASS J16211735+4412541
Hiroyuki Maehara (Okayama Astrophysical Observatory, NAOJ)
I report pre-discovery observations of an outburst of CSS160603:162117+441254 = 2MASS J16211735+4412541 (Drake et al., ATel #9112) with the Kamogata-Kiso-Kyoto Wide-field Survey (KWS) imager (f.l. = 105-mm lens + SBIG ST-8XME CCD Camera). According to the KWS photometric database, the object was already in outburst at V=13.3 on 2016-06-01.616 (UT) and was also detected on 2016-06-02 and 2016-06-03 at V=13.1-13.2. The V-Ic color index of the object during the outburst is V-Ic ~ 1. The following table presents the preliminary photometry (and upper limit) of the object from the KWS database.
optical,cataclysmic variable,transient,variables