Optical brightening of VY Scl (GD 1662) seen concurrently with Einstein Probe flaring
ATel #16742; Thomas J. Maccarone (Texas Tech)
on 29 Jul 2024; 22:29 UT
Credential Certification: Tom Maccarone (thomas.maccarone@ttu.edu)
Subjects: Optical, X-ray, Binary, Cataclysmic Variable
In response to the discovery of increasing X-ray emission from the cataclysmic variable VY Scl = GD 1662 seen with the Einstein Probe by Li et al. (ATel #16741), I checked the ASAS-SN (Shappee et al. 2014,ApJ,788,48; Kochanek et al.2017,PASP, 129, 4502) photometry (linked below) of the object. The source was fainter than g=16.5 leading up to MJD 60511 (July 20, 2024). Over the next 4 days, it rose roughly linearly in time, reaching g of about 15.2 on July 24. The rise thus appears to be roughly coincident with the X-ray rise, and illustrates the value of sensitive all-sky monitors like Einstein Probe. Further detailed analysis from this source and future observations of other sources may yield important information about the X-ray/optical correlation in cataclysmic variables, which remains complicated and not extraordinarily well-understood.
Sky Patrol plot of last 20 days
