Potential CV association for Swift J073006.8-193709
ATel #15411; Muryel Guolo (JHU), Suvi Gezari (STScI/JHU)
on 1 Jun 2022; 16:29 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Suvi Gezari (suvi@astro.umd.edu)
Subjects: Optical, X-ray, Cataclysmic Variable, Variables
Referred to by ATel #: 15412
Following the report on the discovery of Swift J073006.8-193709 by Evans & Malesani (ATEL #15404), we searched for a recent optical counterpart of this X-ray transient discovered on MJD 59729.
Using the ATLAS forced photometry server (Tonry et al. 2018) we detected a recent (Jan-Feb 2022) large-amplitude (> 3 mag) optical transient consistent with the reported position (RA: 112.5284, Dec: -19.6193). The transient was detected above ATLAS' limiting magnitude (~ 19.7 mag) for ~ 22 days, from MJD 59600 to MJD 59622, peaking at an o-band magnitude of 16.7 mag on MJD 59604. A plot of the ATLAS light curve is available below.
The Zwicky Transient Facility (ZTF) was offline for most of the bright portion of the transient. The ZTF forced photometry server (Masci et al. 2018) returns detections only on MJD 59624, with r and g band magnitudes of 18.5 and 18.8 mag, respectively.
The Swift J073006.8-193709 X-ray position is 1.42 arcseconds from ASASSN-20kt, which is a cataclysmic variable (CV) candidate that was detected by ASASSN on 25 August 2020 (Shappee et al. 2014).
These two optical outbursts in August 2022 and January 2022 together with the outburst detected by Pan-STARRS1 in Jun 2013 reported by ATEL #15404 suggests this X-ray transient is an outbursting CV. Photometric and spectroscopic follow up are encouraged for further confirmation on the nature of this source.
ATLAS light curve
