Central Bureau for Astronomical Telegrams

CBAT "Transient Object Followup Reports"

TCP J20190290+3159170

TCP J20190290+3159170   2020 03 05.8004*  20 19 02.90 +31 59 17.0  11.5 U             Cyg       9 0

2020 03 05.800

Discovered by Yukio Sakurai, Mito, Ibaragi-ken, Japan, who found this star on three frames (limit mag.= 12.5) taken with Nikon D7100 digital camera + 180-mm f/2.8 lens, who writes nothing is visible at the discovery position on three frames taken on 2020 March 2.802 UT by same instrument under the limiting mag.= 12.5. Sakurai writes there is a faint star (mag.< 15) at this location on DSS.

2020 03 4.0095

Images of this region were obtained on 2020-03-4.0095 UT (1.8 days prior to discovery) in the course of the NWW survey (2014ASPC..490..395S) using a 135mm f/2.0 lens + SBIG ST-8300M CCD. At that time, nothing was visible at the transient position down to a limiting magnitude of 13.5 (unfiltered with V zero-point). -- Kirill Sokolovsky, Stanislav Korotkiy

2020 03 05.0212

Correction: the latest NMW survey images of the field were obtained on 2020-03-05.0212 UT (0.78 days = 18.7 hours prior to discovery). At that time, the transient was not detected down to a limiting magnitude of 13.2 (unfiltered with V zero-point). -- Kirill Sokolovsky, Stanislav Korotkiy

2020 03 05.800

The star 2MASS J20190288+3159201 (r=15.4 in Pan-STARRS1; 20:19:02.90 +31:59:19.9 J2000 Gaia DR2) located 2.9" from the reported position of the transient is very likely a UV Ceti type variable. 2MASS color J-K=0.86+/-0.03 and Gaia parallax 11.05+/-0.04 mas suggest the object is an M dwarf. It is listed as variable in Gaia DR2 and its Gaia lightcurve ( http://scan.sai.msu.ru/~kirx/img/2054282552752609152.png ) shows outlier points that might be flares. The object is also listed as "dubious" in the ATLAS catalog of candidate variable stars (2018AJ....156..241H). -- Kirill Sokolovsky

2020 03 07.0989

Nothing is visible at the reported transient position down to CV=13.2 on new NMW survey images obtained at 2020-03-07.0989 UT. This is consistent with the interpretation of the transient as a UV Ceti type flare. The WCS-calibrated FITS images are available at http://scan.sai.msu.ru/~kirx/img/TCPJ20190290+3159170/ -- Kirill Sokolovsky, Stanislav Korotkiy