TCP J20225930+5239030: new transient (12.2 mag) in Cygnus

TCP J20225930+5239030 (UG:)

Spectroscopy, precise astrometry, and multiband as well as time-resolved photometry are urgently required.

Discovery details:
R.A. 20h22m59.30s, Decl. +52°39'03.0" (J2000.0)
2019 July 7.6524 UT, 12.2 mag (CCD, unfiltered)
Discoverer: Yuji Nakamura (Kameyama, Mie, Japan)

2019 07 07.6524 UT
Yuji Nakamura, Kameyama, Mie, Japan, reports his discovery of this TCP (mag 12.2) in Cyg on a CCD frame taken on 2019 Jul 07.6524 UT (limiting mag 13.0, exposure time 15s) using a 135mm F4.0 lens. The object was not shown on a frame taken on 2019 Jul 04.5161 UT (limiting mag 13.0).

2019 07 08.25 UT
The likely (blue) progenitor is USNO-B1.0 1426-0409109 with Gaia DR2 position end figures 59.369s, 05.48" (equinox J2000.0, epoch 2015.5, Gmag. 20.08, parallax 0.9657 ± 0.5002 mas). Other designations are GSC2.3 N2H3009280 (Fmag. 19.70, Bjmag. 19.95), PSO J202259.394+523905.824 (gmag. 19.93, rmag. 19.95), WD J202259.39+523905.61; a fainter Gaia DR2 source (Gmag. 21.10) is 0.9" to the NE. No outbursts were recorded by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) between 2015 March 2 and 2019 July 6; complete light curve at https://asas-sn.osu.edu/light_curves/194cc108-7b48-40a9-9adc-cd658bdd62…. The transient is probably a dwarf nova outburst with an amplitude of more than 7 magnitudes (WZ Sge type?). Spectroscopy as well as multiband and time-resolved photometry are strongly recommended. --- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J20225930+5239030.html

Clear skies,
Patrick