TCP J15360165-1642561: likely dwarf nova outburst (13.3 mag) in Libra

Affiliation
Association Francaise des Observateurs d'Etoiles Variables (AFOEV)
Tue, 01/01/2019 - 11:11

TCP J15360165-164256 (UG)

Discovery details:
R.A. 15h36m01.65s, Decl. -16°42'56.1" (J2000.0)
2018 Dec. 31.8574 UT, 13.3 mag (CCD, unfiltered)
Discoverer: Hideo Nishimura (Shizuoka-ken, Japan)

2018 12 31.857 UT
Discovered by H. Nishimura, Shizuoka-ken, Japan, on three frames with 30 second exposure using Canon EOS 6D digital camera + 200-mm f/3.2 lens under the limiting mag = 15, who writes nothing is visible at this location on a frame taken on 2018 Dec. 29.861 UT with limit mag.= 15 and a star (mag = 20) is present at this location on DSS.

2019 01 01.37 UT
A progenitor candidate from Gaia DR2 is 3" away at R.A. 15h36m01.725s, Decl. -16°42'58.88" (equinox J2000.0, epoch 2015.5; Gmag. 19.75). Other designations are ASAS J153601-1643.0 (single outburst on 2004 April 18.28 UT, Vmag. = 14.3), CSS_J153601.6-164301 (Vmag. range 14.8 [single outburst on 2007 March 14.49 UT] - 20.7) = SSS_J153601.7-164259 (Vmag. range ~17.6-20.1), USNO-B1.0 0732-0339455 (Bmag. 20.83, Rmag. 19.24), GSC2.3 S90F008636 (Fmag. 19.23, Bjmag. 19.86), PSO J153601.737-164258.755 (blue star, gmag. 20.11, rmag. 19.97), WISE J153601.75-164258.9, GALEX J153601.7-164300 (fuv_mag. 19.64, nuv_mag. 19.69), etc. No outbursts of this object were detected by the ASAS-SN Sky Patrol (Shappee et al. 2014ApJ...788...48S and Kochanek et al. 2017PASP..129j4502K) between 2012 February 27 and 2018 September 21 (no observations since then); complete light curve at
https://asas-sn.osu.edu/light_curves/b4c4e9fc-8a4c-4b79-a7c8-a55666c033…
This is probably a dwarf nova with at least three recorded outbursts.
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J15360165-1642561.html

*** Precise astrometry, spectroscopy, and multiband/time-resolved photometry are urgently required. ***

Happy New Year and clear skies!
Patrick