[vsnet-alert 22912] TCP J15360165-1642561: likely dwarf nova outburst (13.3 mag) in Libra

Tue Jan 1 21:24:34 JST 2019

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-a55666c0338e
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