[vsnet-alert 23123] TCP J18325790-1642211: new transient (12.5 mag) in Sagittarius

Wed Apr 3 06:23:47 JST 2019

TCP J18325790-1642211

Discovery details:
R.A. 18h32m57.90s, Decl. -16°42'21.1" (J2000.0)
2019 Apr. 2.7544 UT, 12.5 mag (CCD, unfiltered)
Discoverer: Tadashi Kojima (Gunma-ken, Japan)

2019 04 02.754 UT
Discovered by T. Kojima, Gunma-ken, Japan, on three
frames with five second exposure using Canon EOS 6D
digital camera + 200-mm f/3.2 lens under the limiting
mag = 14.2, who writes nothing is visible at this
location on two frames taken on 2019 March 16 and
April 1 UT with limit mag.= 13s.

2019 04 02.85 UT
There is a red star 1.6" south of the transient's
reported position with Gaia DR2 position end figures
57.892s, 22.67" (equinox J2000.0, epoch 2015.5;
Gmag. 15.17). Other designations are
USNO-A2.0 0675-26976582 (Bmag. 17.6, Rmag. 15.6),
USNO-B1.0 0732-0651565, GSC2.3 SA79039038 (Vmag. 15.75,
Fmag. 15.07, Bjmag. 17.80), UCAC4 367-131021,
CMC15 J183257.8-164222, 2MASS J18325789-1642225,
UGPS J183257.89-164222.6.
According to recent ASAS-SN Sky Patrol (Shappee et al.
2014ApJ...788...48S and Kochanek et al. 2017PASP..
129j4502K) observations the current brightening began
around 2019 March 29; complete light curve at
https://asas-sn.osu.edu/light_curves/2207db5c-b277-44d0-af82-948b0feee86c
--- Patrick Schmeer (Saarbrücken-Bischmisheim, Germany)

http://www.cbat.eps.harvard.edu/unconf/followups/J18325790-1642211.html

Type unknown. Symbiotic variable star? Microlensing
event??

Spectroscopy, precise astrometry, and multiband
photometry are urgently required.

Clear skies,
Patrick