[vsnet-alert 16697] New UGSU candidate MASTER OT J162323.48+782603.3 (13m)

[Denis Denisenko]

MASTER robotic telescopes network has discovered its brightest CV in
2.5 months - 13m dwarf nova in Ursa Minor which was listed in the
catalog of X-ray/radio associations as a 93% quasar, 1% galaxy and 1%
star, despite having a large proper motion (1" in 40 years) on Palomar
plates and in USNO-B1.0. The discovery has just been published in
Astronomer's Telegram ATel #5643,
http://www.astronomerstelegram.org/?read=5643

MASTER OT J162323.48+782603.3
  20131209.4951  13.16C  MASTER-Tunka
  20131209.4964  13.16C  MASTER-Tunka
  20131209.4977  13.20C  MASTER-Tunka
  20131209.5742  12.95C  MASTER-Tunka
  20131209.5757  13.03C  MASTER-Tunka

The star has brightened by 0.2m in 1.9 hr between the two triplets of
MASTER-Tunka images. Either the outburst is still growing, or there is
a large-amplitude superhumps (or both). Time-resolved photometry is
obviously required! The object is circumpolar for the Northern
hemisphere observers (but outside of Catalina Sky Survey coverage).

There were two previous outbursts observed by MASTER-Amur in 2012 (but
not detected as a transient):
  20120107.928    133C   MASTER-Amur
  20121119.551    133C   MASTER-Amur

Object IDs:
USNO-A2.0 1650-01856527 (16 23 23.60 +78 26 02.1 R=18.3 B=18.2)
USNO-B1.0 1684-0061530 (16 23 23.378 +78 26 03.56 pmRA=-10 pmDE=24
B1=18.19 R1=18.20 B2=19.14 R2=18.91 I=18.30)
SDSS J162323.38+782603.6 (u=18.62 g=18.37 r=18.37 i=18.28 z=17.91)
2MASS 16232331+7826031 (J=16.42+/-0.14 H=15.83+/-0.16 K=N/A)
GALEX J162323.3+782603 (FUV=19.63+/-0.09 NUV=19.20+/-0.05)
2RXP J162322.7+782559 (0.00726 cnts/s)

Denis Denisenko
Member of MASTER team at SAI MSU