[vsnet-alert 15809] New bright CV in Vulpecula MASTER OT J212624.16+253827.2

[Denis Denisenko]

New bright cataclysmic variable MASTER OT J212624.16+253827.2 was just
discovered and published in Astronomer's Telegram ATel #5111,
<http://www.astronomerstelegram.org/?read=5111>. The discovery
magnitude is 14.2m which places it in Top 10% of MASTER CVs.

Moreover, previous outbursts were found in the archival data of MASTER
survey, one of them (on 2012 Dec. 21) was even brighter:

MASTER OT J212624.16+253827.2
  20120622.734  14.17  MASTER-Amur
  20120624.834  14.82  MASTER-Kislovodsk
  20120624.882  14.86  MASTER-Kislovodsk
  20121221.466  13.73  MASTER-Amur
  20121223.405  13.93  MASTER-Amur
  20130329.836  14.85  MASTER-Amur
  20130606.634  14.16  MASTER-Amur
  20130606.666  14.06  MASTER-Amur
  20130606.667  14.19  MASTER-Amur

The object is identical to SDSS J212624.13+253826.9 which was caught
in outburst by Sloan survey on ObsDate=2009.8783: u=15.02 g=14.51
r=14.67 i=14.81 z=14.93
Chart can be found at
http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237680474971374241
(referred to as SDSS J212624.12+253826.8 with strange values of
magnitudes: u=19.80 g=19.27 r=18.79 i=18.46 z=18.16).

Other IDs:
USNO-A2.0 1125-18372982 (21 26 24.20 +25 38 28.4 B=18.5 R=18.3)
USNO-B1.0 1156-0515545 (21 26 24.151 +25 38 27.23 pmRA=-14 pmDE=-24
B1=19.27 R1=18.73 B2=18.75 R2=19.54 I=18.18)
GALEX J212624.2+253827 (NUV=20.81+/-0.26)

Since the outburst amplitude is ~5m, the object is likely a new
UGSU-type variable in superoutburst. Time resolved photometry is
definitely encouraged.

Discovery and reference images:
http://master.sai.msu.ru/static/OT/212624.16253827.2.png

The new variable is located 73.5" south-south-east of TYC 2191-1089-1
(B=11.82, V=11.72) which shows marginal variability in NSVS data:
NSVS 8757477
Median ROTSE Mag = 12.343
Mag Scatter = 0.034
Median Error = 0.024
http://skydot.lanl.gov/nsvs/star.php?num=8757477&mask=32004

Denis Denisenko
Member of MASTER team at SAI MSU