[vsnet-alert 17148] CSS J172038.7+183802 outburst (15.2m)

[Denis Denisenko]

MASTER-Amur robotic telescope has detected a bright outburst of this
dwarf nova in Hercules with unknown orbital period.

CSS J172038.7+183802 = CSS 090929:172039+183802
  20140403.774   154C   MASTER-Amur
  20140403.807   153C   MASTER-Amur
  20140403.835   152C   MASTER-Amur

Variability range in AAVSO VSX is 15.3-20.8 CV. Light curve from
Catalina Sky Survey:
http://nesssi.cacr.caltech.edu/catalina/20090929/909291180894139837p.html

This area of sky is not covered by SDSS, thus the color info is not
available. From the archival data the star appears to be a dwarf nova
of SU UMa type with normal outbursts to ~16m and brighter ones to
~15m. Current outburst is likely a superoutburst.

Object IDs in catalogs:
USNO-B1.0 1086-0273241 (17 20 38.687 +18 38 02.03 B1=19.86 R1=N/A
B2=19.92 R2=19.91 I=18.95)
GALEX J172038.7+183802 (FUV=20.31+/-0.16 NUV=20.25+/-0.10)

Denis Denisenko
Member of MASTER team at SAI MSU