[vsnet-alert 17479] MASTER OT J172758.09+380021.5 outburst

Denis Denisenko d.v.denisenko at gmail.com
Thu Jul 10 21:07:25 JST 2014


Bradford Robotic Telescope has caught an outburst of the dwarf nova in
Hercules MASTER OT J172758.09+380021.5 with unknown orbital period. It
was discovered as a bright transient on 2014 Jan. 04 (see ATel #5724,
http://www.astronomerstelegram.org/?read=5724 for more details) when
this part of sky was poorly located for observations. The new variable
has been monitored with BRT since April, and it was finally detected
in outburst last night.

MASTER OT J172758.09+380021.5 = SDSS J172758.13+380022.4
  20040503.169   177CV  BRT
  20040512.146   180CV  BRT
  20040520.132   176CV  BRT
  20040528.098   185CV  BRT
  20040603.099   177CV  BRT
  20040609.074   184CV  BRT
  20040625.038   184CV  BRT
  20040709.997  15.43CV BRT  Outburst

Nearby TYC 3086-1594-1 (17 28 02.08 +37 59 29.1 V=11.82 B=12.33) was
used as a reference star.

It is not clear whether this is a normal outburst or a superoutburst.
Probably the former, since the discovery outburst was brighter
(14.3C). In any case, time series are encouraged since the object is
now favorably located in the sky, being visible almost the whole
night.

Catalina light curve:
http://nesssi.cacr.caltech.edu/cgi-bin/getcssconedb_id.cgi?ID=1138075042858&OUT=csv&SHORT=short&PLOT=plot
The object was detected in outburst by Sloan Sky Survey, so SDSS
magnitudes can not be used for the orbital period estimation:
SDSS J172758.13+380022.4 u=15.62 g=15.35 r=15.55 i=15.71 z=15.84
http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237665584870916221

Denis Denisenko
Member of MASTER team at SAI MSU


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