[vsnet-alert 13553] 1RXS J174320.1-042953 in a high state

[Denis Denisenko]

Dear all!

X-ray selected CV in Ophiuchus 1RXS J174320.1-042953 = RX J1743.3-0429 
(or simply J1743-0429) appears to be in a prolonged high state for about 
3 months now.  It was identified as a cataclysmic variable by myself and 
Kirill Sokolovsky about a year ago (see arxiv:1007.1798 and 
http://hea.iki.rssi.ru/~denis/CV-USNO.html for details), but no 
observations have been reported since then.  DSS plates and USNO-B1.0 
catalog show the range of variability to be around 15.1-18.1R with the 
star faint in 1982, 1984 and 1989 but bright in July 1954.  USNO-B1.0 
magnitudes are:

B1=16.12 R1=15.15 B2=18.95 R2=18.13 I=17.10

2MASS 17432029-0429569 magnitudes are:
J=14.811+/-0.036 H=14.367+/-0.044 K=14.173+/-0.062

CRTS data (A. Drake, private communication) are contaminated by the 
presence of a ~16m companion just 5.5" South of the variable and are not 
conclusive.  However, it appears that J1743-0429 was fainter than 17m in 
July 2010.  The recent observations with the Bradford Robotic Telescope 
show the star to be bright again, although fainter than in 1954:

J1743-0429    May 22.1270  16.15R
J1743-0429    Aug  4.0091  15.96R

In VSNET format:

1RXS J174320.1-042953

  YYYYMMDD(UT)   mag  observer
  20110522.127  16.15R (Bradford Robotic Telescope)
  20110804.009     15.96R (Bradford Robotic Telescope)

Most likely the object is a polar with interchanging low and high 
states, but it could also be a Z Cam variable currently at the 
standstill.  Time-resolved photometry is encouraged, as well as 
continued nightly monitoring.

I have created a preliminary chart with USNO-A2.0 Red magnitudes of 
several comparison stars labeled:

http://hea.iki.rssi.ru/~denis/J1743-0429-comps.gif

The field is rather crowded, but without any good reference stars in 
13-15.5m range.

Object is now conveniently located for observers in both hemispheres and 
can be a good target until SV Ari rises.  1RXS J174320.1-042953 is 
included into AAVSO VSX with AUID 000-BKC-297.

Best regards,

Denis
--
Denis V. Denisenko
Space Research Institute
Profsoyuznaya st., 84/32
117997, Moscow, Russia
denis at hea.iki.rssi.ru