1RXS J231935.0+364705

New Cataclysmic Variable in Andromeda 1RXS J231935.0+364705

This page is an addendum to the Astronomer's Telegram ATel 2282 published on 2009 November 5.

Light curve from the archival NSVS (ROTSE-1) images

Variability of 1RXS J231935.0+364705 was found on December 8th, 2007 in course of search for the optical identifications of ROSAT sources. The following archival light curve was obtained by ROTSE-1 experiment during May 1999 - January 2000:

Note the long outburst (possibly a superoutburst) on November 9, 1999 (JD=2451492)!

Comparison of POSS-II IR plate and 2MASS J image

NSVS 9022680 is actually a blend of two stars separated by 18.5". It is the fainter (north-western) star of the two which is variable.

USNO-A2.0 1200-19824206  23 19 36.07 +36 47 00.8  R=17.6  B=17.6
USNO-A2.0 1200-19824318  23 19 37.00 +36 46 45.5  R=14.2  B=15.2

10'x9' DSS finder chart

The color image below was combined using the POSS-II IR plate from Aug. 28, 1995 as Red channel, R plate of July 14, 1989 as Green channel and B plate of Aug. 22, 1995 as Blue channel. Star was in outburst on DSS infrared plate but in quiescence on blue plate taken just 6 days earlier - this is why the peculiar color.

Position of variable is marked with dashes

USNO-B1.0 1267-0564384
23 19 36.06 +36 47 00.3  pmRA=-4  pmDE=-14  B1=17.73 R1=17.73 B2=18.66 R2=17.73 I=13.63

Note: the real range of variability may be well beyond the 17.6-13.6 values specified on the chart. In particular, star can fade down to ~19m at the minimum!

Bradford Robotic Telescope observations

The following photometry was obtained with BRT in October-November 2009 using R=14.4, B=15.2 as a comparison star:

Time (JD)    YYYY-MM-DD.ddd  R mag
----------------------------------
2455121.542  2009 10 17.042  18.74
2455127.552  2009 10 23.052  18.96
2455140.522  2009 11 05.022  14.48  Outburst!!!

Our previous Telegrams

ATel #2014: Optical variability of 1RXS J173006.4+033813 by D.V. Denisenko, T.V. Kryachko, B.L. Satovskiy (2009 Apr. 16)
ATel #1640: New cataclysmic variable 1RXS J180834.7+101041 by D.V. Denisenko, T.V. Kryachko, B.L. Satovskiy (2008 July 31)
ATel #652: Discovery of deep eclipses in the cataclysmic variable 1RXS J020929.0+283243 by D.V. Denisenko, R.A. Sunyaev, Z. Aslan, I. Khamitov (2005 Nov. 8)

New Variable Stars by Denis Denisenko