[vsnet-alert 13679] New CV in Camelopardalis (ATel 3651)

[Denis Denisenko]

J. Vinko et al. report in Astronomer's Telegram (ATel) #3651 on the 
discovery by ROTSE-IIIb of a probable new cataclysmic variable in 
Camelopardalis which was ~14m three weeks ago (on Aug. 30) and faded to 
~16.1 by Sep. 14.

The new object is designated ROTSE3_J034450.8+683753 by the authors, and 
the coordinates are reported to be uncertain by ~1":

03 44 50.8 +68 37 53

The full text of ATel follows.  Please note that the "faint USNO-B 
source" mentioned in the Telegram is formally 9" away (due North) from 
the new variable, thus likely not related to it.  (I would even say it 
is definitely not related to the new CV, being too red).  Unfortunately 
the star is not present either in GALEX UV or in 2MASS IR catalogs.  But 
there is indeed some faint blue star marginally visible on the POSS-II 
plates at the reported position.  I have uploaded 10'x10' color-combined 
(BRIR) chart centered at new variable with its position marked with 
dashes here: http://hea.iki.rssi.ru/~denis/J0344+6837-BRIR.jpg

The star appears to have at least a 7-mag outburst amplitude.  Taken 
together with a long outburst duration it might suggest an UGWZ 
superoutburst with possible rebrightenings.  Thus, it may be worth of 
the follow-up, even though it's been monitored with ROTSE-III telescopes.

Denis Denisenko

http://www.astronomerstelegram.org/?read=3651

J. Vinko (University of Szeged) et al. on behalf of the ROTSE collaboration

We report the discovery of a new transient (mag ~14.9) in unfiltered 
images taken on Aug. 29.39 UT with the 0.45-m ROTSE-IIIb telescope at 
McDonald Observatory. The transient has brightened to mag ~14.0 on Aug. 
30.42 then started to decay gradually in the following weeks with mag 
~15.3 on Sep. 7.38 and mag ~16.1 on Sep. 14.37. The new object is 
located at R.A. = 03h44m50s.76, Decl. = +68o37'52".9 (equinox 2000.0; 
uncertainty about 1"). A finding chart for the object can be found at 
website URL: 
<http://www.rotse.net/rsvp/j034450.8+683753/ROTSE3_J034450.8+683753.jpg> 
http://www.rotse.net/rsvp/j034450.8+683753/ROTSE3_J034450.8+683753.jpg A 
faint source is present at the position of the transient on the POSS-II 
images with USNO B1.0 magnitudes R=19.77 and I=18.85. A spectrum 
obtained with the 9.2-m Hobby-Eberly Telescope (+Marcario Low-Resolution 
Spectrograph, R ~ 600) by J. Caldwell on 2011. Sept. 1.46 UT shows 
narrow absorption features, including Na-D, H-beta and H-gamma at zero 
redshift, superimposed on a smooth blue continuum. H-alpha is filled up 
by an emission component, but does not extend above the continuum. A 
second spectrum obtained on Sept. 17.42 UT by S. Rostopchin has the same 
overall appearance, but with flatter, redder continuum slope. The 
spectroscopic observations together with the identification of a 
stellar-like source at this position, suggest that the transient is 
galactic, probably an outburst of a cataclysmic variable. Monitoring 
with the ROTSE-III telescopes is continuing.