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[vsnet-campaign-news 74] AstroAlert: V1363 Cyg brightening?
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Possible Brightening of the Unusual Cataclysmic Variable
V1363 Cygni
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According to AAVSO News Flash No. 793, the peculiar cataclysmic variable
(formerlly regareded as an Z Cam star, but its behavior is very different
from those of ordinary Z Cam stars) V1363 Cyg may be brightening.
CCD observation by Diethelm recoreded the object at 15.41 on June 4.9974 UT.
The object has been in its extended low state for years long.
Confirmation of the brightening, and subsequent detailed observations
are very strongly encouraged.
According to the discovery paper (Ric. Astr. Vol. 8, No. 10), V1363 Cyg
showed very peculiar behavior unlike other dwarf novae.
JD magnitude
(+2400000)
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around 32400: fainter than 17.5
around 32600: observed at 13-14 for about 40 days
then faded again to 16-<17.5
32950: started to brighten slowly
33000-33200: 14-15 mag
then slowly faded to mag 17 around 33600
33980: started to brighten, reaching a maxium of 13.5 around
34000
34100: 15-16 mag
34150: 13.5, then faded to
around 34200: 14-14.5
34220: faded further to mag 16
34230: brightened again to mag 14
then faded very slowly to mag 18 around 35000
From the time-scale of variations, the object looks like an anti-dwarf
nova (like MV Lyr and KR Aur) rather than usual Z Cam stars. Spectroscopic
observation by Bruch and Schimpke 1992 (A&AS 93, 419) confirmed its
cataclysmic nature. Recent faint state of this object is remniscent of
the "superminimum" of MV Lyr. The ROSAT Bright Source RX J2006.2+2342 is
likely to be identified with this cataclysmic variable. Close follow-up
observations are urged to see if the star may return to its active state
again.
V1363 Cyg is located at: 20h 06m 11s.58, +33o 42' 37".7 (J2000.0)
Information on VSNET:
http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v1363cyg.html
We have been undertaking on photometric campaigns on several super-
outbursting dwarf novae and peculiar variable stars. News and call for
observations on these objects will be issued on our regular weekly
"News from VSNET" bulletins. Those who immediately need information
should make an access to the VSNET website, and click on VSNET campaign
list.
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VSNET (Variable Star Network) is an international variable star observing
network, covering various areas of novae, supernovae, cataclysmic variables
(CVs), X-ray transients, and other classical eruptive, pulsating, and
eclipsing variables. VSNET is one of invited contributing organizations
to the SkyPub AstroAlert system.
VSNET Home Page: http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/
CCD observations of such targets are a relatively easy task for a 20-40cm
telescope; simply take as many CCD frames (with exposure times 10-30 sec)
as possible, spanning several hours per night. The only requirements are
the weather and your patience! If you need more help on the observing
technique, please feel free to ask on the vsnet-campaign list.
We would sincerely appreciate volunteers who would join the VSNET
Collaboration team to study the wonders of these exotic variable stars.
To join the VSNET campaign collaborative list, send an e-mail to
vsnet-adm@kusastro.kyoto-u.ac.jp (VSNET administrator)
with a line "SUBSCRIBE vsnet-campaign." or your comment to join the
collaboration team.
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