Rare outburst of OY Car Rare outburst of OY Car The UGSU type variable star OY Car is in outburst this evening
OY Car 1997 Mar 25.424 UT 11.7
25.454 11.6
Also, HL CMa at it again
HL CMa 1997 Mar 25.434 UT 11.0
Full moon present.
Regards,
Michael Mattiazzo,
Adelaide, South Australia
mmatti@dedset.net.au
I am looking for confirmation of the AAVSO report (AAVSO News Flash #132) that the SU UMa-type dwarf nova OY Car (RA=10:06:22.3, DEC=-70:14:05.0, epoch 2000) is in outburst (V<12). If the outburst is confirmed, an EUVE Target of Opportunity observation will begin as early as DOY 85 22 UT (in less than 24 hrs). Please send visual magnitude estimates to the address below asap. If the source is in outburst, regular monitoring throughout the outburst would be of great value.
Regards,
------------------------------------------------------------------------- | Christopher W. Mauche Phone: (510) 422-7017 | | Lawrence Livermore Nat'l Lab. Fax: (510) 423-7228 | | L-41, P.O. Box 808 e-mail: mauche@cygnus.llnl.gov | | Livermore, CA 94550 or: mauche@llnl.gov | -------------------------------------------------------------------------
One estimate of OY Carinae, under difficult conditions:
OY CAR March 26.802 UT 11.1 HJN
Thank goodness the heavy clouds have gone, but there is till a lot of thin cloud - and the Moon!
Jan Hers, Sedgefield, South Africa.
Following the initial alert by Michael Mattiazzo (vsnet-alert 802), following observations have been reported to vsnet-alert and vsnet-obs.
YYMMDD(UT) mag code 970312.497 <127 MKA 970316.433 <127 MKA 970325.424 117 MKA 970325.453 116 MKA 970325.562 116 MKA 970326.417 114 MKA 970326.458 115 MKA 970326.500 116 MKA 970326.542 115 MKA 970326.801 111 HJNJudging from the brightness and duration, the present outburst may well be a superoutburst, since its last one in 1995 October - November.
OY Car is one of the most well-known eclipsing SU UMa-type dwarf novae, which have been and will be teaching us much about the physical processes going in superoutbursting dwarf novae. OY Car has played an important role in this field [1,2,3].
[1] J. H. Wood et al., 1989, ApJ 341, 974
[2] F. V. Hessman et al., 1992, AsAp 263, 147
(OY Carinae: the secrets of the super-humps revealed)
[3] I. Billington et al., 1996, MNRAS, 279, 1274 and references therein
I would also like to urge visual (and CCD, of course) observers to record
spectacular eclipses (together with possible
superhumps) of this short-period
cataclysmic binary. A good northern example may be found at
(http://www.kusastro.kyoto-u.ac.jp/vsnet/DNe/htcas.html).
According to [1], eclipse are expected to occur:
HJED = 2443993.553691 + 0.0631209295 E
+/-50 +/-20
Regards,
HT Cas
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