Representative pulse light curve
HT Cam super-ultra-bright outburst!
Finally a New Year Alert!!!
H. Itoh (Tokyo, Japan) reports that HT Cam (a ultra short-period CV; also renowned for its infrequent very brief outbursts) is undergoing an unprecedentedly bright outburst!! All sorts of observations (time-resolved continous photometry, spectroscopy, X-ray observation etc.) are MOST URGENTLY needed. The object is currently the top priority target of the VSNET campaign. Please keep us informed of the progress of your observation!
Visual magnitude estimates by VSOLJ members
object YYYYMMDD(UT) mag code CAMHT 20011229.680 122 Ioh.VSOLJ CAMHT 20011229.710 123 Ioh.VSOLJ CAMHT 20011229.833 122 Ioh.VSOLJCoordinates:
075701.3 +630600 (2000.0) RXJ0757.0+6306 18.2 CV 075700.4 +630601 (2000.0) 1RXS_J075700.5+630602 0.152 0.79 0.43 075701.2 +630600 (2000.0) CAMHT XM 17.2 (1.4) B - - -
Arto Oksanen has reported the following magnitude:
we observed HT Cam with Harri Hyvonen here at Nyrola under very bad conditions. Not much light curve but the unfiltered maginitude was:
CAMHT 20011230.9 15.7C AOk
HT Cam: very strong modulation!!
We have partly analyzed the Kyoto and RIKEN (Torii-san) data. The initial result is surprizing.
Superimposed on the decay, as inferred from visual and other observations, there exist *very strong* (0.4 mag or even larger) short-term modulations. Although exact identification requires further analysis (of the full-night data) and period analysis, the modulations seem to be somehow related to the 8.5-min period reported by Tovmassian. This finding may be indicative of the (possibly transient) IP (intermediate polar) nature of this object. [Note, however, optical photometry during an outburst of DO Dra, did show a similar (lower amplitude) periodicity which does not agree with the spin period].
The large-amplitude short-term modulations are quite unlike any modulations seen during an outburst of any CV. The characteristics are even drastically different from that reportd by Gary W. Billings (vsnet-alert 6953) less than 0.5 d ago! Observers are strongly requested to continue observing this object as intensively as possible, since we may have witnessed a short period of unexpectedly intensive avtivity of this CV.
VSNET Collaboration team
Correction! The period seems to be close to 8 min. [Not likely two-pole accretion].
We have put a representative pulse light curve at:
VSNET Collaboration team
Finding chart provided by Tovmassian
Link to the paper Link to the paper (PDF)
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