Detection of the First Observed Outburst of DW Cancri
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Tim Crawford
Arch Cape Observatory, 79916 W. Beach Road, Arch Cape, OR 97102
David Boyd
5 Silver Lane, West Challow, Wantage, OX12 9TX, UK
Carlo Gualdoni
22100 Como, Italy
Tomas Gomez
Lira 8, 6-A, 28007 Madrid, Spain
Walter MacDonald II
P.O. Box142, Winchester, ON K0C 2K0, Canada
Arto Oksanen
Verkkoniementie 30, FI-40950 Muurame, Finland
Received April 27, 2007; revised January 4, 2008; accepted January 7, 2008
Abstract
Using data gathered by amateur astronomers from several nations, as
reported to the American Association of Variable Star Observers (AAVSO), the first
observed outburst of the intermediate polar DW Cancri was detected on January
25, 2007, at magnitude V ~11.36. This represented a brightening of ~4 magnitudes
from both recent measurements and long term average quiescence. The outburst
was of a relatively short duration, as measured from the first detection of the
outburst, showing a fading of ~2.25 magnitudes in ~27 hours, and another ~1.25
magnitudes within the next ~30 hours. Follow up photometric observations show
the asynchronous rotation period of the magnetic white dwarf star of this system
to be 38.6 minutes, in agreement with previous studies; a strong secondary signal
of ~73.7 minutes was also noted. As to whether or not the outburst was the result
of disk instabilities or caused by a mass transfer event, no conclusion could be
reached.
