DW Cnc : Curious short-term variations
M. Reszelski reported a possible brightening to 14.5mag of this
poorly studied cataclysmic variable on February 18. This indicates
an outburst occurred, but there was no previous firm faint state
observation
(vsnet-campaign-dn 514,
527).
T. Vanmunster mentioned the object is always around 14.5+/- 0.5 mag,
and this activity may not be a genuine outburst
(vsnet-campaign-dn 531).
The Ouda team detected short-term variations whose amplitudes are
typically 0.3mag and period slightly shorter than 0.03day. T. Kato
reported that the period may reflect either the spin period of an
intermediate polar, or the orbital/superhump period of an
ultrashort-period binary
(vsnet-campaign 815,
816).
R. Novak sent his data to the Kyoto team. His data confirmed the
similar periodicity previously reported from the Kyoto and Ouda data.
On March 20, T. Kato reported that the combined data set shows
0.0275 day or its double periodicity
(vsnet-campaign 818).
On March 22, he again reported that the data including the additional
one show a very gradual fading trend (0.04 mag/d) which may resemble
those of slowly fading plateau of ER UMa stars. The period analysis
yielded multiple period candidates at 0.0756 d, 0.0536 d, 0.0488 d,
and 0.0276 d. He noticed that there may be a hint of beats between
these periods, but if any shorter one of them is a superhump/orbital
period, this system may be an extremely rare system close to the CV
period minimum, or below the period
(vsnet-campaign 822).
The combined data showed 0.053 and 0.027 day period, but their
confidence level is low
(vsnet-campaign 835).
R. Novak's data on mid-April showed strong modulations with a period of
0.029 d
(vsnet-campaign-dn 655).
M. Uemura reported that the object has remained the brightness over
one month. The time-series monitoring campaign by the Kyoto team,
R. Novak, and J. Pietz yields the periodicity of 0.04855 or 0.0268 d.
(vsnet-campaign 862).
The object was still in bright state in the latter half of 2001
(vsnet-campaign-dn 1874).
Other related articles:
vsnet-campaign-dn 596,
602,
605,
621,
624,
650,
652,
661,
vsnet-campaign-nl 52,
vsnet-campaign 824,
834,
820,
825
Links:
Sequence and chart reported by B. Sumner:
http://joevp.20m.com/cgi-bin/i/charts/hscharts/South_up/Cnc_DW_sxn.jpg,
ftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/dwcnc.dat
Data in Amateur Data Archvie:
http://ada.astronomy.cz
