August 6, 2018 : Further to AAVSO Alert Notice 640, the SU UMa-type dwarf nova VW Hyi is in outburst and is the subject of a multiwavelength campaign designed to detect possible radio emission during the outburst.
November 25, 2008
January 25, 2017: The beginning of the observing window for the Chandra TOO observations of the SU
UMa-type dwarf nova YZ Cnc that are the focus of AAVSO Alert Notice 565 and AAVSO Special Notice #427 has been delayed.
Principal Investigator Dr. Christian Knigge (University of Southampton) informs us that Chandra Mission Planning has informed him that the beginning of the Chandra-observable window for YZ Cnc has been delayed until 2017 February 5.
January 23, 2017: The observing campaign is continuing for the SU UMa-type dwarf nova YZ Cnc. In AAVSO Alert Notice 565, Dr. Christian Knigge (University of Southampton) and colleagues requested AAVSO coverage in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system was in a suitable outburst.
December 19, 2016: Dr. Christian Knigge (University of Southampton) and colleagues have requested AAVSO coverage of the SU UMa-type dwarf nova YZ Cnc in support of Chandra X-ray observations to be carried out via a Target of Opportunity (TOO) triggering when the system is in a suitable outburst.
YZ Cnc has normal outbursts about every 7-10 days, and superoutbursts about every 100-110 days. The astronomers are planning to use a superoutburst to trigger the TOO observations.
April 14, 2007
The cataclysmic variable star BZ UMa is currently experiencing an outburst which is peculiar for that star. Historically, BZ UMa has outbursts every 312 +/-114 days (although it has been much more regular in the past decade). These outbursts are similar to regular UGSU outbursts with a fast rise and a short decay over four days and are absent of any superhumps or other periodicity. However, no superoutbursts of the type also associated with UGSU stars have been detected in BZ UMa despite good observational coverage since 1972.
January 19, 2007
In AAVSO Special Notice #29, the wrong satellite was named as the source of observations being analyzed by Dr. Jeno Sokoloski. A correction published in Special Notice #30 was ambiguous. To clarify matters, below is the corrected full text of the AAVSO Special Notice #29. Please disregard Special Notice #30. We apologize for the error and confusion! -- Elizabeth Waagen
January 18, 2007
In AAVSO Special Notice #29, I said that Dr. Jeno Sokoloski was requesting our observing assistance on V550 Cyg in order to correlate her observations taken by ROSAT in the last few days. Since ROSAT ceased operating in 1999, I clearly mis-spoke! However, Dr. Sokoloski is using archival ROSAT data in her research on this star in addition to her recently-obtained observations. My apologies to Dr. Sokoloski for the error.
Elizabeth O. Waagen
January 18, 2007
Coordinates of V550 Cyg: RA = 20:05:05.2 Dec = +32:21:22 (2000.0)
November 8, 2006
Rod Stubbings has detected a bright outburst of the dwarf nova EG Aqr. This has been confirmed by Hiroyuki Maehara of the VSOLJ, at magnitude V=13.08. This object has not been in outburst in recent history (last outburst I see is 1951?), so monitoring and V-band time series are encouraged. Good charts and photometric sequence information is on the AAVSO website.
prepared by A. Henden
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