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AAVSO Special Notice

History of AAVSO Alert Notices and AAVSO Special Notices

Notifying observers and researchers of discoveries and requests for AAVSO observing assistance

Prior to the inception of the AAVSO Alert Notice in 1974, observers were alerted to a discovery or the need for observations of an object via a post card from AAVSO HQ or, if extremely urgent, a phone call from the Director or his/her assistant.

The AAVSO Alert Notice

Special Notice #429: V694 Mon (MWC 560) spectroscopy requested

May 2, 2017: Further to AAVSO Alert Notice 538, the campaign from 2016 on V694 Mon (MWC 560) has been continued, but with different requirements. Photometry is no longer specifically requested on a regular basis (although ongoing observations that do not interfere with other obligations are welcome). Spectroscopy on a cadence of a week or two is requested to monitor changes in the disk outflow. V694 Mon is presently nearing opposition, but the request for spectroscopy continues until further notice.

Special Notice #428: YZ Cnc Chandra observing window delayed

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.

Special Notice #427: Please continue YZ Cnc coverage for Chandra TOO observations

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.

Special Notice #426: Blazar CTA 102 (4C 11.69) in very bright outburst

December 1, 2016: The blazar CTA 102 (4C 11.69) has been in an active state in gamma-ray and optical wavelengths since 2015. During 2016, it has had numerous flaring episodes, particularly since late October. It is presently in an unprecedentedly bright optical state, and showing substantially increased emission in gamma-ray and near-infrared wavelengths.

Special Notice #425: FO Aqr XMM-Newton observations scheduled

November 9, 2016: Further to AAVSO Alert Notice 545, time series observations of the intermediate polar cataclysmic variable FO Aqr are requested to provide simultaneous coverage of XMM-Newton observations scheduled for 2016 November 13 19:43 UTC to November 14 8:13 UTC.

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