Alert Notice 592: V404 Cyg observations needed tonight for Chandra observations

August 11, 2017: Dr. Gregory Sivakoff (University of Alberta) and colleagues have requested AAVSO observers' assistance in observing the black hole X-ray transient LMXB V404 Cyg in support of Chandra observations taking place TONIGHT. The Chandra schedule is

2017 Aug 11 23:49:04.072  - 2017 Aug 12 13:42:14.730 UTC

Alert Notice 549: RX And Chandra observing campaign

September 1, 2016: Dr. Christian Knigge (University of Southampton) and colleagues have requested AAVSO coverage of the Z Cam dwarf nova RX And 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.

Alert Notice 523: Correction to AAVSO Alert Notice 522

July 1, 2015:  In AAVSO Alert Notice 522 on the upcoming observations of the black hole X-ray binary V404 Cyg by HST, the date of the detection by the Swift satellite was incorrectly given as 2015 June 16.77197 UT (Barthelmy et al., GCN Circular 17929). The correct date is 2015 June 15.77197 UT.

Our sincere apologies for this error!

Alert Notice 266: 0939-20 Supernova 1999gh in NGC 2986 AND 1058+45 AN Ursae Majoris to be observed with EUVE satellite

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AAVSO ALERT NOTICE 266 (December 6, 1999)

0939-20 SUPERNOVA 1999gh IN NGC 2986

Alert Notice 488: Observations of AA Tau requested to schedule XMM-Newton

August 1, 2013: Dr. Hans Moritz Guenther (Harvard-Smithsonian Center for Astrophysics) has requested nightly observations of the classical T Tauri star AA Tau in order to schedule x-ray observations with XMM-Newton that have been planned for between 2013 August 15 and September 15.

Special Notice #287: Request to observe X-ray transient Swift J1910.2-0546

June 28, 2012: The recently discovered gamma-ray source Swift J1910.2-0546 (Krimm et al., ATel #4139; Barthelmy et al., GCNC #13369; T. Ohshima., vsnet-alert 14674) is optically bright, reaching magnitude CR = 15.7 on 2012 June 14 (R. Pickard, BAAVSS, using the Faulkes Telescope South).  The object was also observed by A. Odasso, using the Sierra Stars Observatory Network (A.