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
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.
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!
Correction: In the text below, the date of the detection by the Swift satellite was incorrectly given as 2015 June 16.77197 UT. The correct date is 2015 June 15.77197 UT.
Our sincere apologies for this error!
July 1, 2015:
THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET: aavso@aavso.org
Tel. 617-354-0484 FAX 617-354-0665
AAVSO ALERT NOTICE 254 (February 22, 1999)
MINOR OUTBURST OF 0324+43 GK PERSEI
THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET: aavso@aavso.org
Tel. 617-354-0484 Fax 617-354-0665
AAVSO ALERT NOTICE 266 (December 6, 1999)
0939-20 SUPERNOVA 1999gh IN NGC 2986
THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
INTERNET: aavso@aavso.org
Tel. 617-354-0484 Fax 617-354-0665
AAVSO ALERT NOTICE 271 (February 10, 2000)
1749-19 N? SGR 00 - POSSIBLE NOVA IN SAGITTARIUS
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.
June 20, 2013: Dr. Andrea Dupree (Harvard-Smithsonian Center for Astrophysics) has requested AAVSO monitoring of the symbiotic variable AG Draconis from now through at least September 2013 for correlation with upcoming Chandra x-ray and HST ultraviolet observations.
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.
