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dwarf nova

Special Notice #211: Outburst of EX Hya

May 22, 2010: Rod Stubbings has reported that the infrequently outbursting dwarf nova EX Hydrae is in outburst. Stubbings reported the star at a visual magnitude of 9.4 on 2010 May 22.667 (JD 2455339.167) and it remained at 9.4 through May 22.721 (2455339.221). Both visual and instrumental observations of EX Hya are urgently requested. CCD observers, please obtain time-series photometry if at all possible. Please follow this outburst through its completion; EX Hya is known to have short outbursts, so this outburst may be very brief.
 

Special Notice #206: Request for photometry of the dwarf nova SS Cygni

April 21, 2010: Further to AAVSO Special Notice #204 (2010 April 15), we are requesting additional observations of the bright dwarf nova SS Cygni currently in outburst. SS Cyg is currently beginning a dwarf nova outburst, and observations of this star made with the EVLA have detected the source at radio wavelengths. Observations of SS Cyg have been scheduled with the VLBA on 2010 April 22 and April 23.

Special Notice #382: SDSS J100658.40+233724.4 observations crucial now

March 17, 2014: HST/COS is scheduled to observe the the U Gem-type dwarf nova
SDSS J100658.40+233724.4 this Thursday. Observations are scheduled for:

SDSS J100658.40+233724.4 2014 March 20 05:35:00 through 14:17:27 UT

Special Notice #381: HST/COS observations of SDSS J100658.40+233724.4

March 5, 2014: HST/COS are being scheduled for the U Gem-type dwarf nova SDSS J100658.40+233724.4, the 40th and final target of the major CV observing campaign organized in 2012 by Drs. Boris Gaensicke, Joseph Patterson, Arne Henden, and 13 other astronomers (see AAVSO Alert Notice 471 and note below). A precise time will be announced later, but the scheduled HST observing window is:

Special Notice #377: Reported outburst of the WZ Sge star AL Comae

December 6, 2013: Observer Carlo Gualdoni reports via the cvnet-outburst mailing list that the WZ Sge-type dwarf nova AL Comae is in outburst, with a magnitude of V=12.74 on 2013 December 6.185 (JD 2456633.1185).  Gary Poyner notes on the BAAVSS mailing list that this is the first observed outburst of AL Com since October 2007.  Both visual observations and CCD time series are encouraged.

Special Notice #376: HST observations of U Gem scheduled for December 6

December 2, 2013: Further to AAVSO Special Notice #318 (M. Templeton) and AAVSO Alert Notice 475 (E. Waagen), Dr. Michael Shara (American Museum of Natural History) informs us that HST/COS observations of the dwarf nova U Gem have been scheduled for 2013 December 6 UT (one day earlier than originally indicated in the December 2 posting to the AAVSO forums). The observations will take place:

Alert Notice 278: 1017-49 V383 Velorum (NSV 4834) = new dwarf nova

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 278 (November 20, 2000)

1017-49  V383 VELORUM (NSV 4834) = NEW DWARF NOVA

Alert Notice 290: Supernova 2001el in NGC 1448 (Horologium) AND Request to monitor cataclysmic variables for XMM-Newton observations

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 290 (September 20, 2001)

0341-44B  SUPERNOVA 2001el IN NGC 1448 (HOROLOGIUM)

Alert Notice 295: 1753-30B Nova Sagittarii 2002 AND 0006-12 WW Cet request to monitor for RXTE observations

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 295 (April 16, 2002)

1753-30B  NOVA SAGITTARII 2002

Alert Notice 139: Nova Herculis 1991 AND Outburst of 2325+43 DX Andromedae

THE AMERICAN ASSOCIATION OF VARIABLE STAR OBSERVERS
25 Birch Street, Cambridge, MA 02138 USA
BITNET: aavso@cfa8 SPAN: nssdca::cfa8::aavso
Tel. 617-354-0484 FAX 617-354-0665

                        AAVSO ALERT NOTICE 139 (March 29, 1991)

NOVA HERCULIS 1991

This bright nova is fading rather fast as indicated by the following observations:

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