WZ Sge star

Alert Notice 450: Request for observations of SDSS J080434.20+510349.2‭ ‬in support of HST observations

October 25‭, ‬2011: Dr‭. ‬Paula Szkody‭ (‬University of Washington‭) ‬has requested the help‭ ‬of AAVSO observers in monitoring the WZ Sge-type cataclysmic‭ ‬variable SDSS J080434.20+510349.2 (SDSS0804+51)‭ ‬in support of Hubble Space Telescope ultraviolet‭ ‬spectroscopic observations scheduled for 20:52:40‭ - ‬23:32:35‭ ‬2011‭ ‬November 3‭ ‬UT‭ (‬the night of Wednesday‭, ‬November 2/3‭)‬ ‭(‬JD 2455869.36991-‭.‬48096‭). ‬Nightly observations are requested‭ ‬beginning immediately and continuing through November 30‭.

Special Notice 255: Cataclysmic Variable in Draco = PNV J18422792+4837425

September 14, 2011: IAU CBAT Central Bureau Electronic Telegram 2818 (Daniel W. E. Green, ed.) announces the discovery by Hideo Nishimura, Miyawaki, Kakegawa, Shizuoka-ken, Japan, of a cataclysmic variable in Draco on 2011 Sept. 5.529 UT at magnitude 11.8 (reported by S. Nakano, Sumoto, Japan). The variable was designated PNV J18422792+4837425 when posted on the Central Bureau's TOCP webpage.

Special Notice #245: Outburst of SV Ari

August 2, 2011:  SV Ari, a suspected WZ Sge star, has gone into outburst.  Rod Stubbings posted a 15.0 magnitude estimate on 110802.788 that has been confirmed by Gianluca Masi.  Gary Poyner says:

"Discovered by M & G Wolf on Heidelberg plates taken in November 1905 at mag 12.0p.  Kimpel & Jansch reported a possible sighting in September 1943, but this was not confirmed.  Nothing has been seen since."

Special Notice #239: Dwarf Nova in Pegasus (PNV J21095047+1348396)

May 31, 2011: IAU Central Bureau for Astronomical Telegrams Electronic Telegram CBET 2731 (Daniel W. E. Green, ed.) announces the discovery by K. Itagaki, Yamagata, Japan, of a dwarf nova in Pegasus (reported by H. Yamaoka, Kyushu University, Japan) on 2011 May 24.672 UT at unfiltered CCD magnitude ~11.5. Spectroscopy by Akira Arai, Koyama Astronomical Observatory, Kyoto Sangyo University, Japan, on 2011 May 25.67 UT, and by D. D. Balam, Dominion Astrophysical Observatory, National Research Council of Canada, M. L.

Alert Notice 434: Outburst of NSV 1436

March 30, 2011: The cataclysmic variable NSV 1436 has been discovered in outburst.  This is the first bright outburst of this star observed since 1948, and followup observations are strongly encouraged.  Little is known about the nature of NSV 1436, and observations may help shed light on whether the star is an infrequently outbursting normal dwarf nova, a WZ Sge star, or recurrent nova.

Special Notice #233: Bright outburst of the cataclysmic variable SDSS J133941.11+484727.5

February 7, 2011: The star SDSS J133941.11+484727.5 has been reported in outburst by Jeremy Shears (Bunbury, UK).  Shears reports this star at magnitude 10.4 on 2011 February 7.919 (JD 2455600.419).  This is approximately 7 magnitudes above quiescence, which suggests a superoutburst of an SU UMa star or a WZ Sge-like outburst.  Gary Poyner (Birmingham, UK) confirms this outburst, estimating the star at 10.5 on February 7.959 (2455600.459).

Special Notice #225: A new UGWZ candidate in Pisces

December 1, 2010: A bright transient in Pisces was discovered by K. Itagaki at an unfiltered magnitude of 12.3 on 2010 November 30.50663 UT (JD 2455531.00663; reported by H. Yamaoka in vsnet-outburst 11854). The object was confirmed at V=12.1 by A. Oksanen (Muurame, Finland) shortly afterward (vsnet-outburst 11855), and I. Miller (Swansea, Wales, UK) reported the presence of superhumps with period 0.0571 day (reported by T. Kato, vsnet-outburst 11859). As noted by Yamaoka and by R.

Special Notice #224: Possible outburst of SDSS_J160501.35+203056.9

November 21, 2010: Hitoshki Yamaoka reports in VSNET-ALERT 12411 of the observation by Itagaki of SDSS J160501.35+203056.9, a suspected cataclysmic variable.  In quiescence, it is about mag20.  Itagaki-san's observation on 2010-11-21 was 12.0 unfiltered.  If confirmed, this would yield an outburst magnitude of 8 magnitudes, and would place it in the realm of the WZ Sge class, rare stars in the cataclysmic category that have superoutburst cycles of decades.  The spectra in Szkody, et al.