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cataclysmic variable

Special Notice #66: HS 2331+3905 Named V455 And

September 12, 2007: According to IAU Circular 8868 (Daniel E. W. Green, editor), N. N. Samus, Institute of Astronomy, Moscow, reports that the dwarf nova cataclysmic variable 2328+38 HS 2331+3905 is now V455 And, and HS 2331+3905 has been assigned the official name V455 And. The AAVSO validation file has been changed to reflect this new name. Please use V455 AND when reporting observations.

V455 AND is located at RA 23:34:01.55, Dec +39:21:42.9 (J2000)

Special Notice #76: Support for HST observations of SDSS074545, update

October 29, 2007: We have been informed by Paula Szkody that HST observations of SDSS074545 have been tentatively scheduled for the night of 2007 October 31/Nov 01 UT (approximate JD 2454405.56). Observations are pending ground-based confirmation that this cataclysmic variable is not in outburst and is thus faint enough to safely observe with HST. This decision will be made on the afternoon of Wednesday, 2007 October 31 UT, and so observations are critically needed during the night of 2007 October 30/31 UT (JD 2454404.5).

Special Notice #79: Update of Alert Notice 361: HST Observations of SDSS091908

November 12, 2007: This is an update to the Request for Observations given in Alert Notice 361, on upcoming Hubble Space Telescope observations of SDSS091908, a cataclysmic variable with a pulsating white dwarf primary.

Alert Notice 586: Status of 20 cataclysmic variables needed for WHT campaign

July 7, 2017: Roque Ruiz-Carmona (Ph.D. candidate, Institute of Mathematics, Astrophysics and Particle Physics, Radboud University Nijmegen, The Netherlands) has requested AAVSO assistance in determining the status of 20 eclipsing cataclysmic variables (CVs) in order to select one system in outburst for observation with the William Herschel Telescope (WHT) at La Palma, to detect and study spiral density waves in the system. The WHT observations will begin on 2017 July 11 UT.

Special Notice #89: Rare Outburst of 0103+59 HT Cas

January 10, 2008

Coordinates: RA 01:10:12.98 Dec. +60:04:35.9 (2000.0)

AAVSO observer Glenn Chaple, Townsend, MA, reports that the UGSS+EA type dwarf nova HT Cas is in outburst for the first time since February 2002, with his visual observation of 13.6 on January 10.0076 UT. Makoto Uemura and colleagues at Hiroshima University (vsnet-alert 9807) confirmed the outburst with an observation of 14.02V on January 10.5278 UT. This outburst looks to be a normal, brief outburst, probably lasting only 2-3 days.

Special Notice #91: BZ UMa Monitoring for Polarization Measurements

January 14, 2008: Photometric and visual observations of the dwarf novae BZ UMa are


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