August 24, 2017: Further to AAVSO Alert Notice 591, Dr. Boris Gaensicke (Warwick University) informs us that the first of three HST observations in his campaign on the pulsating white dwarf-containing cataclysmic variable GW Lib has been scheduled for
August 17, 2017: In AAVSO Alert Notice 593 we announced a campaign on the very long period VV Cep M2Iabe+B0/2Ve binary. The amplitude of the eclipse was wrongly given as slightly under a magnitude in the V band when it is actually around 0.1 mag. This means that the VV Cep eclipse is largely undetectable visually, and is not a good candidate for visual observations. CCD and DSLR photometry, however, are still encouraged.
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
August 7, 2017: Dr. Boris Gaensicke (Warwick University) has requested our help in monitoring the pulsating white dwarf-containing cataclysmic variable GW Lib in preparation for and support of K2 (Kepler's Second Light) and Hubble Space Telescope (HST) observations scheduled for August to November 2017 and August and September 2017, respectively.
K2 will be observing GW Lib non-stop 2017 Aug 23 20:00:00 to 2017 Nov 19 23:00:00 UTC.
August 7, 2017: AAVSO Young Stellar Object (YSO) Section leader Michael Poxon (Great Plumstead, Norfolk, UK) requests coverage of the YSO V1117 Her.
He writes: "The peculiar YSO V1117 Herculis has undergone a second, rapid fade and recovery only a few days after its recovery from another rapid fade. Observations, both visual and multiwavelength, are encouraged, since the behaviour of this star's historical fading episodes may indicate rapidly-changing evolution of the protoplanetary clumps in the circumstellar disc.
August 4, 2017: Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) has requested "visual, photometric, and spectroscopic observations of the symbiotic variable R Aqr in preparation for and in support of Chandra and HST observations currently scheduled for October 2017."
In order to help simplify answering the question "What should I observe tonight?", we have consolidated some of the places on the AAVSO website to look for information on urgently-needed observations. As of July 31, 2017, the three webpages:
July 28, 2017: The AAVSO Special Notice is being discontinued as of July 28, 2017. This notice - #430 - is the last Notice of the publication.
The type of information supplied in AAVSO Special Notices will now be supplied in the AAVSO Alert Notices and/or in the AAVSO online forums on Campaigns & Observation Reports, Time Sensitive Reports, and the other Variable Star Observing and Variable Star forums, as appropriate.
July 21, 2017: The following request for AAVSO assistance has been received from Denis Denisenko (Sternberg Astronomical Institute, Moscow State University) to help characterize "...the cataclysmic variable DDE 48 in Vulpecula. This CV belongs to the rare ER UMa subtype of dwarf novae, with only 6 other stars in VSX being classified as UGER. According to 2016-2017 observations by Nikolay Mishevskiy (MNIC) and Denis Denisenko (DDE), this variable is very active, with superoutbursts to magnitude V=15.4 occurring approximately once a month.
