March 18, 2015: Dr. Paula Szkody, University of Washington, has requested our help in monitoring the cataclysmic variable GW Lib for upcoming Hubble Space Telescope observations, scheduled to be made during the window 2015 April 22-25 UT. Dr. Szkody also observed this object with HST in March 2011 and March 2010 (see AAVSO Alert Notices 433 and 417, respectively).
March 8, 2010: Further to Alert Notice 417, the AAVSO requests intensive monitoring observations of the cataclysmic variable GW Librae beginning immediately (2010 March 9.0 UT; JD 2455264.5) and continuing through 2010 March 12.5 (2455268.0). These observations are in support of the Hubble Space Telescope Cosmic Origins Spectrograph observations of GW Lib planned for 2010 March 11 UT. Space Telescope ground controllers will need to know that GW Lib is fainter than V=15 in order to proceed with the planned observations.
May 17, 2010: Dr. Michael Sitko (U. Cincinnati) requests observations of the young stellar object TW Hya in support of upcoming Hubble Space Telescope observations. TW Hya is believed to be a T Tauri star that varies between magnitudes 10.5 and 12.2. TW Hya will be observed with the HST STIS instrument as part of a larger program to study the properties of potentially planet-forming disks around young stars. The star will be observed in the ultraviolet to search for time-variability in the gas in the inner accretion disk.
April 29, 2014: Dr. Peter Garnavich (University of Notre Dame) and Dr. Paula Szkody (University of Washington) have requested the help of AAVSO observers in monitoring the cataclysmic variable SBS 1108+574 (= CSS 120422:111127+571239) in support of upcoming Hubble Space Telescope observations. The HST COS (Cosmic Origins Spectrograph) will be carrying out far-ultraviolet spectroscopy of this target on 2014 May 12-13 UT.
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: