COS

Alert Notice 604: CI Aql observations must be reported by 14:45 UT 2017 November 1

October 31, 2017: Further to AAVSO Alert Notice 603, your positive observations of CI Aql, which will be used to determine whether the HST observation of CI Aql will take place, must be submitted to the AAVSO International Database by 14:45 UT (10:45 am EDT) on Wednesday, 2017 November 1. Without these positive ground-based observations reported by this time (and showing CI Aql not in outburst), the HST observation will not take place.

Alert Notice 567: IM Nor monitoring requested for HST COS observations

February 10, 2017: Dr. Ed Sion (Villanova University) and colleagues have requested AAVSO observers' assistance in monitoring the symbiotic-type recurrent nova IM Nor in support of observations with the Hubble Space Telescope Cosmic Origins Spectrograph scheduled for 2017 February 13 - 17 UT.

These observations are part of a study on short orbital period recurrent novae as Supernovae Type Ia progenitors.

Alert Notice 558: CI Aql monitoring needed to support HST observations

October 19, 2016: Dr. Edward Sion (Villanova University) has requested AAVSO observers' assistance in monitoring the recurrent nova CI Aql in support of observations with the Hubble Space Telescope Cosmic Origins Spectrograph scheduled for October 31 - November 2, 2016, and November 3 - November 5, 2016. These observations are part of a study on short orbital period recurrent novae as Supernovae Type Ia progenitors.

Special Notice #385: SBS 1108+574 HST/COS observations crucial NOW

May 13, 2014: The HST/COS observations of the cataclysmic variable SBS 1108+574 described in AAVSO Alert Notice 501 and Special Notice #384 are scheduled for 2014 May 16 06:19:04 - 15:16:56 UT.

Your observations TONIGHT AND PARTICULARLY TOMORROW NIGHT ARE CRUCIAL!

Special Notice #384: SBS 1108+574 HST/COS obs next week

May 9, 2014: The HST/COS observations of the cataclysmic variable SBS 1108+574 described in AAVSO Alert Notice 501 have been pushed back a few days. The new exact time of the observations is:

                 SBS 1108+574      2014 May 16 06:19:04 - 15:16:56 UT

Alert Notice 501: Monitoring requested for HST/COS observations of SBS 1108+574

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.

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

The scheduling team will likely make their final decision early WEDNESDAY (March 19), so your observations are essential tonight and tomorrow night.

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:

SDSS J100658.40+233724.4  2014 Mar. 20 or 21 UT (to be determined)

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: