The role of the amateur in astronomy is changing, with new opportunities for real scientific contributions. The American Association of Variable Star Observers (AAVSO) and its members have been on the forefront of this trend for decades. The kind letter of thanks, posted today on the AAVSO discussion groups, exemplifies the spirit of collaboration between amateur and professional that is becoming an increasingly important element to astronomical research. Moreover, I believe this trend helps to build grass-roots support for funding in astronomy – a profoundly interesting scientific endeavor whose practical applications are harder to define. My advice to anyone out there young or old interested in learning about astronomy or computers (or both!) – join in! Become a part of the process. Don’t just learn about science. Do science!
Date: Sun, 20 Sep 2009 16:00:19 -0400
From: Ed Smith
Subject: AAVSO! THANK YOU for support of the Hubble’s Cosmic Origins SpectrographDear Dr. Templeton and members of the AAVSO,
I write on behalf of the Cosmic Origins Spectrograph (COS) teams at the Space Telescope Science Institute and the University of Colorado. We send our gratitude for your support of the recent successfully completed Hubble Space Telescope (HST) observations with COS of the Symbiotic Star, AG Draconis. Particular recognition must be given the dedication and many nights of observations made by Gordon Myers.
The observing programs targeting AG Dra were part of the process of verification of the instrument’s on-orbit capabilities.
The COS detectors are subject to permanent damage if exposed to a light source that is “too” bright. Various other requirements for several of our on-orbit checks led to the curious choice of AG Dra as the desired target. As you well know this object has outbursts of as much as 5 magnitudes in the U band, brightening on short time scales and with intermittent repeatability!
Without your frequent observations and rapid analysis providing assurance that the object remained quiescent in the weeks and then days leading up to the HST COS observations, we would not have risked scheduling these observations. Indeed, we remained prepared to halt the observations in the final days and hours if you had reported a sudden brightening.
Thanks to your support, successful measurements made using AG Dra are providing important characterizations of how the instrument is operating on-board Hubble. The “COS/NUV Spectral and Thermal Stability” experiment held the shutter open nearly continuously for ~8 hours with continuous readout of the spectrum. We are measuring the position of the spectra on the detector to characterize the amount and variation of drifts in that position. We expect to relate the changes to such things as the thermally induced expansion and contraction of the Hubble telescope and COS mechanisms as they undergo the day and then night portions of the spacecraft’s orbit.
Characterizations such as these not only verify the proper functioning of the instrument, but enable finely tuned interpretations of things such as temporal variation in the scientific measurements of future programs.
The other two COS programs that targeted AG Dra are titled “COS NUV and COS FUV External Spectroscopic Performance -Part 2″. These programs characterize the spatial profile of spectral lines produced by each of the gratings used with the FUV and the NUV detectors.
The results of these programs will be reported in technical documents available via the web-site at STSCI in the coming months. Your valued contribution will be acknowledged in each relevant publication.
(My emphasis).Thank you so much for your dedication and hard work in support of a new era of NUV/FUV spectroscopy from the Hubble Telescope with the Cosmic Origins Spectrograph.
-Ed Smith
Research and Instrument Scientist
Space Telescope Science Institute
3700 San Martin Blvd.
Baltimore, MD. 21218
