+--------------------------------------------------------+ | STScI Analysis Newsletter (STAN) | Cosmic Origins Spectrograph (COS) | May 2010 +--------------------------------------------------------+ Visit the "New in the Last 45 Days" section of the COS website at http://www.stsci.edu/hst/cos for new information about COS. This and previous issues of the STAN can be found at http://www.stsci.edu/hst/cos/documents/newsletters. Contents: -Evolution of the COS Spectroscopic Throughputs over Time -Changes in the COS NUV Channel Dark Rate +--------------------------------------------------------+ Evolution of COS Spectroscopic Throughputs over Time The throughput of a number of COS spectroscopic modes has been declining more rapidly than had been anticipated at the time of launch. Here we detail our current understanding of these changes. COS NUV MAMA Dark Count Rate After COS installation during SM4, the COS NUV MAMA dark count rate had been initially found to be substantially lower than pre-launch estimates. However, since that time, the observed dark rate has been increasing +----------------------------------------------------------+ | Need help? http://www.stsci.edu/hst/cos/help.html +----------------------------------------------------------+ | To subscribe or unsubscribe to the STAN, send a message | to majordomo@stsci.edu with a blank subject line and | the following in the body: [un]subscribe cos_news +----------------------------------------------------------+ | The Space Telescope Science Institute is operated by the | Association of Universities for Research in Astronomy, | Inc., under NASA contract NAS5-26555. +----------------------------------------------------------+
