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APASS DR1 happening soon!

Posted by HQA on August 21, 2010 - 7:27am

We've been busy during the monsoon shutdown of the APASS system, processing images and preparing for the first formal release of photometry from this AAVSO system.

The AAVSO Photometric All-Sky System (APASS) was commissioned in December, 2009, and has been taking images at Dark Ridge Observatory (Tom Smith, Weed, New Mexico) ever since.  New Mexico has experienced a particularly strong el Nino weather pattern, and that combined with the usual startup hardware and software problems, means that we are slightly behind our predicted observing pace.  Nonetheless, we have acquired data on over 50 nights, and are preparing a formal Data Release (DR1).  This should happen with a week or two, so keep watching the home page!


We're hoping to give you access through both a visual display tool (Seqplot) and a query form for larger requests.  Currently, the astrometry for APASS is better than one arcsec, especially in sparse fields, and the photometry is about 0.03-0.05 mag accuracy, depending on the number of nights of observation and their quality.  DR1 will include all objects with at least two nights of observation; the final catalog will have a minimum of four photometric observations per object.

The original APASS system will be packed and shipped to CTIO at the end of September, where it will be installed in one of the PROMPT domes (Dan Reichart, UNC, has graciously granted us space there).  We will be purchasing a new system to be installed at DRO that will complete the northern sky at the same time as the original system covers the southern sky.  The next data release, expected at the end of the year, will therefore have both northern and southern fields represented.

This has been a fun project, impossible to have taken place without the funding from the Robert Martin Ayers Sciences Fund, as well as the volunteer effort from many people.  At the same time, it is an extremely important project for the astronomy community as a whole, and we are already getting enthusiastic responses from many researchers.  Keep tuned for more!

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