AAVSO: American Association of Variable Star Observers

Techniques of Photometry and Astrometry with APASS, Gaia, and Pan-STARRs Results (Abstract)

Volume 45 number 2 (2017)

Wayne Green
7131 Oriole Lane, Longmont, CO 80503; dxwayne@gmail.com

Abstract

(Abstract only) The databases with the APASS DR9, Gaia DR1, and the Pan-STARRs 3π DR1 data releases are publicly available for use. There is a bit of data-mining involved to download and manage these reference stars. This paper discusses the use of these databases to acquire accurate photometric references as well as techniques for improving results. Images are prepared in the usual way: zero, dark, flat-fields, and WCS solutions with Astrometry.net. Images are then processed with Sextractor to produce an ASCII table of identifying photometric features. The database manages photometics catalogs and images converted to ASCII tables. Scripts convert the files into SQL and assimilate them into database tables. Using SQL techniques, each image star is merged with reference data to produce publishable results. The VYSOS has over 13,000 images of the ONC5 field to process with roughly 100 total fields in the campaign. This paper provides the overview for this daunting task.