Issues on Finder Charts and Comparison Star Sequences (Abstract)

Volume 35 number 1 (2007)

W. M. Lowder

J. A. Mattei

Abstract

(Abstract only) Note from Elizabeth O. Waagen, AAVSO Headquarters: We do not have the abstract or the text of Wayne and Janet’s presentation. However, at the time of the AAVSO meeting in Sion, there were many issues related to finder charts and comparison star sequences for variable stars that needed resolution, including: • Current charts made by an organization: poor or incomplete comparison star sequences; confusing presentation of the variable star field • Charts made by different organizations: different sequences for the same variable star; different philosophies in choosing comparison star sequences, how organizations can work together to produce the best sequences for variable star observing and then adopt these sequences worldwide • The emerging surveys and catalogues offering magnitudes for potential comparison stars: which are appropriate for variable star work; which should be used and, not used • The rapidly-advancing CCD technology, which allows precise measurement of comparison star magnitudes: how to organize and coordinate this resource most efficiently to produce results to everyone’s benefit; what type of CCD observations are most appropriate for variable star comparison stars • The increasing numbers of variable stars being discovered: how to choose which stars to make charts for; how to improve methods of making charts, since current methods are too cumbersome for future (and current) needs Since the Sion meeting, much progress has been made and many papers have been published on these issues. In 2000 the International Chart Working Group was established to discuss and resolve these and other issues relating to charts and sequences. For an excellent discussion of the ICWG, see J. Toone’s article in JAAVSO 34, 1 (2005). A search of JAAVSO—and other organizations’ publications—will yield many articles discussing comparison stars, magnitudes, catalogues, chart-making software, etc. New initiatives are well underway in the AAVSO to digitize its entire database of comparison stars and to automate chart-making. The astonishing evolution of the internet is enabling the global adoption of sequences and the customization of charts: the long-held dream of everyone using the same sequences while having charts tailored to their personal needs—the ideal way to generate the most homogeneous data from multiple observers—is becoming a reality.