Intrinsic Variability of Eclipsing Variable beta Lyrae Measured With a Digital SLR Camera (Abstract)

Volume 38 number 1 (2010)

Donald F. Collins

Abstract

(Abstract only) Continued observations of β Lyr with a DSLR camera with a standard-issue zoom lens (focal length: 55 mm; f/5.6) on an unguided tripod clearly show the well-known eclipse light curve where the magnitude drops about 0.6 magnitude every 12.94 days. After the eclipse light curve is subtracted the data show a definite intrinsic variability with a cycle time ~280 days. These observations were begun in June 2008 and are continuing through the present. The portability of the equipment and quick observation time should encourage many observers to make these observations while reserving telescopes for observing fainter objects. It is desired to obtain several years of similar observations of β Lyr in order to understand the cause of the intrinsic variability. The wide field of view using photographic lenses as opposed to telescopes, while advantageous for bright stars, presents special problems in obtaining suitable flat fields and measuring for atmospheric extinction. The use of electroluminescent film as a source for flat fields will be evaluated. Problems correcting for atmospheric extinction will also be discussed.