Confessions of a Variable Star Observer
Presenter(s): Roy Axelsen
Affiliation(s): Astronomical Association of Queensland; Variable Stars South; American Association of Variable Star Observers
Session details: Sunday, 2026-04-05 03:30:00
Abstract
This is a lighthearted trip across about 20 years of amateur astronomical activities, mostly variable star observing. It starts with visual estimates of the magnitudes of variable stars, moves on to photoelectric photometry (PEP), abandons laborious PEP for DSLR photometry and ends with a monochromatic CMOS astronomical camera (actually, two of them one at a time), a filter wheel and scientific filters. Along the way there are serious looks at light curves that reveal the true natures of stars and the ways in which they can be analysed to yield new publishable data. There are various instruments starting with a pair of 7×50 binoculars, a 10” f/5 push-to Dobsonian, a brief love affair with an 18” f/5 truss-tube Dobsonian fitted after a while with an Argo Navis telescope computer, 80mm and 120mm f/7.5 ED refractors on equatorial mounts which gave me some of my most fruitful data, and finally a 200mm f/10 Schmidt-Cassegrain instrument on (of all things) an equatorial wedge. As the title says there are confessions, which are about what perhaps should and should not have been done, but there are no regrets.
Biography
Roy Axelsen has observed variable stars for a little over 20 years. He has submitted data from visual observations, photoelectric photometry, DSLR photometry and photometry with a monochromatic CMOS astronomical camera to the international database of the American Association of Variable Star Observers. More recently, he has observed southern eclipsing binary stars with short periods for Variable Stars South. He has several publications, mostly on delta Scuti stars, for which he was awarded the Page Medal of the Astronomical Society of Australia in 2016. He has been a co-author in a couple of papers on eclipsing binary stars. He has been an active member of the Astronomical Association of Queensland for over 20 years, and at the time of writing was General Secretary.