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J. Bryan (McDonald Observatory)
In August 1885 a bright new star appeared near the center of the Andromeda Nebula, M31. Later called S Andromedae, it is now believed to have been a peculiar Type Ia supernova, and its remnant is an object of current interest. The star remained visible to the naked eye for days and was accessible in telescopes for months. Astronomers in Europe and America left an extensive but sometimes unclear record of the event that was observed almost entirely visually.
In 1885 E. E. Barnard was a student at Vanderbilt University and a comet discoverer. At the time, his interest in stars was apparently limited to their use as references to visually estimate the positions of comets. S And may have been his introduction to stars as objects of science. While he routinely communicated with journals, he never published his complete set of observations of S And. That is, other than to discuss in print apparent flickering of the star, there is no evidence that he made use of his numerous descriptions of its declining brightness.
Examination of his forgotten light estimates of S And gives insight into what Barnard knew of observational methods for variable stars in 1885. Comparison of his results to those of his contemporaries as well as to a modern version of the light curve reveal both his accuracy and the main problem that faced visual observers. S And was positioned nearly centrally on the nuclear bulge, and the bright background created trouble for magnitude estimation. His account is an interesting description of what it was like to observe this historic supernova. It also offers an interesting contrast with Barnard's remarkable light estimates of Iapetus during that satellite's series of eclipses in the shadows of the globe and ring system of Saturn in 1889.
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Bulletin of the American Astronomical Society, 35#5
© 2003. The American Astronomical Soceity.