Department of Physics and Astronomy: Publications and Other Research
Date of this Version
February 1995
Abstract
Far-ultraviolet photometry for 741 objects in a field in Sagittarius centered near M8 and 54 1 objects in a field centered near ζ Scorpii is presented. These data were extracted from electrographic images obtained with two cameras during a shuttle flight in 1991 April/May. The cameras provided band passes with λeff= 1375 Å and λeff= 1781 Å. Synthetic colors show that these bands are sensitive to effective temperature for hot stars. Our measurements were placed on a quantitative far-ultraviolet magnitude scale by convolving the spectra of stars observed by IUE with our cameras' spectral response functions. Fifty-eight percent of the ultraviolet objects were identified with visible stars using the SIMBAD database while another 40% of the objects are blends of early type stars too close together to separate with our resolution. Our photometry is compared with that from the TD-I, OAO 2, and ANS satellites and the S20 1 (Apollo 16) far-ultraviolet camera and found to agree at the level of a few tenths of a magnitude. Unlike previous studies, almost half of the identified visual counterparts to the ultraviolet objects are early B stars. A plot of distance modulus against ultraviolet color excess reveals a significant population of stars with strong ultraviolet excesses.
Comments
Published inThe Astrophysical Journal Supplement Series 96, pp.605-626 (February 1995). Published by the University of Chicago Press; copyright © 1995 American Astronomical Society; reproduced by permission of the AAS.http://www.noao.edu/apjsup/apjsup.html