THE ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 96:605-626, 1995 February

    FAR-ULTRAVIOLET STELLAR PHOTOMETRY: FIELDS IN SAGITTARIUS AND SCORPIUS

                               EDWARD G. SCHMIDT
        Division of Astronomical Sciences, National Science Foundation,
     4201 Wilson Boulevard, Arlington, VA 22230; eschmidt@unlinfo.unl.edu

                                      AND

                             GEORGE R. CARRUTHERS
 E.O. Hulburt Center for Space Research, Code 7609, Naval Research Laboratory,
                           Washington, DC 20375-5320


                                   ABSTRACT

        Far-ultraviolet photometry for 741 objects in a field in
     Sagittarius centered near M8 and 541 objects in a field centered near
     zeta 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
     lambda_eff = 1375 A and lambda_eff = 1781 A. 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-1, OAO 2, and ANS
     satellites and the S201 (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.
 
     Subject headings: stars: early-type -- surveys -- techniques:
                       photometric -- ultraviolet: stars