Ultraviolet Spectrophotometry of Early-Type Stars.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet Spectrophotometry of Early-Type Stars. Stecher, Theodore P. Abstract The observations obtained by two rockets on stars in the summer sky are reported. The instrumentation used was similar to that previously reported by Stecher and Milligan (Astrophys. J. 136, 1, 1962). The spectral range has been increased to a short-wavelength limit of 1250 A. The spectral energy distribution of the stars is compared with a grid of model atmospheres recently computed by Mihalas and various other investigators. On the basis of the pre-flight calibration and with a surface gravity of log g =4, a temperature scale is provisionally assigned to the B stars on the basis of flux ratios between the visible and ultraviolet. This temperature scale gives around 25 0000K to the B0 stars and is in good agreement with recent ground based observational determinations in the A stars. An extension of the X-' law appears to give a reasonable approximation to interstellar extinction but is not sufficient at X2200. A single spectrum of Jupiter was obtained in the XX2000-3000 region. When the reflectivity is interpreted as Rayleigh and Raman scattering, an upper limit of 12 km atm of H2 is derived. This is under the assumption of all H2 and a ground reflectivity of zero. Any ground reflectivity or He in the atmosphere will reduce the amount of H2. The spectrum of the night airglow was obtained between X1250-3500. The total flux is less than 1200 Rayleighs of which 1000 Rayleighs is in the Herzberg O2 bands. Publication: The Astronomical Journal Pub Date: October 1964 DOI: 10.1086/109498 Bibcode: 1964AJ.....69S.558S full text sources ADS |