Ultraviolet Spectrophotometer for Satellite Astronomy.

Abstract

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Ultraviolet Spectrophotometer for Satellite Astronomy. Hallam, Kenneth ; Magnus, John Abstract An astronomical spectrophotometer is described which was designed for use on 050-B, the second U. S. Orbiting Solar Observatory. The spectrophotometer is intended to analyze the ultraviolet emission from stars and nebulae. The entrance slit of the spectrophotometer defines the field at the primary focus of a 6-in. Gregorian reflecting telescope. The secondary serves as the collimator for a rotating 1200 lines/mm plane reflection grating. Diffracted light from the grating is collected by an off-axis parabaloid and focused through the exit slit ot the photomultiplier. The signal from the photomultiplier is pulse-counted and fed into the magnetic tape storage of the spacecraft. The instrument utilizes the spin of the gyroscopically stabilized satellite to sweep the 10 X 0.40 field over the celestial sphere. Slow precession of the spin axis allows eventual converage of the whole sky. Ten adjacent wavelength bands of 180A width between 1500A and 3300A are defined by succesive steps of jLhe grating. An input flux of 4X 10-~ erg/sec Cm2 A or over results in a statistical error in the output of 2%, while a flux 8 x 10-" erg/sec Cm2 A may be determined within 10% mean error. This sensitivity will permit useful observations of stars 5 stellar magnitudes fainter then the brightest ones. Details of the optical system and special requirements imposed upon it by characteristics of its special environment are reviewed. Publication: The Astronomical Journal Pub Date: 1964 DOI: 10.1086/109395 Bibcode: 1964AJ.....69Q.543H full text sources ADS |