Absolute fix measurements in the rocket ultraviolet.
Abstract
Summary. A two-channel spectrometer was calibrated in the wavelength region i20( 3400 A and flown on an Aerobee rocket to observe the stars oc Lyr, `iUMa, and Oph. Standard tungsten lamps provided the absolute calibration down to 2250 A and a photodiode calibrated by the National Bureau of Standards was the reference at shorter wavelengths. The molecular branching-ratio technique of relative calibration using the gases CO, NO, and N2 was a check on the absolute calibration. The flux from UMa agrees with the prediction of a hydrogen line blanketed model atmosphere within 10% between 1700 and 3400 A and within 4% over most of this wavelength region. Key words: absolute calibration - ultraviolet spectrophotometry -?I UMa
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- January 1974
- Bibcode:
- 1974A&A....30..127B