Spectrophotometric observations of geocoronal and interplanetary helium resonance radiation.
Abstract
Results are reported for spectrophotometric observations of geocoronal and interplanetary helium radiation by means of a rocketborne helium resonance cell and a photometer with tin filters at the front and exit of the cell. During a daytime mission the geocoronal and interplanetary helium radiation was observed from heights of 400 to 720 km at 22 positions in a region 20 deg away from the sun. It is found that the observed intensity at heights above 600 km was primarily of interplanetary origin and that the observed geocoronal and interplanetary components varied in the ranges from 60 to 100 R and from 7 to 10 R, respectively. The results indicate that only resonance radiation from neutral helium could be detected in the wavelength band from 500 to 800 A at heights above 400 km and that the velocity components of the interplanetary helium were less than 30 km/s along the line of sight passing the sun at a closest distance of 0.3 AU.
- Publication:
-
Space Research XVIII
- Pub Date:
- 1978
- Bibcode:
- 1978spre.conf..385W
- Keywords:
-
- Background Radiation;
- Geocoronal Emissions;
- Helium;
- Interplanetary Medium;
- Interstellar Radiation;
- Spectrophotometry;
- Optical Resonance;
- Rocket-Borne Instruments;
- Stellar Winds;
- Ultraviolet Spectra;
- Astrophysics;
- Geocorona:Helium;
- Helium:Interplanetary Space