The solar ultraviolet spectrum from a V-2 rocket.
Abstract
As a portion of the upper atmospheric research program in progress at this laboratory, the solar ultraviolet spectrum was photographed from a V-2 rocket. Successful spectrograms were obtained at 35 altitudes ranging from I to 88 km. A vacuum spectrograph was designed for the purpose and employed a grating of 40 cm radius and 15,000 lines to the inch. A lithium fluoride sphere of 2 mm diameter was used in place of the slit and the record was made on a ~5-foot length of 35 mm film. The resolution was 3 A or better. At 34 km ozone absorption obscured the spectrum between 2650 A and 2260 A, but a definite spectrum was recorded from 2260 to 2100 A. The spectrum at 55 km was photographed through the entire region hitherto obscured by the Hartley band of ozone. Among prominent features of the spectrum were the strong absorptions at 2800 and 2852 A due to IJgii and Mgi, respectively. The preliminary intensity distribution at 55 km, calculated from the densitometer trace with the aid of a carbon arc as standard source, showed no obvious dip corwsponding to the Hartley band of ozone. It, therefore, appeared that less than one or two per cent of the total ozone lay above this altitude. The envelope of the preliminary intensity distribution fell progressively below the 6ooo0K black body curve to shorter wave lengths, and at 2200 A the departure was at least a factor of ten. U. S. Naval Research Laboratory, Washington, D. C.
- Publication:
-
The Astronomical Journal
- Pub Date:
- 1947
- DOI:
- 10.1086/106028
- Bibcode:
- 1947AJ.....52R.158T