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Intensity measurements of chromospheric fine structures in Lyman-α

✍ Scribed by William A. Sloan

Publisher
Springer
Year
1968
Tongue
English
Weight
440 KB
Volume
5
Category
Article
ISSN
0038-0938

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✦ Synopsis

The intensity of the sun was measured in the Lyman-a emission line with 2.5 arc-seconds of resolution. The experiment was flown in an Aerobee-150 rocket on April 28, 1966. It contained a Cassegrain telescope with a pinhole aperture placed at the focus followed by a gas-gain ionization chamber whose spectral response was 1050 A to 1350/~.

An isophote map 1.5 by 3 arc-minutes in size made from a composite of 90 linear scans shows an enhanced region and adjacent to it a prominent dark lane 20 arc-seconds wide. The measured intensity ratio of these two regions is nine. Bright features between 6 and 20 arc-seconds in size showed typical peak intensities of 20~ greater than the surrounding chromosphere. The smallest features observed were 2.5 arc-seconds in size. A direct measurement of the absolute intensity at 1216/~ gave a value of 5.9 • 104 erg cm 2 s-1 sterad 1 in the quiet chromosphere.

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