A spectroscopic determination of the pressure in the calcium chromosphere
Subtitle: On the physical interpretation of spectroheliograms; On the thermal excitation of atoms in the reversing layer of the sun.
By: By Albrecht Unsöld ...
Series: Contributions from the Mount Wilson Observatory.; nos. 377, 378, 379
Published: 1929
Place of publication: [Chicago
Language: eng
Number of pages: 18
Subjects: Spectrum, Solar.; Calcium.; Sun.
Notes: Cover-title.
At head of title: Carnegie Institution of Washington.
"Reprinted from the Astrophysical Journal, vol. LXIX, 1929."