Consequences of a chromospheric temperature gradient on the width of H Alpha in late-type giants

Author: Zarro, D. M.
Published: Feb 1, 1984.
Physical Description: 1 electronic document

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Summary

An analytic expression for the integrated H alpha optical depth profile is derived for a one dimensional slab geometry model chromosphere, with electron temperature increasing as a power law with height. The formula predicts H alpha opacity and profile width to be sensitive functions of the thermal gradient. Application of the model to observation reveals that broad H alpha absorption widths in G and K giant stars are consistent with a mean H alpha chromospheric optical depth of 50, while narrower widths in M stars indicate slightly lower opacities. It is proposed that differences in H alpha width between late-type giants of similar spectral type may be due, in part, to differences in their chromospheric thermal gradient, and associated H alpha opacity.

Other Subject(s)

ASTROPHYSICS

Collection

NASA Technical Reports Server (NTRS) Collection.

Note

Document ID: 19840011192.
Accession ID: 84N19260.
BBSO-0230.
NAS 1.26:173359.
NASA-CR-173359.

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