Neutral sodium D/sub 2/ line in late-type stars
Thesis/Dissertation
·
OSTI ID:5937227
An atlas of high spectral resolution Na I D/sub 2/ and HI alpha spectra is presented for 33 dwarfs giants, and supergiants covering a range of spectral types from F5 to M4.5. These spectra form the basis of a study in which the effects of a stellar chromosphere on the Na I D/sub 2/ profile are investigated. The analysis of line profile parameters yields the following results: (i) a relationship between the line width and the luminosity for the giants and supergiants does not exist for Na I D/sub 2/ as has been observed for Ca II K core emission (Wilson and Bappu, 1957) and H I alpha (Kraft et al., 1964). This reinforces the concept that the mechanism responsible for the Wilson-Bappu effect does not operate in the high photosphere of these stars. (ii) The correlation between Na I D/sub 2/ line width and luminosity for the F through K dwarfs is explained in terms of differences in effective temperature and surface gravity along with the main sequences. The dMe stars exhibit central reversals in the Na I D lines. (iii) The method of Steinitz et al. (1975) has been used to measure Doppler widths for H I alpha and Na I D/sub 2/ lines under the assumption of a constant properties atmosphere. The H I alpha measurements imply supersonic nonthermal velocities for the giants and supergiants.
- Research Organization:
- New Mexico State Univ., Las Cruces (USA)
- OSTI ID:
- 5937227
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ALPHA SPECTRA
ATMOSPHERES
DWARF STARS
ELEMENTS
GIANT STARS
LUMINOSITY
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SODIUM
SOLAR ATMOSPHERE
SPECTRA
STARS
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALI METALS
ALPHA SPECTRA
ATMOSPHERES
DWARF STARS
ELEMENTS
GIANT STARS
LUMINOSITY
METALS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SODIUM
SOLAR ATMOSPHERE
SPECTRA
STARS