Comprehensive exploration of late-type stars in the far-ultraviolet

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:7150011

Bennett, J O

Over the past decade, the international Ultraviolet Explorer (IUE) has obtained nearly 2500 low-dispersion (FWHM approx. 6 A), far-ultraviolet (1150-2000 A), emission-line spectra from more than 600 late-type (F through M) stars. During the past 5 years, the Solar Mesosphere Explorer (SME) has obtained daily full-disk scans of the Sun over a comparable wavelength range and with comparable resolution (1150-1700 A; FWHM approx. = 7.5 A). A comprehensive analysis of late-type stars, taking advantage of both the IUE and SME data sets, was made. To insure that the data base is internally self-consistent, techniques were developed for automated fitting of continuum intensities and emission-line fluxes. These techniques were applied to measure as many as 20 distinct emission features in each of the 2350 stellar spectra, and 1500 solar spectra, representing a total of some 60,000 line flux measurements. The author examines far-ultraviolet emissions as a function of stellar type and confirms the existence of the Linsky and Haisch (1978) dividing line between coronal and noncoronal giants. Flux-flux diagrams were constructed after the manner of Ayres, Marstad, and Linsky (1981), finding that far-ultraviolet emissions separate into a chromospheric group and a transition-zone group. Finally, far-ultraviolet variability of several stars that have been frequently observed during the ten-year history of the IUE were examined.

• Research Organization: Colorado Univ., Boulder (USA)
• OSTI ID: 7150011
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DATA ANALYSIS
DATA BASE MANAGEMENT
ELECTROMAGNETIC RADIATION
EMISSION SPECTRA
FAR ULTRAVIOLET RADIATION
MANAGEMENT
RADIATIONS
SPECTRA
STARS
ULTRAVIOLET RADIATION
VARIATIONS