The evolutionary state of UU Herculis stars

Journal Article · Mon May 01 00:00:00 EDT 1989 · Publications of the Astronomical Society of the Pacific; (USA)

DOI:https://doi.org/10.1086/132461· OSTI ID:5398659

Fernie, J D; Sasselov, D D ^[1]

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1. David Dunlap Observatory, Richmond Hill (Canada)

UU Her stars are often considered to be postasymptotic-giant-branch stars, which in turn implies that they should be in a state of rapid blueward evolution in the H-R diagram. A recent reviewer of theoretical models suggests an increase in effective temperature at the rate of 10 K to 40 K per year. Measurements of the (B-V) color indices of these stars over as much as 35 years, and the pulsational period of UU Her itself over 83 years are examined, and no evidence is found for detectable change in either of these quantities. This is found to constrain any rate of effective temperature change to less than 0.5 K per year and, therefore, it is concluded that most likely the UU Her stars are not post-AGB stars. 26 refs.

• OSTI ID: 5398659
• Journal Information: Publications of the Astronomical Society of the Pacific; (USA), Vol. 101; ISSN 0004-6280
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
SUPERGIANT STARS
STAR EVOLUTION
COLOR
HERTZSPRUNG-RUSSELL DIAGRAM
OSCILLATIONS
TEMPERATURE MEASUREMENT
DIAGRAMS
GIANT STARS
OPTICAL PROPERTIES
ORGANOLEPTIC PROPERTIES
PHYSICAL PROPERTIES
STARS
640102* - Astrophysics & Cosmology- Stars & Quasi-Stellar
Radio & X-Ray Sources