Energy Citations Database

Bibliographic Citation

 
Document PDF 0 K   View Document or Access Individual Pages  -   search, view and/or download individual pages
Title Theoretical mean colors for RR Lyrae variables. [Computer code, variable Eddington radiation approximation]
Creator/Author Davis, C.G. ; Cox, A.N.
Publication Date1978 Jan 01
OSTI IdentifierOSTI ID: 6652084
Report Number(s)LA-UR-78-1511; CONF-780690-1
DOE Contract NumberW-7405-ENG-36
Resource TypeConference
Specific TypeTechnical Report
Resource RelationConference: Conference on current problems in stellar pulsation instabilities, Greenbelt, MD, USA, 1 Jun 1978
Research OrgLos Alamos Scientific Lab., NM (USA)
Subject71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; STAR MODELS; HYDRODYNAMICS; VARIABLE STARS; COLOR; TEMPERATURE MEASUREMENT; ABSORPTION; COMPUTER CODES; EDDINGTON THEORY; PHASE STUDIES; FLUID MECHANICS; MATHEMATICAL MODELS; MECHANICS; OPTICAL PROPERTIES; ORGANOLEPTIC PROPERTIES; PHYSICAL PROPERTIES; STARS
Description/Abstract A hydrodynamically pulsating 0.6 M/sub solar/ model of a typical RR Lyrae variable was studied with a radiation transport-hydrodynamic computer program to predict theoretical T/sub e/ and colors at many phases and to find the proper methods for getting mean colors and the consequent mean effective temperatures. The variable Eddington radiation approximation method was used with gray and with multifrequency absorption coefficients to represent the radiation flow in the outer optically thin layers. Comparison between observed and computed B-V colors indicates that these low Z Population II models are reasonably accurate using King 1A composition opacities. The well known Oke, Giver, and Searle relation between B-V and T/sub e/ is reproduced. Mean colors are found by four different averaging methods. The method that gives a mean color and the mean T/sub e/ closest to the nonpulsating model was the separate intensity means of B and V, just as the case for previous studies of classical Cepheids. The best mean for T/sub e/, which is known for all pulsation phases from four color observations of real RR Lyrae variables or from the calculated model, is a time average of T/sub e/ without any weighting function.
Country of PublicationUnited States
LanguageEnglish
FormatSize: Pages: 16
AvailabilityDep. NTIS, PC A02/MF A01.
System Entry Date2008 Dec 01

Top