Astronomy and Astrophysics – Astrophysics
Scientific paper
Feb 1991
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1991apj...367..524l&link_type=abstract
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 367, Feb. 1, 1991, p. 524-527. Research supported by NSERC.
Astronomy and Astrophysics
Astrophysics
44
Blue Stars, Cepheid Variables, Giant Stars, Horizontal Branch Stars, Stellar Evolution, Stellar Models, Stellar Oscillations, Variable Stars
Scientific paper
The observed secular period changes of RR Lyrae stars in five globular clusters have been compared with those predicted by synthetic models of the horizontal branch (HB). It is shown that most of the observed number distributions of the period change rate beta could be attributed to evolutionary effects, if the random observational error is of order + or - 0.07 days/Myr in beta as suggested by the observers. The model calculations indicate that the mean rate of period change in RR Lyrae stars in globular clusters depends sensitively on their HB type, as is the case for the period shift at a given effective temperature. The distinct bias toward positive period changes in M15 and Omega Cen is evidence that most HB stars in the Oosterhoff group II clusters pass through the instability strip from blue to red toward the end of their core helium burning phase. If confirmed by future observations, this is strong support for the Lee et al. (1990) explanation of the Sandage (1957) period-shift effect.
No associations
LandOfFree
Stellar evolution and period changes in RR Lyrae stars does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Stellar evolution and period changes in RR Lyrae stars, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stellar evolution and period changes in RR Lyrae stars will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1315786