Period change similarities among the RR Lyrae Variables in Oosterhoff I and Oosterhoff II globular systems

Download
  1. Get@NRC: Period change similarities among the RR Lyrae Variables in Oosterhoff I and Oosterhoff II globular systems (Opens in a new window)
DOIResolve DOI: http://doi.org/10.1088/0004-6256/141/1/15
AuthorSearch for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for: ; Search for:
TypeArticle
Journal titleAstronomical Journal
Volume141
Issue1
Pages114; # of pages: 14
SubjectGalaxy: center; stars: abundances; stars: distances; stars: Population II; surveys
AbstractWe present period change rates (dP/dt) for 42 RR Lyrae variables in the globular cluster IC 4499. Despite clear evidence of these period increases or decreases, the observed period change rates are an order of magnitude larger than predicted from theoretical models of this cluster. We find that there is a preference for increasing periods, a phenomenon observed in most RR Lyrae stars in Milky Way globular clusters. The period change rates as a function of position in the period-amplitude plane are used to examine possible evolutionary effects in OoI clusters, OoII clusters, field RR Lyrae stars, and the mixed-population cluster. Centauri. It is found that there is no correlation between the period change rate and the typical definition of Oosterhoff groups. If the RR Lyrae period changes correspond with evolutionary effects, this would be in contrast to the hypothesis that RR Lyrae variables in OoII systems are evolved horizontal-branch stars that spent their zero-age horizontal-branch phase on the blue side of the instability strip. This may suggest that age may not be the primary explanation for the Oosterhoff types.
Publication date
LanguageEnglish
AffiliationNational Research Council Canada; NRC Herzberg Institute of Astrophysics
Peer reviewedYes
NPARC number19762622
Export citationExport as RIS
Report a correctionReport a correction
Record identifier8e0efd2a-cbf5-4d1b-9fbd-ea53dba1ac85
Record created2012-04-02
Record modified2016-05-09
Bookmark and share
  • Share this page with Facebook (Opens in a new window)
  • Share this page with Twitter (Opens in a new window)
  • Share this page with Google+ (Opens in a new window)
  • Share this page with Delicious (Opens in a new window)