RR Lyrae the Stellar Beacons of the Galactic Structure

Details RR Lyrae the Stellar Beacons of the Galactic Structure RR Lyrae the Stellar Beacons of the Galactic Structure

2011-08-26

arxiv.org/abs/1108.5372v2

Astronomy and Astrophysics

Astrophysics

Solar and Stellar Astrophysics

To appear in the Carnegie Observatories Astrophysics Series, volume 5

Scientific paper

We present some recent findings concerning the use of RR Lyrae as distance indicators and stellar tracers. We outline pros and cons of field and cluster RR Lyrae stars and discuss recent theoretical findings concerning the use of the Bailey (amplitude vs pulsation period) diagram to constrain the possible occurrence of Helium enhanced RR Lyrae stars. Nonlinear, convective RR Lyrae models indicate that the pulsation properties of RR Lyrae stars are minimally affected by the helium content. The main difference between canonical and He enhanced models is due to the increase in luminosity predicted by evolutionary models. Moreover, we focus our attention on the near-infrared Period-Luminosity (PL) relation of RR Lyrae and summarize observational evidence concerning the slope of the K-band PL relation in a few globulars (M92, Reticulum, M5, Omega Cen) covering a range in metallicity of ~1 dex. Current findings suggest that the slope has a mild dependence on the metal content when moving from the metal-poor to the metal-intermediate regime. Finally, we also discuss the use of RR Lyrae stars either to estimate (helium indicator: A-parameter) or to measure (absorption and emission lines) the helium content.

Affiliated with

Also associated with

No associations

Rating

RR Lyrae the Stellar Beacons of the Galactic Structure 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 RR Lyrae the Stellar Beacons of the Galactic Structure, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and RR Lyrae the Stellar Beacons of the Galactic Structure will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-502910