Open AccessThe RR Lyrae period– K ‐luminosity relation for globular clusters: an observational approach ★
Author(s) -
Sollima A.,
Cacciari C.,
Valenti E.
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2006.10962.x
Subject(s) - physics , rr lyrae variable , globular cluster , astrophysics , distance modulus , photometry (optics) , cepheid variable , astronomy , large magellanic cloud , metallicity , variable star , apparent magnitude , absolute magnitude , stars
The period–metallicity– K ‐band luminosity (PL K ) relation for RR Lyrae stars in 15 Galactic globular clusters and in the Large Magellanic Cloud (LMC) globular cluster Reticulum has been derived. It is based on accurate near‐infrared ( K ) photometry combined with Two‐Micron All‐Sky Survey (2MASS) and other literature data. The PL K relation has been calibrated and compared with the previous empirical and theoretical determinations in literature. The zero point of the absolute calibration has been obtained from the K magnitude of RR Lyr whose distance modulus has been measured via trigonometric parallax with Hubble Space Telescope ( HST ). Using this relation, we obtain a distance modulus to the LMC of ( m − M ) 0 = 18.54 ± 0.15 mag , in good agreement with recent determinations based on the analysis of Cepheid variable stars.