The Absolute Magnitude of RR Lyrae Stars
Abstract
We derive the absolute magnitude of RR Lyrae stars by two independent maximumlikelihood estimations, using Hipparcos proper motion and parallax data, respectively. By applying the statistical parallax method to 99 Halo RR Lyrae stars, we obtain the mean absolute magnitude <M_V>= 0.69 +/ 0.10 at <[Fe/H]> = 1.58. Independently of this method, we furthermore derive the M_V  [Fe/H] relation from Hippparcos parallaxes for 125 RR Lyrae stars including negative ones by the method of Ratnatunga & Casertano. We obtain M_V = 0.91(+/ 0.88)+0.21(+/ 0.63)[Fe/H]. For 99 Halo RR Lyrae stars, <M_V> = 0.65 +/ 0.33 is also derived.
 Publication:

Hipparcos  Venice '97
 Pub Date:
 August 1997
 Bibcode:
 1997ESASP.402..639T