The Baade-Wesselink method and the distances to RR Lyrae stars. V - The field star DH Pegasi

We have applied the surface brightness version of the Baade-Wesselink method to the nearby moderatel metal-rich ([Fe/H] = -0.79) c-type RR Lyrae variable DH Pegasi, utilizing simultaneous VRIJHK photometry and radial velocities derived from high-resolution spectroscopy. We derived an intensity averaged <Mv> = 0.93 ± 0.18 mag for this star from the K, V - K magnitude-color combination. We find that the optical colors yield effective temperatures that are too large in the expansion phase of the pulsation cycle, leading to a phasing problem similar to that encountered earlier in the ab-type stars. We summarize the results for this and previous investigations and derive values of intensity averaged <Mv> = 0.89 ± 0.14 mag and <Mbol> = 0.85 &plusmn 0.15 mag for RR Lyrae stars, assuming that our program stars represent typical variables. We briefly discuss the implications of these values upon the distances and ages of globular clusters, the distance to the Galactic center, and the distances to M31 and the Magellanic Clouds.