The Distance to the Galactic Center Obtained by Infrared Photometry of RR Lyrae Variables

We report K-band photometry of 58 RR Lyraes in the field of Baade's Window (l=1°, b=-3.9°). Using a metallicity- and reddening-insensitive relation between MK and log P for RR Lyraes in this field and in another at l=0°, b=-12° studied by Fernley et al. [MNRAS, 226, 927 (1987)], we derive the distance to the galactic center. Using the distance scale of Carney et al. [ApJ, 386, 663 (1992)], we find R0=7.8±0.4 kpc. Adjusting that distance scale's zero point to yield an LMC distance modulus (m-M)0=18.5 mag results in R0=8.9±0.5 kpc. Including the systematic uncertainties from the two different distance scales results in R0=8.3±1.0 kpc. We discuss some implications for the star formation history in the bulge using the derived distances. © 1995 American Astronomical Society.

Carney, B. W., Fulbright, J. P., Terndrup, D. M., Suntzeff, N. B., & Walker, A. R

Carney, Bruce W||Fulbright, Jon P||Terndrup, Donald M||Suntzeff, Nicholas B||Walker, Alistair R

The Distance to the Galactic Center Obtained by Infrared Photometry of RR Lyrae Variables Academic Article