Absolute Magnitudes and Colors of RR Lyrae stars in DECam Passbands from Photometry of the Globular Cluster M5

Abstract

We characterize the absolute magnitudes and colors of RR Lyrae stars in the globular cluster M5 in the ugriz filter system of the Dark Energy Camera (DECam). We provide empirical Period-Luminosity (P-L) relationships in all 5 bands based on 47 RR Lyrae stars of the type ab and 14 stars of the type c. The P-L relationships were found to be better constrained for the fundamental mode RR Lyrae stars in the riz passbands, with dispersion of 0.03, 0.02 and 0.02 magnitudes, respectively. The dispersion of the color at minimum light was found to be small, supporting the use of this parameter as a means to obtain accurate interstellar extinctions along the line of sight up to the distance of the RR Lyrae star. We found a trend of color at minimum light with pulsational period that, if taken into account, brings the dispersion in color at minimum light to < 0.016 magnitudes for the (r-i), (i-z), and (r-z) colors. These calibrations will be very useful for using RR Lyrae stars from DECam observations as both standard candles for distance determinations and color standards for reddening measurements.

Accepted for publication in AJ

References in corpus (4)

• The Catalina Surveys Periodic Variable Star Catalog
• The Period-Luminosity Relation of RR Lyrae Stars in the SDSS Photometric System
• Metallicity Analysis of MACHO Galactic Bulge RR0 Lyrae stars from their Lightcurves
• Period-Color and Amplitude-Color Relations at Maximum and Minimum Light for RR Lyrae Stars in the SDSS Stripe 82 Region

Cited by in corpus (11)

• Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey
• Mapping the Interstellar Reddening and Extinction towards Baade's Window Using Minimum Light Colors of ab-type RR Lyrae Stars. Revelations from the De-reddened Color-Magnitude Diagrams
• A DECam View of the Diffuse Dwarf Galaxy Crater II: Variable Stars
• Identification of RR Lyrae stars in multiband, sparsely-sampled data from the Dark Energy Survey using template fitting and Random Forest classification
• Variable stars in Local Group Galaxies -- V. The fast and early evolution of the low-mass Eridanus II dSph galaxy
• Photometric-Metallicity and Distance Estimates for $\sim$70,000 RR Lyrae Stars from the Zwicky Transient Facility
• Photometric calibration in u-band using blue halo stars
• High-cadence stellar variability studies of RR Lyrae stars with DECam: New multi-band templates
• An excess of luminous white dwarfs in the peculiar Galactic globular cluster NGC 2808
• Zwicky Transient Facility and Globular Clusters: The RR Lyrae gri-Band Period-Luminosity-Metallicity and Period-Wesenheit-Metallicity Relations
• Optical and near-infrared pulsation properties of RR Lyrae and Population II Cepheid variables in the Messier 15 globular cluster