Search for Variable Stars in the Globular Cluster M3

Abstract

We describe here results of a photometric time-sequence survey of the globular cluster M3 (NGC 5272), in a search for contact and detached eclipsing binary stars. We have discovered only one likely eclipsing binary and one SX Phe type star in spite of monitoring 4077 stars with $V<20.0$ and observing 25 blue stragglers. The newly identified SX Phe star, V237, shows a light curve with a variable amplitude. Variable V238 shows variability either with a period of 0.49 d or with a period of 0.25 d. On the cluster colour-magnitude diagram, the variable occupies a position a few hundredths of magnitude to the blue of the base of the red giant branch. V238 is a likely descendent of a binary blue straggler. As a side result we obtained high quality data for 42 of the previously known RR Lyrae variables, including 33 of Bailey type ab, 7 type c and 2 double-mode pulsators. We used equations that relate the physical properties of RRc stars to their pulsation periods and Fourier parameters to derive masses, luminosities, temperatures and helium parameters for five of the RRc stars. One of the RRd stars (V79) has switched modes. In previous studies, it was classified as RRab, but our observations show that it is an RRd star with the first overtone mode dominating. This indicates blueward evolution on the horizontal branch.

21 pages including 14 figures, Latex, requires mn.sty, psfig.sty. Submitted, MNRAS

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Cited by in corpus (44)

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• Distances, ages, and epoch of formation of globular clusters
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• The MACHO Project 9 Million Star Color-Magnitude Diagram of the Large Magellanic Cloud
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• RR Lyrae Variables in the Globular Cluster M55. The First Evidence for Non Radial Pulsations in RR Lyr Stars
• Fourier analysis of non-Blazhko ab-type RR Lyrae stars observed with the Kepler space telescope
• Variable Stars in the Unusual, Metal-Rich Globular Cluster NGC 6441
• Globular Cluster Distance Determinations
• The Globular Cluster Omega Centauri and the Oosterhoff Dichotomy
• Empirical relations for cluster RR Lyrae stars revisited
• The RR Lyrae Period-Amplitude Relation as a Clue to the Origin of the Oosterhoff Dichotomy
• CCD Photometry of the Globular Cluster Omega Centauri. I. Metallicity of RR Lyrae Stars from Caby Photometry
• Stellar Archaeology in the Galactic halo with Ultra-Faint Dwarfs: VII. Hercules
• RR Lyrae stars in the Sagittarius dwarf galaxy: Period analysis
• Exploring the Leo II dSph I.: The Variable Star Content
• Overtone and multi-mode RR Lyrae stars in the globular cluster M3
• The MACHO Project Large Magellanic Cloud Variable Star Inventory. XIII. Fourier Parameters for the First Overtone RR Lyrae Variables and the LMC Distance
• Image-Subtraction Photometry of the Globular Cluster M3: identification of new double-mode RR Lyrae stars
• Clusters AgeS Experiment. RR Lyr Variables in the Globular Cluster NGC 6362
• Long-term photometric monitoring of RR Lyr stars in M3
• Linear nonadiabatic properties of SX Phoenicis variables
• Image-Subtraction Photometry of Variable Stars in the Field of the Globular Cluster NGC 6934
• Multicolour CCD photometry of the variable stars in globular cluster M3
• CCD Photometry of the Globlular Cluster NGC 5986 and its Post-Asymptotic-Giant-Branch and RR Lyrae Stars
• Time-Series Photometry of Globular Clusters: M62 (NGC 6266), the Most RR Lyrae-Rich Globular Cluster in the Galaxy?
• Physical parameters of the Small Magellanic Cloud RR Lyrae stars and the distance scale
• Photometric and radial-velocity time-series of RR Lyrae stars in M3: analysis of single-mode variables
• Spatial metallicity asymmetry in $\omega$ Centauri
• CCD Photometry of the globular cluster M2. RR Lyrae physical parameters and new variables
• M75, a Globular Cluster with a Trimodal Horizontal Branch. II. BV Photometry of the RR Lyrae Variables
• A Semi-Empirical Study of the Mass Distribution of Horizontal Branch Stars in M3 (NGC 5272)
• The outer-halo globular cluster NGC 6229. IV. Variable stars
• Detection of the evolutionary stages of variables in M3
• The Swift/UVOT Stars Survey. II. RR Lyrae Stars in M 3 and M 15
• BVI Photometric Variability Survey of M3
• Double-Mode Radial Pulsations among RR Lyrae Stars
• The Distance of the First Overtone RR Lyrae Variables in the MACHO LMC Database: A New Method to Correct for the Effects of Crowding
• Distances and ages of globular clusters using Hipparcos parallaxes of local subdwarfs
• The metallicity range of variables in M3
• The Changing Lightcurve of the Double-Mode RR Lyrae Variable Star V338 Boo
• A search for photometric variability towards the globular cluster M3 with the TWenty Inch Survey Telescope
• Caught in the Act: Observations of the Double-mode RR Lyrae V338 Boo During the Disappearance of a Pulsation Mode
• Warsaw Variability Surveys