A search for variable stars in the globular cluster M3
Kaluzny, J.; Hilditch, R. W.; Clement, C.; Rucinski, S. M.
Abstract:
We describe here the 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 straggler stars (BSS). 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 a magnitude to the blue of the base of the red giant branch. V238 is a likely descendant 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, seven type c and two double-mode pulsators. We used equations that relate the physical properties of RRc stars to their pulsation periods and Fourier parameters in order to derive masses, luminosities, temperatures and helium parameters for five of the RRc stars. We also tested equations that relate the [Fe/H], M_V and temperature of RRab stars to pulsation period and Fourier parameters. We derived [Fe/H]=-1.42 in good agreement with spectroscopic determinations.

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The paper (PDF) "A search for variable stars in the globular cluster M3"
Kaluzny, J.; Hilditch, R. W.; Clement, C.; Rucinski, S. M., Monthly Notices of the Royal Astronomical Society, Volume 296, Issue 2, pp. 347-358
Template image (FITS)


Table 1:Basic properties of variable stars in M3
Star Xa Ya Period [days] Vmax Δ V B-V PMb Typec V light-curved B light-curved Remarks
V1 0.5206250 15.6899 1.1461 RR ab V01.dat
V10 0.5695185 15.6803 0.9203 RR ab V10.dat
V11 0.5078918 15.6861 1.3357 RR ab V11.dat
V12 0.3178890 15.6198 0.5156 RR c V12.dat
V13 0.4799 15.6803 0.7072 RR ab V13.dat
V14 0.6359019 15.5658 0.8556 RR ab V14.dat
V15 0.5300794 15.6686 1.1034 RR ab V15.dat
V17 0.5757 15.6939 0.6978 RR ab V17.dat
V18 0.5163623 15.7534 1.1492 RR ab V18.dat
V23 0.5953756 15.6326 0.7293 RR ab V23.dat
V34 0.5591012 15.6743 0.9635 RR ab V34.dat
V35 0.5296 15.6530 1.1796 RR ab V35.dat
V50 0.5130879 15.6861 0.5435 RR ab V50.dat
V51 0.5839818 15.6906 0.8461 RR ab V51.dat
V52 0.5162250 15.7067 1.1988 RR ab V52.dat
V53 0.5048878 15.7245 1.2088 RR ab V53.dat
V59 0.5888053 15.6854 0.8337 RR ab V59.dat
V61 0.5209312 15.7021 1.2253 RR ab V61.dat
V62 0.6524077 15.6313 0.4796 RR ab V62.dat
V63 0.5704164 15.6997 0.8489 RR ab V63.dat
V64 0.6054588 15.6972 0.6883 RR ab V64.dat
V65 0.6683397 15.5335 0.9460 RR ab V65.dat
V66 0.6191 15.6645 0.6463 RR ab V66.dat
V67 0.5683609 15.7267 0.5535 RR ab V67.dat
V68 0.356 15.6359 0.348 RR ab V68.dat
V69 0.5665878 15.7009 0.9097 RR ab V69.dat
V70 0.4865 15.3660 0.3434 RR ab V70.dat
V74 0.4921441 15.7237 1.2526 RR ab V74.dat
V75 0.3140790 15.6544 0.4809 RR c V75.dat
V79 0.358 15.7122 0.313 RR d V79.dat
V84 0.5957289 15.6733 0.7246 RR ab V84.dat
V90 0.5170334 15.7305 1.1658 RR ab V90.dat
V92 0.5035553 15.7330 0.9990 RR ab V92.dat
V97 0.3349289 15.6886 0.4000 RR c V97.dat
V104 0.5699231 15.6040 1.3070 RR ab V104.dat
V105 0.2877427 15.6014 0.3264 RR c? V105.dat
V106 0.5471593 15.7183 0.6389 RR ab V106.dat
V107 0.3090351 15.6580 0.5138 RR c V107.dat
V118 0.4993807 15.7424 0.8754 RR ab V118.dat
V124 0.7524328 15.5423 0.3371 RR ab V124.dat
V126 0.3484043 15.6348 0.4019 RR c V126.dat
V203 0.28964 15.5877 0.1758 RR c? V203.dat
V237 0.04010 17.90 0.20 0.15 SX -
V238 0.4983 17.25 0.10 0.58 Ecl? -
a Pixel coordinate in the template image
b Proper motion membership status — Y - member, N - field star, U - unknown
c Variable type

RR - RR Lyrae type pulsator; SX - SX Phoenicis type pulsator; Ecl - eclipsing variable

d Data columns:
  1. HJD - 2 450 000.0
  2. V magnitude
  3. error of magnitude (dummy points are maked with the error=9.999)