A Search for Red Variable Stars in the Magellanic Clouds

1971 ◽  
pp. 74-78 ◽  
Author(s):  
T. Lloyd Evans
Keyword(s):  
Variable Stars ◽  
Magellanic Clouds

scholarly journals New results on OGLE Cepheids and PL relations in the LMC and SMC

2004 ◽  
Vol 193 ◽  
pp. 75-82
Author(s):  
A. Udalski
Keyword(s):  
Gravitational Lensing ◽  
Variable Stars ◽  
Magellanic Clouds ◽  
Photometric Data ◽  
Second Phase ◽  
Internet Archive ◽  
Pulsating Stars ◽  
Third Phase ◽  
Pulsating Variable Stars ◽  
Star Field

AbstractWe present results of the search for pulsating variable stars in the Magellanic Cloud fields covering central parts of these galaxies. The data were collected during the second phase of the Optical Gravitational Lensing Experiment survey (OGLE-II) from 1997 to 2000. In total, several thousand pulsating stars (Cepheids, RR Lyr) were found in both Magellanic Clouds. The photometric data of all objects are available to the astronomical community from the OGLE Internet archive. We present basic properties of pulsating stars in the Magellanic Clouds including Period–Luminosity relations for Cepheids. We also discuss observational prospects for the pulsating star field in the ongoing third phase of the OGLE project (OGLE-III) which started in 2001.

scholarly journals CCD photometry of variable stars in the Magellanic Clouds -II. The eclipsing binary HV 2274

1992 ◽  
Vol 258 (3) ◽  
pp. 527-532 ◽  
Author(s):  
R. D. Watson ◽  
S. R. D. West ◽  
W. Tobin ◽  
A. C. Gilmore
Keyword(s):  
Variable Stars ◽  
Magellanic Clouds ◽  
Ccd Photometry ◽  
Eclipsing Binary

scholarly journals Spectroscopy of Overluminous Cepheids in the Magellanic Clouds

1984 ◽  
Vol 108 ◽  
pp. 223-224
Author(s):  
Horace A. Smith ◽  
Leo Connolly
Keyword(s):  
Globular Cluster ◽  
Large Magellanic Cloud ◽  
Variable Stars ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Small Magellanic Cloud ◽  
Single Star ◽  
Rr Lyrae ◽  
Short Period ◽  
The Galaxy

The Small Magellanic Cloud is known to contain types of short period Cepheid variable stars not yet discovered in either the Large Magellanic Cloud or, with the exception of a single star, in the Galaxy. These variables can be divided into two categories: anomalous Cepheids and Wesselink-Shuttleworth (WS) stars. The former, which have also been found in dwarf spheroidal systems and in the globular cluster NGC 5466, have periods of 0.4–3 days, but average 0.7–1.0 mag. brighter than RR Lyrae and BL Her stars of equal period. The stars we call WS stars have periods less than about 1.1 day and, at MV = −1 to −2, are brighter than anomalous Cepheids of equal period.

scholarly journals First CCD observations of Magellanic Cloud variable stars from the Mt John University Observatory, New Zealand

1991 ◽  
Vol 148 ◽  
pp. 381-381
Author(s):  
William Tobin ◽  
A. C. Gilmore ◽  
Alan Wadsworth ◽  
S.R.D. West
Keyword(s):  
New Zealand ◽  
Evaluation Process ◽  
Variable Stars ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Ccd Observations ◽  
Differential Photometry

Late in 1988 the Mt John University Observatory acquired a cryogenic CCD system from Photometrics Ltd (Tucson). The chip is a Thomson CSF TH7882 CDA comprising 384 × 576 pixels. As part of the evaluation process, we have begun two differential photometry programs of the Magellanic Clouds using the Mt John 0.6m Boller & Chivens telescope. On this telescope each CCD pixel corresponds to 0.6 arcsec. Mt John's southerly latitude (44°S) permits year-round observations of the Clouds.The first program concerns B, V and I photometry of five blue eclipsing binaries selected, on the basis of Gaposchkin's (1970, 1977) photographic light curves, to have roughly equal components with minimal interaction. HV 12634 has also been observed for comparison with the CCD light curves published by Jensen et al. (1988). Fig. 1 shows the B observations so far obtained for HV 1761, but the reduction is preliminary, being based on aperture-integrated magnitudes. The field is populous, and a final reduction will require use of a crowded-field reduction package such as ROMAFOT.

scholarly journals Period Changes in Magellanic Cloud Cepheids

1984 ◽  
Vol 108 ◽  
pp. 227-228
Author(s):  
H. Deasy ◽  
P. A. Wayman
Keyword(s):  
South African ◽  
Variable Stars ◽  
Period Change ◽  
Magellanic Clouds ◽  
Rate Of Change ◽  
Data Sets ◽  
Fractional Change ◽  
Rates Of Change ◽  
Observatory Data ◽  
Irregular Period

It has been found possible to obtain information on period change in data on 115 cepheid variable stars in the Magellanic Clouds (84 LMC cepheids and 31 SMC cepheids). Harvard Observatory data of the period 1910 to 1950 (collated by Payne-Gaposchkin and Gaposchkin) are combined with Dunsink Observatory observations carried out by C.J. Butler in 1966/67 and with South African Astronomical Observatory observations covering the years 1975–1977 by Martin, Thomas, Carter and Davies to derive mean periods for the intervals between the various data sets. Using these new periods in conjunction with the very accurate Harvard periods, seperate estimates of the time averaged fractional change of period per day, d/dt (ln P), with corresponding estimated errors, could be evaluated for two epochs, one around 1950 and the other around 1971. It was found that 70 stars give rates of change of period that are not significantly different from zero, that 20 stars have two values of rate of change of period that are in agreement at the two epochs (indicative of secular period change), while 22 stars give two disparate values of rate of change of period (indicative of irregular period changes).

scholarly journals RR Lyrae Variable Stars and the Distance Scale

1978 ◽  
Vol 80 ◽  
pp. 53-57
Author(s):  
S. V. M. Clube ◽  
J. A. Dawe
Keyword(s):  
Galactic Halo ◽  
Galactic Center ◽  
Variable Stars ◽  
Magellanic Clouds ◽  
Solar Neighborhood ◽  
Royal Greenwich Observatory ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Lyrae Stars ◽  
Kinematical Parameters

A statistical parallax algorithm (Clube and Dave, 1978a,b), using the technique of maximum likelihood, has been applied to a set of 103 ‘ab’ - RR Lyrae stars in the solar neighborhood (r 2<kpc), using observational data from the Royal Greenwich Observatory Bulletins. A second set of 130 ‘ab’ - RR Lyrae stars has been kindly supplied to us by Dr. A. Heck (Université de Liège) to permit a comparison between our analyses. The purpose of this investigation was:(a) to investigate the variations of kinematical parameters and absolute luminosities of these stars as functions of Preston's index ΔS and of log (Period).(b) to identify those RR Lyrae stars in the solar neighborhood which most closely resemble those in the galactic halo, those near the galactic center, and those in the Magellanic Clouds.

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