CCD photometry of the RR Lyrae stars in NGC 121 and the distance to the Small Magellanic Cloud

1988 ◽  
Vol 96 ◽  
pp. 872 ◽  
Author(s):  
Alistair R. Walker ◽  
Peter Mack
2017 ◽  
Vol 473 (3) ◽  
pp. 3131-3146 ◽  
Author(s):  
T. Muraveva ◽  
S. Subramanian ◽  
G. Clementini ◽  
M.-R. L. Cioni ◽  
M. Palmer ◽  
...  

2004 ◽  
Vol 193 ◽  
pp. 124-127
Author(s):  
Tomasz Mizerski

AbstractI have performed a detailed analysis of multiperiodic RR Lyr stars of the Galactic Bulge and the Small Magellanic Cloud. In the rich OGLE-II database on the Galactic Bulge objects I detected more than 2500 RR Lyr stars, with almost 600 of them exhibiting multiperiodic behavior of various, sometimes unique, kinds. Many of them can only be explained by excitation of nonradial modes. There are two major, striking differences between the two discussed stellar systems: the incidence rate of RRd double mode pulsators is over 30 times higher in the SMC than in the Galactic Bulge, and there are more than twice as many Blazhko stars in the Galactic Bulge as in the SMC.


1993 ◽  
Vol 139 ◽  
pp. 349-356
Author(s):  
H.A. Smith ◽  
N.A. Silbermann ◽  
S.R. Baird ◽  
J.A. Graham

AbstractWe report results of a new photographic survey of variable stars in a 1 x 1.3 degree region near the Northeast Arm of the Small Magellanic Cloud. We have discovered 133 new variable stars in this field and have determined periods and B lightcurves for 78 new and 72 previously known variables. At periods shorter than about 3 days, the Cepheid period-luminosity relation splits into two sequences. The brighter sequence is believed to be populated by stars pulsating in the first overtone radial mode, wherecis the fainter sequence is populated by fundamental mode pulsators. The peak in the Cepheid period-frequency distribution occurs near a period of 1.8 days. The surface density of RR Lyrae stars in this field is comparable to that in an outlying SMC field near NGC 121.


2003 ◽  
Vol 598 (1) ◽  
pp. 597-609 ◽  
Author(s):  
C. Alcock ◽  
D. R. Alves ◽  
A. Becker ◽  
D. Bennett ◽  
K. H. Cook ◽  
...  

Star Clusters ◽  
1980 ◽  
pp. 347-348 ◽  
Author(s):  
James E. Hesser ◽  
James M. Nemec ◽  
Patricio P. Ugarte

2000 ◽  
Vol 176 ◽  
pp. 172-175 ◽  
Author(s):  
G. Clementini ◽  
A. Bragaglia ◽  
L. Di Fabrizio ◽  
E. Carretta ◽  
R. G. Gratton

AbstractThe Large Magellanic Cloud (LMC) is widely considered a corner-stone of the astronomical distance scale. However, a difference of 0.2−0.3 mag exists in its distance as predicted by the short and long distance scales. Distances to the LMC from Population II objects are founded on the RR Lyrae variables. We have undertaken an observational campaign devoted to the definition of the average apparent luminosity, and to the study of the mass–metallicity relation for RR Lyrae stars in the bar of the LMC. These are compared with analogous quantities for cluster RR Lyrae stars. The purpose is to see whether an intrinsic difference in luminosity, possibly due to a difference in mass, might exist between field and cluster RR Lyrae stars, which could be responsible for the well-known dichotomy between short and long distance scales. Preliminary results are presented on the V and B − V light curves, the average apparent visual magnitude, and the pulsational properties of 102 RR Lyrae stars in the bar of the LMC, observed at ESO in January 1999. The photometric data are accurately tied to the Johnson photometric system. Comparison is presented with the photometry of RR Lyrae stars in the bar of the LMC obtained by the MACHO collaboration (Alcock et al. 1996). Our sample includes 9 double-mode RR Lyrae stars selected from Alcock et al. (1997) for which an estimate of the metal abundance from the ΔS method is presented.


2019 ◽  
Vol 490 (3) ◽  
pp. 4254-4270 ◽  
Author(s):  
Jillian R Neeley ◽  
Massimo Marengo ◽  
Wendy L Freedman ◽  
Barry F Madore ◽  
Rachael L Beaton ◽  
...  

ABSTRACT RR Lyrae stars have long been popular standard candles, but significant advances in methodology and technology have been made in recent years to increase their precision as distance indicators. We present multiwavelength (optical UBVRcIc and Gaia G, BP, RP; near-infrared JHKs; mid-infrared [3.6], [4.5]) period–luminosity–metallicity (PLZ), period–Wesenheit–metallicity (PWZ) relations, calibrated using photometry obtained from the Carnegie RR Lyrae Program and parallaxes from the Gaia second data release for 55 Galactic field RR Lyrae stars. The metallicity slope, which has long been predicted by theoretical relations, can now be measured in all passbands. The scatter in the PLZ relations is on the order of 0.2 mag, and is still dominated by uncertainties in the parallaxes. As a consistency check of our PLZ relations, we also measure the distance modulus to the globular cluster M4, the Large Magellanic Cloud and the Small Magellanic Cloud, and our results are in excellent agreement with estimates from previous studies.


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