scholarly journals The Absolute Magnitudes of the RR Lyrae Stars

1971 ◽  
Vol 2 ◽  
pp. 771-776
Author(s):  
Richard Woolley
Keyword(s):  
Classical Method ◽  
Variable Stars ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Pulsating Variable Stars ◽  
Stellar Diameters ◽  
Cepheid Variables ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Lyrae Stars

The absolute magnitudes of pulsating variable stars, both RR Lyrae stars and Cepheid variables, may be assessed from observation in three ways: by the classical method of statistical parallaxes, by their occurrence in star clusters whose distance is otherwise known, particularly by ascertaining the position of the main sequence in the HR diagram, and by the Baade-Wesselink method of determining stellar diameters.As regards the first of these, the method of statistical parallaxes, the RR Lyrae stars lend themselves to this better than do the Cepheid variables, because the velocities relative to the Sun are so much larger. RR Lyrae radial velocities are frequently as high as 200 km/sec or even 300 km/sec, and as many of the stars lie at distances between 1000 and 1500 pc the proper motions of the transverse velocities may be expected to be as high as 0”.050 per annum. And, indeed, many investigations have been made recently, among which one may mention those by Plaut, by van Herk, and by the Royal Greenwich Observatory.

On the absolute magnitudes of RR Lyrae stars

1986 ◽  
Vol 307 ◽  
pp. L9 ◽  
Author(s):  
T. G., III Barnes ◽  
S. L. Hawley
Keyword(s):  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Lyrae Stars

scholarly journals The absolute magnitudes of RR Lyrae stars – III. DH Peg ⋆

1990 ◽  
Vol 242 (4) ◽  
pp. 685-691 ◽  
Author(s):  
J. A. Fernley ◽  
I. Skillen ◽  
R. F. Jameson ◽  
A. J. Longmore
Keyword(s):  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Lyrae Stars

scholarly journals The absolute magnitudes of RR Lyrae stars – II. DX Delphini⋆

1989 ◽  
Vol 241 (2) ◽  
pp. 281-294 ◽  
Author(s):  
I. Skillen ◽  
J. A. Fernley ◽  
R. F. Jameson ◽  
A. E. Lynas-Gray ◽  
A. J. Longmore
Keyword(s):  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
The Absolute ◽  
Absolute Magnitudes ◽  
Lyrae Stars

scholarly journals Turnoffs and Ages of Globular Clusters

1988 ◽  
Vol 126 ◽  
pp. 635-636
Author(s):  
F. Buonanno ◽  
C. E. Corsi ◽  
F. Fusi Pecci
Keyword(s):  
Globular Clusters ◽  
Horizontal Branch ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
The Absolute ◽  
The Difference ◽  
Absolute Magnitudes ◽  
Lyrae Stars ◽  
The Way

The way to arrive at (even relative) ages for globular clusters involves the determination of their (relative) distances. We would like to see a theory which would fit the absolute magnitudes of RR Lyrae stars as determined from observations (Sandage effect). We have examined a sample of 17 CM diagrams of galactic globular clusters, 11 of which were observed at ESO and reduced with the program, ROMAFOT and 6 of which were taken from the literature. In Fig. 1 the difference in bolometric magnitude between the turnoff point and the location of the zero-age horizontal branch (ZAHB), δV RRTO (bo1) is plotted versus [Fe/H]. It turns out that δV RRTO ≃ δ RRTO (bo1) + 0.1 = 3.56 ±0.15. We are faced with the problem of determining how the horizontal branch scales with metallicity in order to understand the constant value of 3.56 in this relation.

scholarly journals Cepheid Pulsation Theory and Multiperiodic Cepheid Variables

1976 ◽  
Vol 29 ◽  
pp. 115-131
Author(s):  
A. N. Cox ◽  
J. P. Cox
Keyword(s):  
Variable Stars ◽  
Radial Pulsation ◽  
Rr Lyrae Stars ◽  
The Third ◽  
The Past ◽  
Rr Lyrae ◽  
Cepheid Variables ◽  
Theory Calculation ◽  
Lyrae Stars ◽  
Radial Pulsations

In this review of the situation with regard to the multiperiodic Cepheid variables, our subject matter is divided into four parts. The first discusses general causes of pulsation of Cepheids and other variable stars, and their locations on the H-R diagram. For this section we draw upon the work during the past 10-15 years of J. P. Cox, Baker, Kippenhahn, A. N. Cox, King, Christy, Castor, Stobie, Stellingwerf, Davey, Iben, and Tuggle, mostly with the small amplitude linear nonadiabatic radial pulsation theory. In the second section we review the linear adiabatic and nonadiabatic theory calculation of radial pulsation periods and their application to the problem of masses of double-mode Cepheids. Contributions discussed are by Cogan, J. P. Cox, King, Stellingwerf, Petersen, Hansen, and Ross. Periodic solutions, and their stability, of the nonlinear radial pulsation equations for Cepheids and RR Lyrae stars are considered in the third section. This research has been done by Stellingwerf with previous development of methods by Baker and von Sengbusch and current work by A. N. Cox and Davey at Los Alamos. In the last section we give the latest results on nonlinear, nonperiodic, radial pulsations for Cepheids and RR Lyrae stars. This work has been done by Stellingwerf, King, A. N. Cox, J. P. Cox, and Davey.

scholarly journals Cepheid Variables in Ecliping Binary Systems

2005 ◽  
Vol 13 ◽  
pp. 460-460
Author(s):  
Douglas Welch
Keyword(s):  
Binary Systems ◽  
Variable Stars ◽  
Eclipsing Binaries ◽  
Type I ◽  
Rr Lyrae Stars ◽  
Additional Information ◽  
Rr Lyrae ◽  
Future Success ◽  
Cepheid Variables ◽  
Lyrae Stars

Microlensing surveys of the Large and Small Magellanic Clouds have revealed the existence of Type I and II Cepheid variable stars in eclipsing binary systems. In this review I will summarize the state of the known published and unpublished observations of these systems describe what has been learned to date and discuss what the prospects are for extracting additional information from the known systems using future observations. This review will also discuss the known state of searches for RR Lyrae stars in both spectroscopic and eclipsing binaries and suggest strategies for future success in detecting such systems.

scholarly journals Optical and Near-infrared Pulsation Properties of RR Lyrae and Population II Cepheid Variables in the Messier 15 Globular Cluster

2021 ◽  
Vol 922 (1) ◽  
pp. 20
Author(s):  
Anupam Bhardwaj ◽  
Marina Rejkuba ◽  
G. C. Sloan ◽  
Marcella Marconi ◽  
Soung-Chul Yang
Keyword(s):  
Globular Cluster ◽  
Near Infrared ◽  
Variable Stars ◽  
Log P ◽  
Distance Modulus ◽  
Distance Measurements ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
Cepheid Variables ◽  
Lyrae Stars

Abstract Messier 15 (NGC 7078) is an old and metal-poor post core-collapse globular cluster that hosts a rich population of variable stars. We report new optical (gi) and near-infrared (NIR, JK s ) multi-epoch observations for 129 RR Lyrae, 4 Population II Cepheids (3 BL Herculis, 1 W Virginis), and 1 anomalous Cepheid variable candidate in M15 obtained using the MegaCam and the WIRCam instruments on the 3.6 m Canada–France–Hawaii Telescope. Multi-band data are used to improve the periods and classification of variable stars, and determine accurate mean magnitudes and pulsational amplitudes from the light curves fitted with optical and NIR templates. We derive optical and NIR period–luminosity relations for RR Lyrae stars which are best constrained in the K s band, m K s = − 2.333 ( 0.054 ) log P + 13.948 ( 0.015 ) with a scatter of only 0.037 mag. Theoretical and empirical calibrations of RR Lyrae period–luminosity–metallicity relations are used to derive a true distance modulus to M15: 15.196 ± 0.026 (statistical) ± 0.039 (systematic) mag. Our precise distance moduli based on RR Lyrae stars and Population II Cepheid variables are mutually consistent and agree with recent distance measurements in the literature based on Gaia parallaxes and other independent methods.

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