The Absolute Luminosity of RR Lyrae Variables

1988 ◽  
pp. 587-588
Author(s):  
C. Cacciari ◽  
G. Clementini ◽  
L. Prevot
Keyword(s):  
Rr Lyrae ◽  
The Absolute ◽  
Absolute Luminosity

scholarly journals Luminosity Classification of Be Stars by Balmer Line Narrow Band Photometry

1982 ◽  
Vol 98 ◽  
pp. 37-40
Author(s):  
Wolfgang Zeuge
Keyword(s):  
Narrow Band ◽  
Balmer Line ◽  
Be Stars ◽  
The Absolute ◽  
Absolute Luminosity

The absolute luminosity of most Be stars can be determined by using Balmer line narrow band photometry with an accuracy of about 0.4 mag. The few cases in which this method fails can be detected.

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 and the Age of the Galaxy

1989 ◽  
Vol 111 ◽  
pp. 121-140
Author(s):  
Allan Sandage
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Main Sequence ◽  
Absolute Magnitude ◽  
Cluster System ◽  
Apparent Magnitude ◽  
Rr Lyrae ◽  
Globular Cluster System ◽  
The Absolute ◽  
Absolute Magnitudes

AbstractIt is shown that the intrinsic spread in the absolute magnitudes of the RR Lyrae variables in a given globular cluster can reach 0.5 magnitudes at a given period or at a given color, due to luminosity evolution away from the zero age horizontal (ZAHB). The size of this intrinsic luminosity spread is largest in clusters of the highest metallicity.The absolute magnitude of the ZAHB itself also differs from cluster to cluster as a function of metallicity, being brightest in clusters of the lowest metallicity. Three independent methods of calibrating the ZAHB RR Lyrae luminosities each show a strong variation of MV(RR) with [Fe/H]. The pulsation equation of P<ρ>0.5 = Q(M,Te, L) used with the observed periods, temperatures, and masses of field and of cluster RR Lyraes gives the very steep luminosity-metallicity dependence of dMv(RR)/d[Fe/H] = 0.42. Main sequence fitting of the color-magnitude diagrams of clusters which have modern main-sequence photometry gives a confirming steep slope of 0.39. A summary of Baade-Wesselink MV(RR) values for field stars determined in four independent recent studies also shows a luminosity-metallicity dependence, but less steep with a slope of dMV(RR)/d[Fe/H] = 0.21.Observations show that the magnitude difference between the main sequence turn-off point and the ZAHB in a number of well observed globular clusters is independent of [Fe/H], and has a stable value of dV = 3.54 with a disperion of only 0.1 magnitudes. Using this fact, the absolute magnitude of the main sequence turn-off is determined in any given globular cluster from the observed apparent magnitude of the ZAHB by adopting any particular MV(RR) = f([Fe/H]) calibration.Ages of the clusters are shown to vary with [Fe/H] by amounts that depend upon the slopes of the MV(RR) = f([Fe/H]) calibrations. The calibrations show that there would be a steep dependence of the age on [Fe/H] if MV(RR) does not depend on [Fe/H]. No dependence of age on metallicity exists if the RR Lyrae luminosities depend on [Fe/H] as dMV(RR)/d[Fe/H] = 0.37. If Oxygen is not enhanced as [Fe/H] decreases, the absolute average age of the globular cluster system is 16 Gyr, independent of [Fe/H], using the steep MV(RR)/[Fe/H] calibration that is favored. If Oxygen is enhanced by [O/Fe] = – 0.14 [Fe/H] + 0.40 for [Fe/H] < –1.0, as suggested from the observations of field subdwarfs, then the age of the globular cluster system decreases to 13 Gyr, again independent of [Fe/H], if the RR Lyrae ZAHB luminosities have a metallicity dependence of dMV(RR)/d[Fe/H] = 0.37.

scholarly journals Measurement of the absolute luminosity with the ALEPH detector

1992 ◽  
Vol 53 (3) ◽  
pp. 375-390 ◽  
Author(s):  
◽  
D. Decamp ◽  
B. Deschizeaux ◽  
C. Goy ◽  
J. -P. Lees ◽  
...  
Keyword(s):  
Aleph Detector ◽  
The Absolute ◽  
Absolute Luminosity

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 Magnitude and Kinematics of RR Lyrae Stars Via Statistical Parallax

1996 ◽  
Vol 112 ◽  
pp. 2110 ◽  
Author(s):  
Andrew C. Layden ◽  
Robert B. Hanson ◽  
Suzanne L. Hawley ◽  
Arnold R. Klemola ◽  
Christopher J. Hanley
Keyword(s):  
Absolute Magnitude ◽  
Rr Lyrae Stars ◽  
Rr Lyrae ◽  
The Absolute ◽  
Lyrae Stars

scholarly journals New Pulsational Constraints to the Distance of Globular Clusters and the MV(RR)–[Fe/H] Relation

2000 ◽  
Vol 176 ◽  
pp. 263-263
Author(s):  
Vincenzo Ripepi ◽  
Filippina Caputo ◽  
Vittorio Castellani ◽  
Marcella Marconi
Keyword(s):  
Globular Clusters ◽  
Apparent Distance ◽  
Chemical Compositions ◽  
Distance Modulus ◽  
Instability Strip ◽  
Rr Lyrae ◽  
Visual Magnitude ◽  
The Absolute ◽  
Galactic Globular Clusters

AbstractWe applied the pulsational method (Caputo 1997) to derive the distances to a sample of galactic globular clusters with well-observed RR Lyrae populations. To apply the method we calculated a set of pulsational theoretical boundaries of the instability strip for the range of masses and chemical compositions spanned by the analysed clusters. In this way we were able to fix simultaneously the apparent distance modulus and the absolute visual magnitude of the RR Lyrae population of each cluster in the sample. As a result we derived the following relations:

scholarly journals The Absolute Luminosity of RR Lyrae Variables

1988 ◽  
Vol 126 ◽  
pp. 587-588
Author(s):  
C. Cacciari ◽  
G. Clementini ◽  
L. Prevot
Keyword(s):  
Surface Brightness ◽  
Radial Velocities ◽  
Photoelectric Photometry ◽  
Rr Lyrae ◽  
Metal Abundance ◽  
Metal Abundances ◽  
Complete Set ◽  
Effective Temperatures ◽  
Absolute Magnitudes ◽  
Absolute Luminosity

We have taken UBVRI photoelectric photometry and CORAVEL radial velocities for 6 field RR Lyraes, i.e. SW And, YZ Cap, SW Dra, SS For, RV Phe and V440 Sgr, with the purpose of applying the Baade-Wesselink (B-W) method and determining their absolute magnitudes. The present improvements with respect to previous applications of the method are: a) the use of the (V-I) color, which shows the smallest sensitivity to gravity and metal abundance in the color-visual surface brightness plane. b) the use of a new grid of model atmospheres by Buser and Kurucz (1986), which include an improved treatment of opacity and convection. They provide a complete set of models for the relevant values of effective temperatures, gravities and metal abundances, thus avoiding the need of inaccurate interpolations or extrapolations.

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