Výsledky vyhledávání - "D. H. McNamara"

Autor: D. H. McNamara

Publikováno v: Publications of the Astronomical Society of the Pacific. 113:335-343

We examine the luminosity levels of the main-sequence turnoffs, , and horizontal branches, Mv(HB), in 16 globular clusters. An entirely new approach of inferring the luminosity levels by utilizing high-amplitude δ Scuti variables (HADS) is introduce

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2dba631a01b3d087114fae2fa1dcd3ab
https://doi.org/10.1086/319332

Zobrazit plný text záznamu

The Identification of Pulsation Modes of High‐Amplitude δ Scuti Stars in ω Centauri and the Carina Galaxy

Autor: D. H. Mcnamara

Publikováno v: Publications of the Astronomical Society of the Pacific. 112:1096-1102

We analyze photometric observations of high-amplitude d Scuti stars (HADS) in the globu- lar cluster u Cen and the Carina galaxy. The pulsation modes of the HADS are inferred primarily from their positions in V ,l ogP diagrams. For u Cen we identify

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::2e7aa2f2d18ac82f95f7065237fe24fc
https://doi.org/10.1086/316605

Zobrazit plný text záznamu

The Distance to the Galactic Center

Autor: D. H. McNamara, J. B. Madsen, B. F. Ericksen, J. Barnes

Publikováno v: International Astronomical Union Colloquium. 176:208-211

The Optical Gravitational Lensing Experiment (OGLE) data on high-amplitude d Scuti stars (HADS) and RR Lyrae stars have been analyzed to determine the distance to the Galactic bulge. Individual color excesses and V absorption for each individual vari

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::815370ca2089c12d854b6bc76d9d1029
https://doi.org/10.1017/s0252921100057559

Zobrazit plný text záznamu

The Slope of the RR Lyrae Variables \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $M_{v},f$ \end{document} [Fe/H] Relation

Autor: D. H. McNamara

Publikováno v: Publications of the Astronomical Society of the Pacific. 111:489-493

We discuss the slope of the RR Lyrae variables Mv,[Fe/H] relation by two independent methods. We show that the slope is 0.32 if Baade-Wesselink Mv values are used only for stars with [Fe/H] > -1.5. Because the metal abundances of the variables are co

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::dbe19661163021598c1f128f04edadc6
https://doi.org/10.1086/316352

Zobrazit plný text záznamu

Interesting Properties of Delta Scuti Stars

Autor: D. H. McNamara, Joyce Ann Guzik, Paul A. Bradley

Publikováno v: AIP Conference Proceedings.

We describe the ages of δ Scuti stars as a function of the fundamental period of pulsation. We show that the metal‐poor variables (pulsating blue stragglers or SX Phe stars) should be restricted to short periods as observed. The metal‐strong var

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::08483a67bde9d0bb290154b6e1645570
https://doi.org/10.1063/1.3246531

Zobrazit plný text záznamu

A delta Scuti distance to the Large Magellanic Cloud

Autor: D. H. McNamara, Marcella Marconi, Gisella Clementini

We present results from a well studied delta Scuti star discovered in the LMC. The absolute magnitude of the variable was determined from the PL relation for Galactic delta Scuti stars and from the theoretical modeling of the observed B,V,I light cur

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c2a15e110ea3e81e7249b15a39c53e6e

Zobrazit plný text záznamu

THE RR LYRAE STARS: NEW PERSPECTIVES

Autor: J. Barnes, D. H. McNamara

Publikováno v: The Astronomical Journal. 147:31

We demonstrate that the Oosterhoff II (Oo?II) RR Lyrae ab variables are hotter by ~270?K, at the same period, than Oo?I variables. Or, at the same (B ? V)0 value the Oo?II variables have larger radii than Oo?I variables. This accounts for the reason

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::7c92fbb9e2f57679c17dc762fbd88daa
https://doi.org/10.1088/0004-6256/147/2/31

Zobrazit plný text záznamu

The Luminosities of δ Scuti Stars

Autor: D. H. McNamara

Publikováno v: International Astronomical Union Colloquium. 185:116-117

The δ Scuti stars are variables found in the instability strip above the zero-age main sequence. Radial and nonradial pulsation modes have been detected in these stars. The large-amplitude variables with asymmetric light curves are radial pulsators.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::1da54a8542f3fa16e6bfb2b96641d34f
https://doi.org/10.1017/s0252921100015712

Zobrazit plný text záznamu

DELTA SCUTI, SX PHOENICIS, AND RR LYRAE STARS IN GALAXIES AND GLOBULAR CLUSTERS

Autor: D. H. McNamara

Publikováno v: The Astronomical Journal. 142:110

The distances to four galaxies and two globular clusters which are derived with the aid of period-luminosity and period-color relations of δ Scuti and SX Phe stars are compared to the distances derived by other methods, in particular RR Lyrae stars.

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::1f982dba1776c48099fdf48da5f2a83a
https://doi.org/10.1088/0004-6256/142/4/110

Zobrazit plný text záznamu

A Theoretical Period-Luminosity Relation of Dwarf Cepheids

Autor: John M. Powell, D. H. McNamara

Publikováno v: International Astronomical Union Colloquium. 138:437-438

Dwarf Cepheids (large-amplitude δ Sct variables and SXPhe variables in the GCVS) are late A-type stars near light maximum and early-F stars near light minimum. In the lower part of the instability strip where these stars are found the pulsation cons

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::445ff28c4aa4dcf7fe05cca8e0f64119
https://doi.org/10.1017/s025292110002087x

Zobrazit plný text záznamu

Vyhledávací nástroje:

Upřesnit hledání