Daniel M. Popper
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View article: Orbits of Main-Sequence Eclipsing Binaries of Types Late F to K. IV. HS Aquarii, V1430 Aquilae, HP Aurigae, and CV Bootis
Orbits of Main-Sequence Eclipsing Binaries of Types Late F to K. IV. HS Aquarii, V1430 Aquilae, HP Aurigae, and CV Bootis Open
In this fourth paper of a series, values of M i are obtained for the late F–K eclipsing binaries HS Aqr, V1430 Aql, HP Aur, and CV Boo. The values of M i lie in the range 1.07 to 0.71 solar masses, both extremes being for HS Aqr. Lacking u…
View article: <i>Hipparcos</i>Parallaxes of Eclipsing Binaries and the Radiative Flux Scale
<i>Hipparcos</i>Parallaxes of Eclipsing Binaries and the Radiative Flux Scale Open
Eclipsing binaries with Hipparcos parallaxes are found to define a radiative flux relation for main‐sequence stars in the B6–F0 range about as well as stars with angular diameters and to extend the range to F8. The fluxes of components of …
View article: Orbits of Detached Main-Sequence Eclipsing Binaries of Types Late F to K. III. AD Bootis and DU Leonis
Orbits of Detached Main-Sequence Eclipsing Binaries of Types Late F to K. III. AD Bootis and DU Leonis Open
In this third paper of a series, spectroscopic orbits are obtained for the main-sequence eclipsing binaries AD Boo (P = 2.07 days, F6 + G0) and DU Leo (P = 1.37 days, G0:). The available photometry of AD Boo may be adequate, but a second p…
View article: Procedures for radial velocities of close binaries from spectra obtained with the Lick echelle-CCD spectrometer
Procedures for radial velocities of close binaries from spectra obtained with the Lick echelle-CCD spectrometer Open
Procedures are described for processing the raw data and analyzing them for radial velocities from spectra of close binary stars observed with the CCD-echelle Hamilton spectrometer on the 3-m Shane telescope at the Lick Observatory. IRAF s…
View article: Rediscussion of eclipsing binaries. XVIII - Faint secondaries in the spectra of early B-type systems
Rediscussion of eclipsing binaries. XVIII - Faint secondaries in the spectra of early B-type systems Open
Spectra of 3 early B-type eclipsing binaries, for which velocities of faint secondary components have been reportedly measured on photographic spectrograms, have been observed with high resolution and signal-to-noise ratio. The equipment e…
View article: Preliminary Orbits from Velocities with the CCD-Echelle Spectrometer at Lick
Preliminary Orbits from Velocities with the CCD-Echelle Spectrometer at Lick Open
The Hamilton CCD-echelle spectrometer at the coudé focus of the 3-m Shane telescope of the Lick observatory has been described by Vogt (1987). Illustrations of some binary star spectra obtained with this instrument are given by Popper & Ne…
View article: The Cool Algols
The Cool Algols Open
Five semi-detached systems have been identified having detached components with spectral types G or K. These stars form a sequence having temperature decreasing with increasing mass, in contrast to the “classical” Algols with hotter detach…
View article: Masses, Radii and Luminosities from Analysis of Eclipsing Binaries
Masses, Radii and Luminosities from Analysis of Eclipsing Binaries Open
The reliability of values of the fundamental properties of stars derived from eclipsing binary analysis is discussed in terms of general concepts. Since the principles involved in the determination of masses and radii are simple, the heart…
View article: Lick velocities of the eclipsing binary Chi-2 Hydrae
Lick velocities of the eclipsing binary Chi-2 Hydrae Open
The velocities of the components of the bright late B-type eclipsing binary Chi-2 Hya derived from 19 spectrograms obtained between 1972 and 1979 are presented. They have a scale of 16.2 A/mm and are 1.0 mm wide. Circular elements derived …
View article: Spectrographic material for RS Canum Venaticorum and Algol binaries
Spectrographic material for RS Canum Venaticorum and Algol binaries Open
A synopsis is given of unpublished spectrographic material on 22 subgiant eclipsing binaries with Ca II emission lines and nine semidetached binaries with B- or A-type primaries.
View article: Comments on Reduction of Photoelectric Photometry
Comments on Reduction of Photoelectric Photometry Open
Some critical details in the reduction of photometric observations to a standard system are discussed. Emphasis is on the avoidance of small systematic errors.
View article: The double-lined spectroscopic binary HD 214686
The double-lined spectroscopic binary HD 214686 Open
Orbital elements for the 6th-magnitude 21.7-day double-lined binary HD 214686 are determined from coude spectrograms. Photometric observations show the system to contain two F7 V stars, and minimum masses near 1.16 solar masses are found f…
View article: Improved orbits of the visual binary del Equ.
Improved orbits of the visual binary del Equ. Open
Additional coude' spectrograms of Equ combined with analysis of the available visual double star observations allow us to determine the properties of this F7 V system with high precision. The average values of the mass and visual absolute …
View article: The masses of cool supergiants : the interacting eclipsing system AZ Cas.
The masses of cool supergiants : the interacting eclipsing system AZ Cas. Open
Data are presented from 63 spectrograms covering two cycles of the nine-year eclipsing system AZ Cas. The orbital elements are derived and it is seen that mass is lost from the M supergiant primary at periastron passage in an eccentric (e …
View article: Star Spots on AR Lac Type Stars
Star Spots on AR Lac Type Stars Open
There is no generally accepted definition of AR Lac Stars, and the term RS CVn stars is used interchangeably or to refer to a particular subgroup. For the purposes of this discussion I use the term AR Lac stars to refer to detached close b…
View article: DL Virginis - an Eclipsing Binary as Part of a Triple System
DL Virginis - an Eclipsing Binary as Part of a Triple System Open
The A-type eclipsing binary, DL Vir, period 1d3 shares a common center of mass with a G8 giant, their period being in the vicinity of 2500d, with a large uncertainty. The eclipsing companion is not visible in the spectrum, although the dis…
View article: The Mass and Absolute Magnitude of the Visual Binary Delta Equulei from Radial Velocity Observations
The Mass and Absolute Magnitude of the Visual Binary Delta Equulei from Radial Velocity Observations Open
We have determined that the average component of 8 ISqu has a mass 9)? = 1.23 I 0.089)? , and an absolute magnitude Mv = + 4.0 I 0.1. This determination is based on new observations of the system as a spectroscopic binary combined with dat…
View article: Physical Data from Normal Binaries
Physical Data from Normal Binaries Open
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View article: Survey of Spectra of Southern Eclipsing Binaries.
Survey of Spectra of Southern Eclipsing Binaries. Open
In the months of December 1964 to June 1965 a survey of spectra of southern eclipsing binaries was carried out at the Mount Stromlo Observatory. The grating dispersion was 22 A/mm. Table I summarizes the results obtained from inspection of…
View article: Masses of the Components of Zeta Aurigae.
Masses of the Components of Zeta Aurigae. Open
The masses of the components of the well-known eclipsing system, Zeta Aurigae are re- investigated by means of new spectrographic material obtained expressly for the purpose. The critical quantity needed is the amplitude of velocity variat…
View article: Notes on Eclipsing Binaries
Notes on Eclipsing Binaries Open
The observations reported here were obtained in the course of a program of searching for eclipsing binaries which may increase our meager knowledge of the fundamental properties of stars not on the main sequence. Of the stars discussed, th…
View article: Two eclipsing binaries with giant components.
Two eclipsing binaries with giant components. Open
TW Cancri. An earlier report1 on this 70-day eclipsing binary indicated that the brighter and hotter component receded after primary minimum, which is a total eclipse. It is now clear that the lines measured are instead those of the cooler…
View article: From Field and Study
From Field and Study Open
Note on Scopoli.-Reading the article hy Todd on White-fronted Geese (Condor 52, 1950:63-68)) I was shghtly startled by the reference to Scopoli as an Italian.Perhaps the underlying reason was that I have usually seen his name as Johann Ant…