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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Hd 71636, A Newly Discovered Eclipsing Binary, Gregory W. Henry, Francis C. Fekel, James R. Sowell, Joel S. Gearhart
Hd 71636, A Newly Discovered Eclipsing Binary, Gregory W. Henry, Francis C. Fekel, James R. Sowell, Joel S. Gearhart
Information Systems and Engineering Management Research Publications
Our differential BV photometric observations, acquired with an automated telescope at Fairborn Observatory, show that HD 71636 is an eclipsing binary. From follow-up red-wavelength spectroscopic observations we classify the primary and secondary as an F2 dwarf and an F5 dwarf, respectively. The system has a period of 5.01329 days and a circular orbit. We used the Wilson-Devinney program to simultaneously solve our BV light curves and radial velocities and determined a number of fundamental properties of the system. Comparison with evolutionary tracks indicates that both stars are well ensconced on the main sequence. The age of the system is about …
Hd 131861, A Double-Line Spectroscopic Triple System, Francis C. Fekel, Gregory W. Henry, David J. Barlow, Dimitri Pourbaix
Hd 131861, A Double-Line Spectroscopic Triple System, Francis C. Fekel, Gregory W. Henry, David J. Barlow, Dimitri Pourbaix
Information Systems and Engineering Management Research Publications
Our red-wavelength spectroscopic observations of HD 131861, a previously known single-line multiple system, span 20 years. Now lines of two components, the short-period F5 V primary and G8 V secondary, have been detected. The inner orbit is circular with a period of 3.5507439 days, while the outer orbit of the system has a period of 1642 days or 4.496 yr and a relatively low eccentricity of 0.10. Analysis of the Hipparcos data produces a well-determined astrometric orbit for the long-period system that has an inclination of 52°. Our photometric observations show shallow primary and secondary eclipses of the short-period pair, …
Hr 1613: A Slowly Rotating A Dwarf Spectroscopic Binary With Solar Abundances, Francis C. Fekel, Michael H. Williamson, Christiane Buggs, Gerald Onuoha, Brittany Smith
Hr 1613: A Slowly Rotating A Dwarf Spectroscopic Binary With Solar Abundances, Francis C. Fekel, Michael H. Williamson, Christiane Buggs, Gerald Onuoha, Brittany Smith
Information Systems and Engineering Management Research Publications
From two sets of radial velocities we have obtained the orbital elements of HR 1613. This single-lined binary has an orbital period of 8.11128 days and a nearly circular orbit. The primary has an A9 V spectral type and a v sin i value of 11 km s-1, while the unseen secondary is likely a K or M dwarf. Spectral classifications and spectrum synthesis analysis indicate that the abundances of the primary are normal. We reject the possibility that the primary of HR 1613 is seen nearly pole-on and instead argue that its rotational inclination is at least 20°, resulting …
New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. I. Rr Lyncis, 12 Bootis, And Hr 6169, Jocelyn Tomkin, Francis C. Fekel
New Precision Orbits Of Bright Double-Lined Spectroscopic Binaries. I. Rr Lyncis, 12 Bootis, And Hr 6169, Jocelyn Tomkin, Francis C. Fekel
Information Systems and Engineering Management Research Publications
Radial velocities from the 2.1 m telescope at McDonald Observatory supplemented with radial velocities from the coudé feed telescope at Kitt Peak National Observatory provide new precise orbits for the double-lined spectroscopic binaries RR Lyn (A3/A8/A6), 12 Boo (F8 IV), and HR 6169 (A2 V). We derive orbital dimensions (a1 sin i and a2 sin i) and minimum masses (m1 i and m2 i) with accuracies of 0.06%-0.9%. The three systems, which have V magnitudes of 5.53, 4.82, and 6.42, respectively, are all sufficiently bright that they are easily within the grasp of modern optical interferometers and so afford the …
The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models For Active And Inactive Solar-Type Stars, Guillermo Torres, Claud H. Sandberg Lacy, Laurence A. Marschall, Holly A. Sheets, Jeff A. Mader
The Eclipsing Binary V1061 Cygni: Confronting Stellar Evolution Models For Active And Inactive Solar-Type Stars, Guillermo Torres, Claud H. Sandberg Lacy, Laurence A. Marschall, Holly A. Sheets, Jeff A. Mader
Physics and Astronomy Faculty Publications
We present spectroscopic and photometric observations of the chromospherically active (X-ray strong) eclipsing binary V1061 Cyg (P = 2.35 days) showing that it is in reality a hierarchical triple system. We combine these observations with Hipparcos intermediate data (abscissa residuals) to derive the outer orbit with a period of 15.8 yr. We determine accurate values for the masses, radii, and effective temperatures of the eclipsing binary components, as well as for the mass and temperature of the third star. For the primary we obtain M = 1.282 ± 0.015 M⊙, R = 1.615 ± 0.017 R⊙, Teff = 6180 ± …
Spectroscopy And Photometry Of The Double-Lined Binary Hd 149420, Francis C. Fekel, Gregory W. Henry
Spectroscopy And Photometry Of The Double-Lined Binary Hd 149420, Francis C. Fekel, Gregory W. Henry
Information Systems and Engineering Management Research Publications
We have used new spectroscopic and photometric observations of HD 149420 to obtain an improved orbital element solution and determine some basic properties of the system. This double-lined binary has an orbital period of 3.39430 days, a circular orbit, and a mass ratio of 0.52. The primary is somewhat evolved, with an A9 IV spectral type, while the secondary is estimated to be an F5: dwarf. The secondary may be synchronously rotating, but the primary is rotating substantially slower than its synchronous velocity. Our photometric observations confirm the light variability and period found by Hipparcos. We determine a photometric period …