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Full-Text Articles in Physical Sciences and Mathematics
The Orbit And Pulsation Periods Of The Γ Doradus Variable Hr 6844 (V2502 Ophiuchi), Francis C. Fekel, Gregory W. Henry
The Orbit And Pulsation Periods Of The Γ Doradus Variable Hr 6844 (V2502 Ophiuchi), Francis C. Fekel, Gregory W. Henry
Information Systems and Engineering Management Research Publications
We obtained spectroscopic and photometric observations of the γ Doradus variable HR 6844 (=V2502 Ophiuchi). Radial velocities show that this star is a single-lined binary with a period of 4.4852 days. The primary is an F1 V star, while the secondary is likely an M dwarf. Velocity residuals to a circular orbit have a period of 1.3071 days and an amplitude of ∼3 km s-1. Three periods of light variation were detected, 1.30702, 1.4350, and 0.62286 days. The first period is essentially identical to that found in the radial velocities and has the largest amplitude, a peak-to-peak value of 0.067 …
Spectroscopy Of Early F Stars: Γ Doradus Candidates And Possible Metallic Shell Stars, Francis C. Fekel, Phillip B. Warner, Anthony B. Kaye
Spectroscopy Of Early F Stars: Γ Doradus Candidates And Possible Metallic Shell Stars, Francis C. Fekel, Phillip B. Warner, Anthony B. Kaye
Information Systems and Engineering Management Research Publications
We obtained high-resolution spectroscopic observations of 34 γ Doradus candidates. From the red-wavelength spectra, we determined spectral classes, radial velocities, and projected rotational velocities. The spectra of seven late A or early F stars show metallic lines that have composite profiles consisting of a narrow component near the center of a broad line, indicating that they may be shell stars or binaries. Several stars, including HD 152896, HD 173977, HD 175337, and HD 195068/9, show large line profile asymmetries. Two stars, HD 11443 (=α Trianguli) and HD 149420, are ellipsoidal variables and not γ Doradus stars. The percentage of binary …
A Dozen New Γ Doradus Stars, Gregory W. Henry, Francis C. Fekel
A Dozen New Γ Doradus Stars, Gregory W. Henry, Francis C. Fekel
Information Systems and Engineering Management Research Publications
We use new high-dispersion spectroscopic and precise photometric observations to identify 12 new γ Doradus stars. Two of the 12 systems are double-lined binaries that show obvious velocity variability. Five other stars have metallic lines with composite profiles characterized by a narrow feature near the center of each broad component. Spectrograms of the Hα line indicate that all five stars are binaries rather than shell stars. The remaining five stars in our sample are probably single. All 12 stars are photometrically variable with amplitudes between 6 and 87 mmag in Johnson B and periods between 0.3 and 1.2 days. Four …