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Full-Text Articles in Physical Sciences and Mathematics
Chromospherically Active Stars. Xxvi. The Double-Lined Late-Type Binary Hd 19485 = Wz Arietis, Francis C. Fekel, Charles Thomas Bolton
Chromospherically Active Stars. Xxvi. The Double-Lined Late-Type Binary Hd 19485 = Wz Arietis, Francis C. Fekel, Charles Thomas Bolton
Information Systems and Engineering Management Research Publications
We have used spectroscopic observations to determine the orbital elements and some basic properties of the double-lined spectroscopic binary HD 19485 = WZ Ari. The orbital period is 6.247854 days, and the orbit is circular. The G5 V primary and K0 V secondary are chromospherically active. One star or possibly both are synchronously rotating. Based on the Hipparcos parallax and the magnitude differences derived in this work, we find that both components are approximately 1 mag above the zero-age main sequence, a result that is inconsistent with the assumption that the components are coeval. We discuss some possible solutions to …
Patterns Of Photometric And Chromospheric Variation Among Sun-Like Stars: A 20 Year Perspective, G. Wesley Lockwood, Brian A. Skiff, Gregory W. Henry, Stephen M. Henry, Richard R. Radick, Sallie L. Baliunas, Robert A. Donahue, Willie Soon
Patterns Of Photometric And Chromospheric Variation Among Sun-Like Stars: A 20 Year Perspective, G. Wesley Lockwood, Brian A. Skiff, Gregory W. Henry, Stephen M. Henry, Richard R. Radick, Sallie L. Baliunas, Robert A. Donahue, Willie Soon
Information Systems and Engineering Management Research Publications
We examine patterns of variation of 32 primarily main-sequence Sun-like stars [selected at project onset as stars on or near the main sequence and color index 0.42 ≤ (B - V) ≤ 1.4], extending our previous 7-12 yr time series to 13-20 yr by combining Strömgren b, y photometry from Lowell Observatory with similar data from Fairborn Observatory. Parallel chromospheric Ca II H and K emission data from the Mount Wilson Observatory span the entire interval. The extended data strengthen the relationship between chromospheric and brightness variability at visible wavelengths derived previously. We show that the full range of photometric …
Photospheric And Chromospheric Active Regions In Four Young Solar-Type Stars, Katia Biazzo, Antonio Frasca, Gregory W. Henry, S. Catalano, E. Marilli
Photospheric And Chromospheric Active Regions In Four Young Solar-Type Stars, Katia Biazzo, Antonio Frasca, Gregory W. Henry, S. Catalano, E. Marilli
Information Systems and Engineering Management Research Publications
We present a photometric and spectroscopic study of four G-K dwarfs, namely HD 166, epsilon Eri, χ1 Ori, and κ1 Cet. In three cases, we find a clear spatial association between photospheric and chromospheric active regions. For χ1 Ori we do not find appreciable variations of photospheric temperature or chromospheric Hα emission. We applied a spot/plage model to the observed rotational modulation of temperature and flux to derive spot/plage parameters and to reconstruct a rough "three-dimensional" map of the outer atmosphere of κ1 Cet, HD 166, and epsilon Eri.
Infrared Spectroscopy Of Symbiotic Stars. V. First Orbits For Three S-Type Systems: Henize 2-173, Cl Scorpii, And As 270, Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Peter R. Wood, Thomas Lebzelter
Infrared Spectroscopy Of Symbiotic Stars. V. First Orbits For Three S-Type Systems: Henize 2-173, Cl Scorpii, And As 270, Francis C. Fekel, Kenneth H. Hinkle, Richard R. Joyce, Peter R. Wood, Thomas Lebzelter
Information Systems and Engineering Management Research Publications
Infrared radial velocities have been used to compute first orbits of the M giants in three southern S-type symbiotic systems. Of the three, Hen 2-173 has the longest orbital period, 911 days, and also has a noncircular orbit with an eccentricity of 0.21. The large value of its mass function suggests that Hen 2-173 may be an eclipsing system. For CL Sco our spectroscopic orbital period of 626 days is essentially identical to the previously determined light variability period of 625 days, and we have adopted the latter. AS 270 has an orbital period of similar length, 671 days, and …