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Stars, Interstellar Medium and the Galaxy
Information Systems and Engineering Management Research Publications
- Keyword
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- Stellar activity (3)
- Spectroscopic binaries (2)
- Stellar rotation (2)
- Astronomical observatories (1)
- Astronomical spectroscopy (1)
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- Astronomy (1)
- Astrophysics (1)
- Binary stars (1)
- Charge coupled devices (1)
- Chromosphere (1)
- Circumstellar matter (1)
- Close binaries (1)
- Computer programs (1)
- Dwarf stars (1)
- Eccentric orbits (1)
- Eclipsing binary stars (1)
- HD 30957 (1)
- HD 98800 (1)
- HR 7275 (1)
- HR6469=V819 (1)
- Infrared stars (1)
- Late-type stars (1)
- Light (visible radiation) (1)
- Line spectra (1)
- Luminosity (1)
- Orbital elements (1)
- Photometry (1)
- Pre-main-sequence stars (1)
- Precision (1)
- Radial velocity (1)
Articles 1 - 5 of 5
Full-Text Articles in Physical Sciences and Mathematics
Chromospherically Active Stars. Xiii. Hd 30957: A Double Lined K Dwarf Binary, Francis C. Fekel, Virgiljus Dadonas, Julius Sperauskas, Todd R. Vaccaro, L. Ronald Patterson
Chromospherically Active Stars. Xiii. Hd 30957: A Double Lined K Dwarf Binary, Francis C. Fekel, Virgiljus Dadonas, Julius Sperauskas, Todd R. Vaccaro, L. Ronald Patterson
Information Systems and Engineering Management Research Publications
HD 30957 is a double-lined spectroscopic binary with a period of 44.395 days and a modest eccentricity of 0.09. The spectral types of the components are K2-3 V and K5 V. The measured v sin i for both components is less than or equal to 3 km/s and the orbital inclination is estimated to be 69 deg. The system is relatively nearby with a parallax of 0.025 sec or a distance of 40 pc. Space motions of the system indicate that it does not belong to any of the known moving groups. Absolute surface fluxes of the Ca II H …
Chromospherically Active Stars. Xii. Ads 11060 C: A Double Linked K Dwarf Binary In A Quintuple System, Francis C. Fekel, Gregory W. Henry, Melissa L. Hampton, Robert E. Fried, Mary D. Morton
Chromospherically Active Stars. Xii. Ads 11060 C: A Double Linked K Dwarf Binary In A Quintuple System, Francis C. Fekel, Gregory W. Henry, Melissa L. Hampton, Robert E. Fried, Mary D. Morton
Information Systems and Engineering Management Research Publications
ADS 11060 C is a double lined spectroscopic binary with a period of 25.7631 days and an eccentricity of 0.565. Spectral types of the two stars are estimated as K7 V and MO V with a magnitude difference of about 0.55 mag in V. The stars appear to be somewhat metal rich with respect to the Sun. Despite the relatively large masses of 0.53 and 0.51 solar mass, our photometric observations find no evidence for eclipses and we estimate an inclination of 77 deg plus or minus 11 deg. ADS 11060 C is, however, photometrically variable with a period of …
Optical Variability In The Unusual K5 V Infrared-Excess Star Hd 98800, Gregory W. Henry, Douglas S. Hall
Optical Variability In The Unusual K5 V Infrared-Excess Star Hd 98800, Gregory W. Henry, Douglas S. Hall
Information Systems and Engineering Management Research Publications
The dusty infrared-excess star HD 98800 (K5 V) was observed for several weeks in the spring of 1993 by the Vanderbilt/Tennessee State 0.4 m automatic photoelectric telescope. It was found to be a variable star with an amplitude of 0.07 mag in V and a period of 14.7 days. We show, by comparison with other chromospherically active variable stars and constant stars with good observational histories, that the Rossby number for HD 98800, determined to be 0.30, places it well within the regime of stars whose convective envelopes and rotation rates combine to drive a magnetic dynamo strong enough to …
The Spectroscopic-Speckle Triple System Hr 6469, Colin D. Scarfe, David J. Barlow, Francis C. Fekel, Richard F. Rees, R. W. Lyons, Charles Thomas Bolton, Harold A. Mcalister, William I. Hartkopf
The Spectroscopic-Speckle Triple System Hr 6469, Colin D. Scarfe, David J. Barlow, Francis C. Fekel, Richard F. Rees, R. W. Lyons, Charles Thomas Bolton, Harold A. Mcalister, William I. Hartkopf
Information Systems and Engineering Management Research Publications
HR 6469 consists of an evolved G star and a close pair of stars, believed to be on the main sequence, the brighter of which is an early F star. Shallow eclipses have been detected in the close pair and the components of the wide system have been resolved over most of the orbit by speckle interferometry (McAlister & Hartkopf, Second Catalog of Interferometric Observations of Binary Stars, Center for High Angular Resolution Astronomy, Contribution No. 2 (CHARA), 1988). This paper presents radial velocities, obtained at the David Dunlap, McDonald, Kitt Peak and Dominion Astrophysical Observatories, for the G star …
Time-Series Photometric Spot Modeling. Ii. Fifteen Years Of Photometry Of The Bright Rs Cvn Binary Hr 7275., Klaus G. Strassmeier, Douglas S. Hall, Gregory W. Henry
Time-Series Photometric Spot Modeling. Ii. Fifteen Years Of Photometry Of The Bright Rs Cvn Binary Hr 7275., Klaus G. Strassmeier, Douglas S. Hall, Gregory W. Henry
Information Systems and Engineering Management Research Publications
We present a time-dependent spot modeling analysis of 15 consecutive years of V-band photometry of the long-period (Porb = 28.6 days) RS CVn binary HR 7275. This baseline in time is one of the longest, uninterrupted intervals a spotted star has been observed. The spot modeling analysis yields a total of 20 different spots throughout the time span of our observations. The distribution of the observed spot migration rates is consistent with solar-type differential rotation and suggests a lower limit of the differential-rotation coefficient of 0.022 +/-0.004. The observed, maximum lifetime of a single spot (or spot group) is 4.5 …