Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Astrophysics and Astronomy
Chromospherically Active Stars. Ix. Hd 33798 = V390 Aurigae: A Lithium-Rich Rapidly Rotating Single Giant., Francis C. Fekel, Laurence A. Marschall
Chromospherically Active Stars. Ix. Hd 33798 = V390 Aurigae: A Lithium-Rich Rapidly Rotating Single Giant., Francis C. Fekel, Laurence A. Marschall
Information Systems and Engineering Management Research Publications
Results are presented of spectroscopic observations of HD 33798 obtained to determine if this star is a short-period binary and to examine its evolutionary status. Analysis of 40 radial velocities indicates no periodic velocity variations, suggesting that the star is single, so its rapid rotation is highly unusual. This rotation is inconsistent with the rotational brake hypothesis advanced by Gray (1989). It is proposed that HD 33798 is in a post-main-sequence phase of evolution. Its space motion is similar to FK Com, suggesting that it is a coalesced binary in the process of spinning down. Scenarios are presented to explain …
The Extraordinary 1989 December 14/15 Optical Flare Events On V711 Tauri, Gregory W. Henry, Douglas S. Hall
The Extraordinary 1989 December 14/15 Optical Flare Events On V711 Tauri, Gregory W. Henry, Douglas S. Hall
Information Systems and Engineering Management Research Publications
Photometry in B and V taken with the Vanderbilt Tennessee State 16 inch (41 cm) robotic telescope confirms the intense broad-band optical continuum flare activity reported by Chinese observers on the active chromosphere binary V711 Tau on December 14/15, 1989. Twelve hours after the flare reported from China, there occurred a separate and more intense flare with B and V amplitudes of 0.69 and 0.42 mag, respectively. These amplitudes correspond to peak flare luminosities of approximately 2 x 10 to the 33rd ergs/s in B and 1 x 10 to the 33rd ergs/s in V. The observed color of its …
Chromospherically Active Stars. Viii. Hd 155683 = V972 Herculis: Observational Constraints On Evolutionary Theory, Francis C. Fekel
Chromospherically Active Stars. Viii. Hd 155683 = V972 Herculis: Observational Constraints On Evolutionary Theory, Francis C. Fekel
Information Systems and Engineering Management Research Publications
V792 Her is an eclipsing RS CVn binary with an orbital period of 27.54 days whose components have spectral types of K0 III and F2 IV. New spectroscopic observations combined with existing photometry have resulted in masses of 1.47 + or - 0.003 solar mass and 1.41 + or - 0.003 solar mass for the K giant and F star, respectively. Additional fundamental parameters are derived. Standard evolutionary models were specifically computed by VandenBerg (1990) for the two stars. The best fit occurs if the components are somewhat metal poor with Fe/H/ = - 0.46. Ages of about 2.3 x …