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Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

1992

Stellar spectra

Articles 1 - 2 of 2

Full-Text Articles in Physical Sciences and Mathematics

Line Profile Asymmetries In Chromospherically Active Stars, Robert C. Dempsey, Bernard W. Bopp, Klaus G. Strassmeier, Arno F. Granados, Gregory W. Henry, Douglas S. Hall Jun 1992

Line Profile Asymmetries In Chromospherically Active Stars, Robert C. Dempsey, Bernard W. Bopp, Klaus G. Strassmeier, Arno F. Granados, Gregory W. Henry, Douglas S. Hall

Information Systems and Engineering Management Research Publications

A powerful, new probe of chromospheric activity, cross-correlation, has been developed and applied to a variety of stars. In this particular application, an entire CCD spectrum of an active star is correlated with the spectrum of a narrow-line, inactive star of similar spectral type and luminosity class. Using a number of strong lines in this manner enables the detection of absorption profile asymmetries at moderate resolution (lambda/Delta lambda about 40,000) and S/N 150:1. This technique has been applied to 14 systems mostly RS CVn's, with 10 not greater than nu sin i not greater than 50 km/s and P not …


Speckle And Spectroscopic Orbits Of The Early A-Type Triple System In Virginis, William I. Hartkopf, Harold A. Mcalister, Xinxing Yang, Francis C. Fekel Jun 1992

Speckle And Spectroscopic Orbits Of The Early A-Type Triple System In Virginis, William I. Hartkopf, Harold A. Mcalister, Xinxing Yang, Francis C. Fekel

Information Systems and Engineering Management Research Publications

Eta Virginis is a bright (V = 3.89) triple system of composite spectral type A2 IV that has been observed for over a dozen years with both spectroscopy and speckle interferometry. Analysis of the speckle observations results in a long period of 13.1 yr. This period is also detected in residuals from the spectroscopic observations of the 71.7919 day short-period orbit. Elements of the long-period orbit were determined separately using the observations of both techniques. The more accurate elements from the speckle solution have been assumed in a simultaneous spectroscopic determination of the short- and long-period orbital elements. The magnitude …