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University of Southern California


Faculty
 
Dr. Geraldine Peters

Research Professor
Building: SHS 271
Mail Code: 1341
Department: Space Sciences Center
Division: LAS
Telephone: (213) 740-6336
Fax: (213) 740-6342
Email: gipeters@mucen.usc.edu
URL: N/A
Updated: June 8, 2007



Dr. Peters

(from  Bulletin of the American Astronomical Society, 33, 547, 2001.)

            G. J. Peters continued her study of short-term wind and photospheri activity in Be stars in collaboration with D. Gies (Georgia State Univ.).  A cross-correlation technique has been used to extract information on the nature of the photospheric line profile variability seen during 12 multiwavelength campaigns involving the  IUE spacecraft.  Peters also continued her investigation of the long-term, apparent yearly, cyclical variability in the winds of 8 Eri and 66 Oph during the lifetime of the IUE. G. Peters began a study of the short-term micro-emission activity in the Be star B Aqr that lost its emission-line disk in the mid-1990s. Peters continued to serve as Editor-in-Chief of the  Be Star Newsletter, a periodical published for the Working Group on Active B Stars of the IAU Divisions IV (Stars) and V (Variable Stars)  in both paper (D. R. Gies, Georgia State University, technical editor) and electronic (http://www.limber.org/benews/, D. McDavid, technical editor) editions.

            G. J. Peters continued to investigate the circumstellar material in Algol binary systems.  Attention was directed toward the systems that contain early B primaries, especially those in which the gas stream strikes the mass gainer's photosphere tangentially or impacts at a shallow angle.  It was found that the azimuthal distribution of the high temperature plasma (HTAR)and the amount and nature of the mass flow away from the system near phase 0.5 depend on the impact angle.  Peters collaborated with R. Polidan (GSFC) and D. E. Lynch (Global Science & Tech.)in a study of apparent bipolar flows in V356 Sgr  & TT Hya. They began an analysis of a series of spectra of V356 Sgr obtained with the FUSE spacecraft throughout the total eclipse of the primary.  A high temperature plasma (~300,000 K) is inferred from the O VI emission feature that dominates the spectrum.  Peters presented a review talk on Algol binaries at the meeting ``The Influence of Binaries on Stellar Population Studies'' held in Brussels, Belgium, 21--25 August 2000.

            G. J. Peters and J. Grigsby (Ball Aerospace) continued a study of the abundances of the Fe group elements in AV 304, a sharp-lined B0.5V star in the Small Magellanic Cloud, using spectra from HST/STIS.  The abundances ranged from 0.5-1.0 dex below those observed in the sun.  Peters & Grigsby also completed an investigation of the abundances of the Fe group elements in the ultrasharp-lined early B star  4 Her using coadded high resolution IUE data, the Kurucz SYNTHE code, and Kurucz model atmospheres.

 
 
    website last updated 5/31/2007