Accession Number : ADA114411

Title :   IUE Observations of Hyades Stars,

Corporate Author : STANFORD UNIV CA INST FOR PLASMA RESEARCH

Personal Author(s) : Zolcinski,Marie-Christine S ; Antiochos,Spiro K ; Stern,Robert A ; Walker,Arthur B C

PDF Url : ADA114411

Report Date : Jan 1982

Pagination or Media Count : 36

Abstract : The authors have obtained short wavelength, low dispersion ultraviolet spectra of seven of the brightest X-ray emitting stars in the Hyades cluster with the IUE observatory. Four of the stars show evidence of emission lines characteristic of transition region temperatures (about 30,000 - 2000,000 K): for the remaining three stars, we derive upper limits for emission line fluxes. In addition, observed were three of the above stars with the long wavelength spectrograph on IUE at high dispersion and find evidence for chromospheric emission from the MG II h and k lines for two of these objects. Combining the IUE results with X-ray observations from the survey of the Hyades with the Einstein Observatory. The author estimated the differential emission measure function for each of the above stars. They derived constraints on stellar atmospheric parameters (chromospheric pressure, coronal temperature and filling factor), and discussed the implications of the results for models of stellar chromospheres and coronae.

Descriptors :   *Stellar atmospheres, *Emission spectra, Ultraviolet spectroscopy, Parametric analysis, Spectrum analysis, Chromosphere, X ray spectra, Extrapolation

Subject Categories : Astronomy
      Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE