Abstract We observed the late-type stars Capella, σ 2 CrB, λ And, AD Leo, GL494, GL569 and Procyon with different combinations of three instruments aboard EXOSAT : the low-energy channel multiplier array (LE), the medium-energy proportional counters (ME), and the transmission grating spectrometer (TGS). We derive crude temperature information on the coronae of these stars from the photometric data, using one- and two-temperature models of optically thin, thermal plasmas. We compare the results with 2-T fits and differential emission measure analyses of three grating observations and with simulations for mixtures of two plasma components with varying emission measure ratios. But for Procyon, all sources have a strong, hot component between 10 and 25 MK. The TGS spectra of Capella and σ 2 CrB reveal a cooler component with comparable emission measure around 5 MK. The emission from the corona of Procyon is dominated by a very cool (0.6 MK) component, with an additional contribution from a 2–3 MK component.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Temperatures of coronae of cool stars, derived from EXOSAT observations


    Contributors:
    Mewe, R. (author) / Lemen, J.R. (author) / Schrijver, C.J. (author)

    Published in:

    Advances in Space Research ; 10 , 2 ; 129-133


    Publication date :

    1989-01-01


    Size :

    5 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English





    Einstein and EXOSAT observations of Geminga revisited

    Mereghetti, S. / Caraveo, P. / Bignami, G.F. | Elsevier | 1993


    Einstein and EXOSAT Observations of Geminga Revisited

    Mereghetti, S. / Caraveo, P. / Bignami, G. F. et al. | British Library Conference Proceedings | 1993


    Einstein and EXOSAT Observations of Geminga Revisited

    Mereghetti, S. | Online Contents | 1993