Spectroscopic study of sigma Geminorum from IUE Virtual Observatory Resource

Authors
  1. Ekmekci F.
  2. Karakus O.
  3. Published by
    CDS
Abstract

The IUE spectra of {sigma} Gem have been taken from the NASA IUE archive using IDL (Interactive Data Language). The spectra have been observed in 1979-1986 period. All the spectra analysed in the present study have NEWSIPS reductions and consist of 25 LWP, 8 LWR and 5 SWP images in high resolution, and 2 LWP and 14 SWP images in low dispersion. The emission lines, identified as activity indicators and originating in the chromosphere and transition region, are seen in the spectra. The emission line fluxes and equivalent widths are computed based on Gaussian profile fitting procedures to examine the existence of any line flux variation that depends on time or orbital phase. It was found that there is a flux variation with time and orbital phase that is in good agreement with the photometric light curve variation. By comparing the flux variation with simultaneous light curve variation, it can be shown that there is a relation between the ultraviolet flux variation and the spot activity of the system, as shown by Ayres et al. (1984ApJ...279..197A) and Engvold et al. (1988A&A...192..234E) based on their IUE (with IUESIPS reduction) spectral analysis. Moreover, it was inferred that there is no ultraviolet excess in {sigma} Gem by comparing the spectra of {beta} Gem taken as a comparison star. The Mg II h and k radial velocity curves of {sigma} Gem were in a good agreement with data obtained by Eker (1986MNRAS.221..947E) and Duemmler et al. (1997A&AS..123..209D).

Keywords
  1. spectroscopic-binary-stars
  2. spectroscopy
  3. ultraviolet-astronomy
  4. line-intensities
Bibliographic source Bibcode
2002A&A...391..641E
See also HTML
https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/391/641
IVOA Identifier IVOID
ivo://CDS.VizieR/J/A+A/391/641
Document Object Identifer DOI
doi:10.26093/cds/vizier.33910641

Access

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http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/391/641
https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/391/641
http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/391/641
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History

2002-09-01T15:43:04Z
Resource record created
2002-09-01T15:43:04Z
Created
2002-09-01T15:43:14Z
Updated

Contact

Name
CDS support team
Postal Address
CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France
E-Mail
cds-question@unistra.fr