The chromospheres of classical Cepheids. I - Low resolution IUE spectra
Abstract
A program to study the behavior of chromospheres in classical Cepheids using both ground-based and satellite-based observations. Five stars, delta Cep, nu Aql, beta Dor, zeta Gem, and l Car, have been included, and where possible the various types of data have been obtained simultaneously. The first part of this investigation concerns low dispersion spectra from the IUE satellite. Fine error sensor (FES) magnitudes are presented for the five Cepheids and, in the case of one, nu Aql, are used to rediscuss the period. The 'artificial viscosity dip' predicted by some theoretical calculations may be present in the FES light curve of delta Cep. The low dispersion spectra have been used to determine continuum magnitudes at various UV wavelengths, and light curves are shown. The amplitude increases with decreasing wavelength except around 1550 A. Line emission in the short wavelength region is observed in three of the Cepheids and is found to be phase dependent. Some correspondence is found between the variation of the emission lines and the appearance of bumps on the UV light curves.
- Publication:
-
The Astrophysical Journal Supplement Series
- Pub Date:
- February 1982
- DOI:
- 10.1086/190774
- Bibcode:
- 1982ApJS...48..185S
- Keywords:
-
- Cepheid Variables;
- Chromosphere;
- Stellar Spectra;
- Ultraviolet Astronomy;
- Ultraviolet Spectra;
- Emission Spectra;
- Iue;
- Light Curve;
- Line Spectra;
- Radiant Flux Density;
- Satellite-Borne Instruments;
- Space Observations (From Earth);
- Spectral Resolution;
- Star Distribution;
- Astrophysics