Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (46) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (4)
· Also-Read Articles (Reads History)
· Translate This Page
Magnetic activity variations of epsilon Eridani
Gray, David F.; Baliunas, Sallie L.
AA(University of Western Ontario, London, Ontario, Canada), AB(University of Western Ontario, London, Ontario, Canada)
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 441, no. 1, p. 436-442 (ApJ Homepage)
Publication Date:
NASA/STI Keywords:
K Stars, Magnetic Variations, Periodic Variations, Solar Granulation, Stellar Magnetic Fields, Stellar Rotation, Stellar Temperature, Astronomical Photometry, Astronomical Spectroscopy, Calcium, H Lines, K Lines, Spectral Emission
Bibliographic Code:


The variations in magnetic activity, temperature and granulation of epsilon Eri (HR 1084, HD 22049, K2 V, B-V = 0.88) in the interval from 1986 to 1992 are discussed in this paper. We monitored the magnetic activity with the Ca II H and K-line emission, the temperature with the ratio of depths of two spectral lines, and the granulation with spectral-line asymmetries. Rotational modulation is seen only in the H and K emission, and it shows a period of 11.10 +/- 0.03 days, in agreement with earlier published values. The star has one dominant activity longitude. The magnetic activity of epsilon Eri is strong and shows irregular excursions that may be superposed on a cyclic variation having a period approximately equal to 5 yr. During the 1986-1992 interval the magnetic activity went through a broad relative minimum. Temperature and granulation changes mimic the variation in H and K emission, with excursions approximately equal to 15 K and approximately equal to 35 m/s, repectively. No long-term photometric observations are available for epsilon Eri, but we calculate a 1.2% variation in luminosity and 0.014 mag in V to have occurred, assuming the radius of the star is constant.

Printing Options

Print whole paper
Print Page(s) through

Return 600 dpi PDF to Acrobat/Browser. Different resolutions (200 or 600 dpi), formats (Postscript, PDF, etc), page sizes (US Letter, European A4, etc), and compression (gzip,compress,none) can be set through the Printing Preferences

More Article Retrieval Options

HELP for Article Retrieval

Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)

Find Similar Abstracts:

Use: Authors
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
arXiv e-prints