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 (94) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (44)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Chromospheric H-alpha emission in F8-G3 dwarfs, and its connection with the T Tauri stars
Authors:
Herbig, G. H.
Affiliation:
AA(Lick Observatory, Santa Cruz, CA)
Publication:
Astrophysical Journal, Part 1 (ISSN 0004-637X), vol. 289, Feb. 1, 1985, p. 269-278. (ApJ Homepage)
Publication Date:
02/1985
Category:
Astrophysics
Origin:
STI
NASA/STI Keywords:
Chromosphere, H Alpha Line, Pre-Main Sequence Stars, Stellar Spectrophotometry, T Tauri Stars, Calcium, Dwarf Stars, Focal Plane Devices, Star Clusters
DOI:
10.1086/162887
Bibliographic Code:
1985ApJ...289..269H

Abstract

A chromospheric H-alpha emission core is measured in 40 stars of types F8-G3 V on the basis of observations obtained with dispersion 1.6 nm/mm, resolution 74 pm, and S/N 200-350 using a coude spectrograph on the 2.05-m reflector and a single-array 1872-channel Reticon in the focal plane of the 1-m camera at Lick Observatory on six nights during December, 1982 - June, 1983. An emission spike of about 100 pm, corresponding to surface flux 1.4 Merg/sq cm sec, is detected in the most active stars by subtracting the spectrum of the reference star Beta CVn. The data are presented in tables and graphs along with corresponding Ca II H, K data from Mount Wilson and analyzed in detail. It is found that main-sequence H-alpha surface-flux decay can be described by either a power law with exponent -0.4 and rms scatter factor 1.5 or an exponential relation with e-folding time 3-5 Gyr. Although extrapolation of the power law to very young stars correctly predicts the H-alpha fluxes of the T Tau stars, important differences (suggesting a different emission mechanism) are shown to make such extrapolation invalid.

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)

  New!

Find Similar Abstracts:

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