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)
· On-line Data
· References in the article
· Citations to the Article (8) (Citation History)
· Refereed Citations to the Article
· Associated Articles
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Properties of cool flare with GOES class B5 to C2.
Authors:
Phillips, K. J. H.; Feldman, U.
Publication:
Astronomy and Astrophysics, v.304, p.563 (A&A Homepage)
Publication Date:
12/1995
Origin:
A&A via CDS; KNUDSEN
A&A Keywords:
SUN: FLARES, SUN: X-RAYS
Bibliographic Code:
1995A&A...304..563P

Abstract

Observed parameters for 208 small flares with GOES classification B5 to C2 are discussed using data from the broad-band detectors on the Geostationary Operational Environmental Satellites (GOES) and the Bragg Crystal Spectrometer (BCS) on the Yohkoh solar flare spacecraft. Peak temperatures derived from He-like sulfur spectra are in the range 8+/-2x10^6^K and are similar to those derived from the ratio of the 1-8A and 0.5-4A GOES channels, but a little less than those from He-like calcium spectra, showing that even these small flares are non-isothermal. The absence of He-like iron emission shows that the temperatures are less than 14x10^6^K. There is a slight positive correlation between temperature and emission measure from the calcium and sulfur data. Differences in this distribution and that derived for larger flares in a separate study can be reconciled in terms of the fact that temperatures were measured from He-like iron spectra for the larger flares. The emission measure of the flares in our sample are correlated with GOES class. A detailed study of a subset of 20 flares shows that the temperatures generally reach peak flux slightly before (up to 30s) or coincident with the light curve maximum. It is found that even small flux enhancements which are frequently present are associated with temperature enhancements.

Associated Articles

Source Paper     Catalog Description    

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