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Changes in X-ray brightness of a solar active region

Abstract

The soft X-ray flux in the waveband 0.3 to 0.9 nm has been monitored during most of the solar disk passage of McMath region 12094. These data show how the emission changed during quiet periods as well as during flaring. Throughout the first four days of observations the mean flux showed a gradual decay even though the magnetic region was still growing. At the end of this phase the region remained extremely inactive for almost half a day and then brightened by more than an order of magnitude within an hour. This enhancement lasted nearly one day and marked the onset of the break-up of the region. It is shown how this sequence of events might reflect the changes in subphotospheric convection pattern which Meyer et al (Mon. Not. R. Astr. Soc.; 169:35 (1974)) consider to develop in magnetic regions. It is also pointed out that the large flares in region 11976 during early 1972 August had a number of characteristics in common with the active phase discussed for region 12094.
Authors:
Glencross, W M; Brabban, D H [1] 
  1. University Coll., London (UK). Mullard Space Science Lab.
Publication Date:
Apr 01, 1976
Product Type:
Journal Article
Reference Number:
AIX-07-262001; EDB-77-020880
Resource Relation:
Journal Name: Mon. Not. R. Astron. Soc.; (United Kingdom); Journal Volume: 175:1
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; SOLAR ACTIVITY; RADIATION FLUX; SUN; CONVECTION; EMISSION; PHOTOSPHERE; RESOLUTION; SOFT X RADIATION; SOLAR FLARES; SOLAR RADIATION; VARIATIONS; ZONES; ATMOSPHERES; ELECTROMAGNETIC RADIATION; ENERGY TRANSFER; HEAT TRANSFER; IONIZING RADIATIONS; RADIATIONS; SOLAR ATMOSPHERE; STARS; X RADIATION; 640104* - Astrophysics & Cosmology- Solar Phenomena
OSTI ID:
7245371
Country of Origin:
United Kingdom
Language:
English
Other Identifying Numbers:
Journal ID: CODEN: MNRAA
Submitting Site:
INIS
Size:
Pages: 33-42
Announcement Date:
Oct 01, 1976

Citation Formats

Glencross, W M, and Brabban, D H. Changes in X-ray brightness of a solar active region. United Kingdom: N. p., 1976. Web.
Glencross, W M, & Brabban, D H. Changes in X-ray brightness of a solar active region. United Kingdom.
Glencross, W M, and Brabban, D H. 1976. "Changes in X-ray brightness of a solar active region." United Kingdom.
@misc{etde_7245371,
title = {Changes in X-ray brightness of a solar active region}
author = {Glencross, W M, and Brabban, D H}
abstractNote = {The soft X-ray flux in the waveband 0.3 to 0.9 nm has been monitored during most of the solar disk passage of McMath region 12094. These data show how the emission changed during quiet periods as well as during flaring. Throughout the first four days of observations the mean flux showed a gradual decay even though the magnetic region was still growing. At the end of this phase the region remained extremely inactive for almost half a day and then brightened by more than an order of magnitude within an hour. This enhancement lasted nearly one day and marked the onset of the break-up of the region. It is shown how this sequence of events might reflect the changes in subphotospheric convection pattern which Meyer et al (Mon. Not. R. Astr. Soc.; 169:35 (1974)) consider to develop in magnetic regions. It is also pointed out that the large flares in region 11976 during early 1972 August had a number of characteristics in common with the active phase discussed for region 12094.}
journal = []
volume = {175:1}
journal type = {AC}
place = {United Kingdom}
year = {1976}
month = {Apr}
}