Solar X-Ray Bright Points

Abstract

Preliminary analysis of photographs from the 8-054 X-ray telescope aboard Skylab has shown that bright points have a statistical distribution of lifetimes with a mean of eight hours. The lifetime of a bright point is approximately proportional to its maximum area, which is typically 2 X 108 km2. A small bright core generally develops during the middle part of the bright-point lifetime with area 10 km2. A small fraction of bright points are seen to increase their surface brightness by several orders of magnitude on a time scale of minutes. These "flares" occur at all latitudes from the equator to the poles. To first order, bright points are uniformly distributed across the solar surface. An estimated 1500 X-ray bright points emerge per day, possibly bringing more new magnetic flux to the surface than is contributed by the major active regions. Sukiect headings: X-rays, solar