Accession Number : ADA308095

Title :   Chromospheric Activity in Algol Binaries.

Descriptive Note : Final rept. 1 Oct 91-30 Sep 95,

Corporate Author : VIRGINIA UNIV CHARLOTTESVILLE

Personal Author(s) : Richards, Merecedes

PDF Url : ADA308095

Report Date : 30 SEP 1995

Pagination or Media Count : 31

Abstract : Algol-type binary star systems contain a cool Sun-like star and a hotter blue star. The cool star has a magnetic field many times more powerful than that of our Sun, with starspots that are similar to sunspots. The magnetic fields of Algol binaries are powered by the rapid rotation of the cool star. In the short-period Algols, the cool star rotates once every 6 days or less while our Sun rotates much more slowly once every 28 days. This difference in rotation rates can account partially for the differences which we see in the magnetic structures like the chromosphere and corona. These short-period Algols contain a stream of gas which is stripped off the cool star by the gravitational pull of the hotter blue star, strikes the hot star, then circles it to form an asymmetric ring of gas. Mercedes Richards was the first astronomer to discover starspots on the cool star in an Algol binary. More importantly, she has been trying to understand how the extensive magnetic field of a star like our Sun would affect the flow of gas between the two stars, and especially the blue star. She was also the first astronomer to produce a reconstructed Doppler (velocity) image of gas streams in the class of interacting binaries, and also first to image the chromospheres and accretion disks in Algol binaries. This information will help us to understand how Sun-like stars influence the evolution of a binary system.

Descriptors :   *BINARY STARS, *CHROMOSPHERE, REPRINTS, MAGNETIC FIELDS, ASYMMETRY, ROTATION, GAS FLOW, SUNSPOTS.

Subject Categories : Astronomy
      Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE