Stellar classification



  • X -4
  • Y -23
  • Z 10
→ Sol: 25

Object type

  • Double or multiple star
  • Star
  • Infra-Red source
  • High proper-motion Star
  • sub-millimetric source
  • UV-emission source
  • Variable Star
simbad:* alf PsA


Fomalhaut, also designated Alpha Piscis Austrini (α Piscis Austrini, abbreviated Alpha PsA, α PsA) is the brightest star in the constellation of Piscis Austrinus and one of the brightest stars in the sky. It is a class A star on the main sequence approximately 25 light-years (7.7 pc) from the Sun as measured by the Hipparcos astrometry satellite. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. It is classified as a Vega-like star that emits excess infrared radiation, indicating it is surrounded by a circumstellar disk. Fomalhaut, K-type main-sequence star TW Piscis Austrini, and M-type, red dwarf star LP 876-10 constitute a triple system, even though the companions are separated by several degrees.

Fomalhaut holds a special significance in extrasolar planet research, as it is the center of the first stellar system with an extrasolar planet candidate (designated Fomalhaut b, later named Dagon) imaged at visible wavelengths. The image was published in Science in November 2008. Fomalhaut is the third-brightest star (as viewed from Earth) known to have a planetary system, after the Sun and Pollux.

This article uses material from the Wikipedia article "Fomalhaut", which is released under the Creative Commons Attribution-Share-Alike License 3.0.