Eta Cassiopeiae

Achird is the proper name of the star η Cassiopeiae in the constellation Cassiopeia.

Achird is a double star in 19.3 light years away, consisting of a 3.5 m bright star of spectral type G0 (yellow) and a 7.5 m bright star of spectral K7V (orange). To auflzulösen the system into single stars, one needs a telescope of at least 5 cm lens diameter. The color contrast between the two components makes Achird to a charming observation object.

The angular separation and the position angle of the companion star change over time:

  • Year angular separation position angle
  • 1990 12.5 " 312 degree
  • 2010 13.2 " 322 degree

Coordinates for the equinox 2000:

Binary star Light-year Minute of arc#Symbols and abbreviations
27161
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