Almucantar

The celestial sphere with the zenith and almucantar marked in red, the horizon in green, and the path of a star or the Sun in blue.

An almucantar (also spelled almucantarat or almacantara) is a circle on the celestial sphere parallel to the horizon. Two stars that lie on the same almucantar have the same altitude.

The term was introduced into European astronomy by monastic astronomer Hermann Contractus of Reichenau, Latinized from the Arabic word al-muqanṭarah ("the almucantar, sundial", plural: al-muqanṭarāt), derived from qanṭarah ("arch, bridge")[1][2]

  1. ^ "almucantar". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  2. ^ "almucantar". Merriam-Webster.com Dictionary. Merriam-Webster.