heliacal

2 definitions found

heliacal - Collaborative International Dictionary of English v.0.48 :

  Heliacal \He*li"a*cal\, a. [Gr. ? belonging to the sun, fr. ?
     the sun: cf. F. h['e]liaque.] (Astron.)
     Emerging from the light of the sun, or passing into it;
     rising or setting at the same, or nearly the same, time as
     the sun. --Sir T. Browne.
     [1913 Webster]
  
     Note: The heliacal rising of a star is when, after being in
           conjunction with the sun, and invisible, it emerges
           from the light so as to be visible in the morning
           before sunrising. On the contrary, the heliacal setting
           of a star is when the sun approaches conjunction so
           near as to render the star invisible.
           [1913 Webster]

heliacal - WordNet (r) 2.1 (2005) :

  heliacal
      adj 1: pertaining to or near the sun; especially the first
             rising of a star after and last setting before its
             invisibility owing to its conjunction with the sun; "the
             heliacal rising of the Dog Star"; "the heliacal or Sothic
             year is determined by the heliacal rising of Sothis (the
             Egyptian name for the Dog Star)" [syn: heliacal,
             heliac]