Heliacal

2 definitions found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  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]

From WordNet (r) 2.0 [wn]:

  heliacal
       adj : 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: {heliac}]