DICT.TW Dictionary Taiwan

 he·li·a·cal /hɪˈlaɪəkəl/
 (a.)太陽的,和太陽同時或幾乎同時出沒的

 He·li·a·cal a.  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.
 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.
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 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]