Also found in: Thesaurus, Encyclopedia, Wikipedia.
Related to heliacal: Heliacal setting


Of or relating to the sun, especially rising and setting with the sun.

[From Late Latin hēliacus, from Greek hēliakos, from hēlios, sun; see sāwel- in Indo-European roots.]

he·li′a·cal·ly adv.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(hɪˈlaɪ ə kəl)

pertaining to or occurring near the sun, esp. applied to such risings and settings of a star as most nearly coincide with sunrise or sunset.
[1600–10; < Late Latin hēliac(us) (< Greek hēliakós; see helio-, -ac) + -al1]
he•li′a•cal•ly, adv.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
ThesaurusAntonymsRelated WordsSynonymsLegend:
Adj.1.heliacal - 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)"
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.
References in periodicals archive ?
The conventional Egyptian chronology (whether high or low) rests on the so-called Sothic hypothesis, wherein it is assumed that throughout the history of Dynastic Egypt the civil year was taken to be exactly 365 days long, and that as a result it slipped forward continuously across the seasons in a 1460-(Julian) year-long cycle (the period between successive heliacal risings of Sirius on the first day of the civil calendar) without a single adjustment of any sort ever.
When the planet reappears again for the first time and rises in the morning sky just moments before the sun, for the first time in many months after having been hidden in the sun's glare for those many months, that moment is known to astrologers as a heliacal rising.
Recognizing that this number was almost identical to the synodic period of Venus (583.92 days, the time it takes for Venus to return to the same position as seen from Earth), Forstermann determined that the red numbers--236, 90, 250, and 8--marked four significant points in the planet's cycle: its morning heliacal rising; its disappearance at superior conjunction; its first evening rise; and its disappearance at inferior conjunction.
These include Critically Endangered: caracal (Felis caracal) and white- backed vulture (Gypus bengalensis); Endangered: Indian wolf (Canis lupus pallipes); Vulnerbale: hog deer (Axis porcinus), marbled teal (Marmaronetta angustirostris), Pallas's fish eagle (Haliaeetus leucoryphus), imperial eagle (Aquila heliacal), saker falcon (Falco cherrug), houbara bustard (Chlamydotis undulata), Sindh babbler (Chrysomma altirostre) and Indian marsh crocodile (Crocodylus palustris) (Table 2).
The traditional 40-day period of dog days once coincided with the heliacal (at sunrise) rising of Sirius.
Brophy further suggests that other stones indicate an alignment with the heliacal rising of specific stars at the vernal equinox, events which occur once every 25,900 years.
They look at Egyptian chronological tradition and method of dating, relative chronology such as dynasties, and absolute chronology such as dendrology and the heliacal rising of Sirius.
Although Rochberg gives clear explanations of such words as "ecliptic," "heliacal," and "synodic," charts and illustrations would have been helpful for the reader who is interested in astrology but who is not versed in astronomical terms.