Definitions

from The American Heritage® Dictionary of the English Language, 5th Edition.

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

from The Century Dictionary.

  • In old astronomy and chronology, near the sun: applied to those risings and settings of a star which were as nearly coincident with those of the sun as they could be observed.

from the GNU version of the Collaborative International Dictionary of English.

  • adjective (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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

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

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • adjective 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

Etymologies

from The American Heritage® Dictionary of the English Language, 4th Edition

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

Examples

  • The more precise fixing of new year's day was accomplished through observation of the time of the so-called heliacal rising of the dog-star, Sirius, which bore the Egyptian name Sothis.

    A History of Science: in Five Volumes. Volume I: The Beginnings of Science

  • In some cases the ancients took the sidereal year from the "heliacal" risings or settings of stars, that is from the interval between the time when a bright star was first seen in the morning just before the sun rose, until it was first so seen again; or last seen just after the sun set in the evening, until it was last so seen again.

    The Astronomy of the Bible An Elementary Commentary on the Astronomical References of Holy Scripture

  • These are the dog days, the days about the heliacal rising of the Dog Star, noted from ancient times as the hottest and most unwholesome period of the year, a period when malevolent influences were thought to prevail.

    Nature, Bounteous « Tales from the Reading Room

  • It is likely that what this refers to was a heliacal rising, which is the first time that a star appears over the horizon during the course of a year.

    Valerie Tarico: Ancient Mythic Origins of the Christmas Story

  • When it starts its heliacal rise from the east it is ahead of the sun by about 11 degrees, moving across the celestial sphere to set in the west.

    Archive 2008-06-01

  • As they arrive the sun is still below the horizon, and they gaze impatiently for the apparent heliacal rising of the Dog Star.

    Archive 2008-06-01

  • The Egyptians referred to the heliacal rising and its associated festival as prt spdt, "the going forth of Sepdet".

    The Sirius Lore

  • The Egyptians referred to the heliacal rising and its associated festival as prt spdt, "the going forth of Sepdet".

    Archive 2008-06-01

  • When it starts its heliacal rise from the east it is ahead of the sun by about 11 degrees, moving across the celestial sphere to set in the west.

    The Sirius Lore

  • As they arrive the sun is still below the horizon, and they gaze impatiently for the apparent heliacal rising of the Dog Star.

    The Sirius Lore

Comments

Log in or sign up to get involved in the conversation. It's quick and easy.

  • "... in astronomy, a term applied to the rising or setting of the stars, or more strictly speaking, to their emersion out of and immersion into the rays and superior splendor of the sun.

    "A star is said to rise heliacally, when, after having been in conjunction with the sun, and on that account invisible, it comes to be at such a distance from him, as to be seen in the morning before sun-rising; the sun, by his apparent motion, receding from the star towards the east: on the contrary, the heliacal setting is when the sun approaches so near a star as to hide it with his beams, which prevent the fainter light of the star from being perceived, so that the terms apparition and occultation would be more proper than rising and setting."

    Falconer's New Universal Dictionary of the Marine (1816), 191

    See also acronical.

    October 11, 2008