heliacal rising


Also found in: Encyclopedia, Wikipedia.

heliacal rising

(hɪˈlaɪəkəl)
n
1. (Astronomy) the rising of a celestial object at approximately the same time as the rising of the sun
2. (Astronomy) the date at which such a celestial object first becomes visible in the dawn sky
[C17: from Late Latin hēliacus relating to the sun, from Greek hēliakos, from hēlios the sun]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
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. A heliacal rising, that special first reappearance of a planet, is what en te anatole referred to in ancient Greek astrology.
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.
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.
The magi were speaking of a star in its "heliacal rising," in the morning, in the East, a fairly precise distance ahead of the sun at dawn.
In the present work, planetarium software is used to simulate heliacal rising and setting dates of stars in the Mayan sky and the results compared to earlier mathematical calculations and ancient Mayan texts.
To forestall this, the holidays--or "feasts" as they seem to have been called--were regulated by the Moon, usually dating the first of each month by the first invisibility of the old lunar crescent just before sunrise, as well as the heliacal rising of Sirius in midsummer.
The full text of MUL.APIN, known from several larger tablets, contains a wealth of astronomical information, including the names of the major stars and constellations; the heliacal rising dates of important stars; lists of stars and constellations that rise, culminate, or set at the same time; and methods for determining the positions and movements of the Sun, Moon, and planets.
11 DAWN: On this or the next few mornings watch the east-southeast horizon about 20 minutes before sunrise for the heliacal rising (first visibility) of Sirius as it emerges from the Sun's glare.
11 DAWN: On this or the next few mornings, look low in the east-southeast about 20 minutes before sunrise for the heliacal rising (first dawn visibility) of Sirius as it emerges from the Sun's glare.
86637, and (8), a similar table from Tanis, are discussed in the general survey;] (9) Papyrus Carlsberg 9; (10) Sothic dates, i.e., Egyptian dates of the heliacal rising of Sirius (Greek Sothis); (11) the decanal clock on Meshet's coffin; (12) the Book of Nut; (13) the dramatic text in Seti I's cenotaph; (14) the Ramesside star clock; (15) Amenemhet's water clock; (16) the shadow clock in Seti I's cenotaph; (17) the zodiacs in the temples at Esna and Dendera; and (18) the statue of the astronomer Harkhebi.