July 1st was the festival of Tištar, literally “Tri Star,” an astral god being or yazatá (worthy of adoration.) Tištar is the luckiest and most brilliant star in the night sky. The eighth song in the beautiful Avestan mythopoetic Yašt collection is dedicated to Tištar. Also the 13th day of each Avestan Month is dedicated to Tištar. Hence number 13 is a lucky number among Zoroastrians.
Forssman (1968) puts the star Sirius in a direct and clear relationship with the three stars of Orion’s Belt (delta, epsilon, zeta Orionis.) Sirius would have been named as “the one who belongs to the three stars.” In the Vedic literature, the asterism of Orion’s Belt was represented as an arrow called iṣus trikāṇdā, shot by Tiṣya (or Rudra) towards Prajāpati.
According to Tištar Yašt 6-7 and 37-38, Tištar flies in the sky as the arrow shot by the most valiant archer of the Aryans, the hero erexša literally bear (Kellens 1977). Tištar combats apaôša “drought, scorching heat” and ominous shooting stars.
Tištar assumes the form of a fifteen-year-old young man, a virile bull with golden horns, and a splendid white horse to combat his antagonist apaôša “drought” who appears in the form of a black and gloomy horse. Each form takes ten days.
These three transformations astronomically cover the period beginning with the rising of the star Sirius in July and lasting till the first appearance of the meteor showers between August and September (Panaino, 1995, pp. 15-24).
Tištriia and the other stars are called afšciθra- in the Avesta. The epithet afšciθra translates into “having the seed/origin” of the waters/rains and/or “having the brilliance of the waters/rains.”
In Greek Mythology Astér Seirios is daughter of the Titan Atlas.
Homer, Iliad 5. 10 ff (trans. Lattimore) (Greek epic C8th B.C.):
“The star of the waning summer [Seirios, the Dog-Star] who beyond all stars rises bathed in Okeanos (the ocean stream) to glitter with brilliance.”
Homer, Iliad 22. 26 ff :
“That star [Seirios, the dog-star] which comes on in the autumn and whose conspicuous brightness far outshines the stars that are numbered in the night’s darkening, the star they give the name of Orion’s Dog (kynos Orionos), which is brightest among the stars, and yet is wrought as a sign of evil and brings on the great fever for unfortunate mortals.”
Book XXII Illiad:1-89
The aged Priam was the first of all whose eyes saw him / as he swept across the flat land in full shining, like that star / which comes on in the autumn and whose conspicuous brightness / far outshines the stars that are numbered in the night’s darkening, / the star they give the name of Orion’s Dog, which is brightest / among the stars, and yet is wrought as a sign of evil / and brings on the great fever for unfortunate mortals. / Such was the flare of the bronze that girt his chest in his running
Interestingly, for Ancient Iranians Orion’s Tri Star is not only the brightest but the luckiest star in firmament.
In the Silmarillion (1977), a compendium of mythopoeic work by Tolkien Sirius is called Helluin by the Elves, who awoke to the world “when first Menelmacar strode up the sky and the blue fire of Helluin flickered in the mists above the borders of the world…