Hindu texts Vedas: the Rigveda, the Yajurveda, the Samaveda and the Atharvaveda. Each Veda has been subclassified into four major text types – the Samhitas (mantras and benedictions), the Aranyakas (text on rituals, ceremonies, sacrifices and symbolic-sacrifices), the Brahmanas (commentaries on rituals, ceremonies and sacrifices), and the Upanishads (text discussing meditation, philosophy and spiritual knowledge). The Upanishads are a collection of Hindu texts which contain some of the central philosophical concepts of Hinduism. The Upanishads are commonly referred to as "Vedānta", variously interpreted to mean either the "last chapters, parts of the Veda" or "the object, the highest purpose of the Veda".
Ancient Iranian religion was invoked as the god who "best smite(s), who best destroy(s) the thief and the bandit at this trial." Astral deities figured more prominently in ancient Iranian religion than Vedic religion. This may be explained with the influence of Babylonian science on the Iranians, in particular the western groups. In the Avesta stars and constellations such as Ursa Major, the Pleiades, Vega, Fomalhaut and the Milky Way are mentioned. The most important astral deities seem to have been Tiri and Tishtrya. For reasons that are unknown, Tishtrya is associated with the star Sirius in one Yasht that is entirely devoted