Sirius is the brightest star in the night sky.
With a visual apparent magnitude of −1.46, it is almost twice as bright as Canopus, the next brightest star.
The name "Sirius" is derived from the Ancient Greek Σείριος Seirios ("glowing" or "scorcher").
Sirius appears bright because of both its intrinsic luminosity and its proximity to Earth.
At a distance of 2.6 parsecs (8.6 ly), the Sirius system is one of Earth's near neighbors.
Sirius is about twice as massive as the Sun and has an absolute visual magnitude of 1.42.
It is 25 times more luminous than the Sun
The heliacal rising of Sirius marked the flooding of the Nile in Ancient Egypt and the "dog days" of summer for the ancient Greeks,
Sirius, known in ancient Egypt as Sopdet (Greek: Sothis), is recorded in the earliest astronomical records.
During the era of the Middle Kingdom, Egyptians based their calendar on the heliacal rising of Sirius, namely the day it becomes visible just before sunrise after moving far enough away from the glare of the Sun.
This occurred just before the annual flooding of the Nile and the summer solstice,after a 70-day absence from the skies.
The hieroglyph for Sothis features a star and a triangle.
Sothis was identified with the great goddess Isis, who formed a part of a trinity with her husband Osiris and their son Horus, while the 70-day period symbolised the passing of Isis and Osiris through the duat (Egyptian underworld).
Many cultures have historically attached special significance to Sirius, particularly in relation to dogs.
Indeed, it is often colloquially called the "Dog Star" as the brightest star of Canis Major, the "Great Dog" constellation.
Sphinx is facing Sirius at the time when the star rises over the horizon at sunrise at the summer solstice, the time when the Nile started flooding, and the Egyptians probably held great ceremonies when that happened.
The day that the Star Sirius returned, appearing just ahead of the Sun at dawn, was considered to be the beginning of the ancient Egyptian New Year.
In our day and age, this day falls on or about August 1. Three thousand years ago this day occurred in early July.
This shift of dates is due to the apparent slow shifting of the stars from our point of view on earth.
Before the building of the Aswan Dam the Nile floods still began to rise and get their start in late June and by August 1st the inundation of the land of Egypt was going strong.
The ancient Egyptians believed that their most beloved Goddess, the Divine Mother, Isis, was the Soul of the Star Sirius and they saw Sirius as a cosmic manifestation of Her.
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