Sirius is the brightest star in the night sky. Its name is derived from the Greek word Seirios, which means ‘glowing’ or’scorching’ It is 25 times more luminous than the Sun, but has a significantly lower luminosity than other bright stars such as Canopus or Rigel. Its displacement from the ecliptic causes its heliacal rising to be remarkably regular.
About Sirius in brief
Sirius is the brightest star in the night sky. Its name is derived from the Greek word Seirios, which means ‘glowing’ or’scorching’ It is 25 times more luminous than the Sun, but has a significantly lower luminosity than other bright stars such as Canopus or Rigel. Its displacement from the ecliptic causes its heliacal rising to be remarkably regular compared to other stars, with a period of almost exactly 365. 25 days. This rising occurs at Cairo on 19 July, placing it just prior to the onset of the annual flooding of the Nile during antiquity. The Egyptians continued to note the times of Sirius’s annual return, which may have led them to the discovery of the 1460-year Sothic cycle and influenced the development of the Julian and Alexandrian calendars. The Greeks observed that the appearance of Sirius heralded the hot and dry summer and feared that it caused plants to wilt, men to weaken, and women to become aroused. The inhabitants of the island of Ceos in the Aegean Sea would offer sacrifices to Sirius and would await the reappearance of the star in summer. If it was clear, it would end good fortune; if it was misty or faint, it foretold pestilence. The Romans used it as the location for the central meridian in his Almagest. He depicted it as one of six red stars in his Book of Plemy, which he used for the map of the globe in Books VIII and VIII.
He also used it for the location of the red meridian for the globe’s central meridians in Books VII and VII. It is known colloquially as the ‘Dog Star’ due to its prominence in its constellation, Canis Major. To the Polynesians, mostly in the Southern Hemisphere, the star marked winter and was an important reference for their navigation around the Pacific Ocean. To Greek observers, this signified emanations that caused its malignant influence. Anyone suffering its effects was said to be’star-struck’. It was described as ‘flaming’ in literature. It was worshipped by the ancient Egyptians as the goddess Sopdet, guarantor of the fertility of their land, and was seen to twinkle more in the unsettled weather conditions of early summer. Sirius A is about twice as massive as the Sun and has an absolute visual magnitude of +1. 42. It will continue to be the brightestStar in the Earth’s night sky for the next 210,000 years. Its distance will begin to increase, and it will become fainter, but it will remain bright for the rest of its life. The Sirius system is between 200 and 300 million years old and is composed of two bright bluish stars. The more massive of these, Sirius B, consumed its resources and became a red giant before shedding its outer layers and collapsing into its current state as a white dwarf around 120 million years ago.