If you have an interest in astronomy, you would always be eager to view Sirius.
You can view Sirius by pointing telescope at it. Sirius is located in the constellation Canis Major, the Greater Dog. That is why Sirius is known as the Dog Star.
Those, who reside in the Northern Hemisphere, can see it in the southeast or southwest direction. And the right time to view in the night is the month of February.
It could be a stimulating experience to view Sirius before dawn in the summer months (July/August).
In the Greek language, Sirius means ‘glowing,’ and the name justifies for it is the brightest star in our sky!
Since the early days, people were interested to know about this star because they could identify Sirius distinctly in the night sky.
There are several reasons why Sirius is so visible in the sky. The foremost is that the star is only 8.6 light years away from the Earth; in the space, this is not very high distance by any standards.
Experts from the NASA reveal that it is two times as large as our Sun. In luminosity, it beats our Sun by a great margin of over 2000 percent!
Sirius is estimated to be only 225-250 million years old meaning it is much younger than our Sun. Sirius will burn out its hydrogen in one billion years to turn a red giant!
There is a relation between the mass of a star and its luminosity (the light that it produces) if the mass of the star increases by ten times its luminosity will increase by one thousand times.
While more massive stars have a bluer appearance, less massive stars will appear reddish. Our Sun is in between the two with a yellowish appearance!
The Egyptians also called it the “Nile Star” for its appearance coincided with the rise of waters in the Nile River that nourished their farmlands. They even based their calendars on the basis of its becoming visible for the first time before sunrise.
It was not until 1862 when a companion star Sirius B was discovered by the US astronomers.
It will be interesting to know that Sirius B is a White dwarf star. Once it was a main-sequence star as our Sun. Main sequence stars are those that fuse hydrogen atoms in their cores producing helium atoms.
Sirius B will go dimmer and dimmer over time, and when its fuel is completely burned out, it will turn dark. Then it would be known as the black dwarf star! Each star has to go with similar cycles.
Currently, scientists study white dwarfs such as Sirius B so that they may gain more understanding of the entire life cycle of the stars. Our Sun will also go to the same cycle and turn white dwarf someday!
Based on mass and temperature of Sirius B, scientists calculate that Sirius became a white dwarf some 124 million years ago. Before becoming a White dwarf, it remained a red giant for some 110-120 million years. Even today its mass is as much as of our Sun.
When we view these twin stars in the telescope, we will find them 16-18″ apart. From the Northern Hemisphere, they can be seen at around 26 degrees to 28 degrees latitude.
Sirius A is so bright that we may need to magnify objects 300x to locate Sirius B!
Sirius in Ancient Cultures
It will be interesting to know how different regions/countries in ancient times looked at this star!
In China, it is known as the star of the “celestial wolf.”
In ancient China, people envisioned a huge bow and arrow like figure in the southern sky. This picture emerged from the combination of Canis Major and Puppis. The tip of the arrow directed towards the wolf Sirius.
During 4000 B.C, the epic poem Gilgamesh has a mention of a heavy star, which is Sirius. According to the epic poem, the star is described as ‘the God of heaven’ full of essence.
Muslim scripture the Quran also has a mention of Sirius in Surah 53 where it is called al-shi’raa.
Even red Indians, the indigenous peoples of North America, fully knew about Sirius – the mighty star that existed in the southern sky.
They associated the star with a combination of bow and arrow. The tribe of Nebraska knew it as the “Wolf Star.” Many others called it the “Coyote Star.” In Alaska, they called it the “Moon Dog.”
In ancient Greece, the appearance of Sirius is marked as the beginning of summer. ‘The Dog Days of Summer’ was the phrase used by them on the reappearance of Sirius.
They also feared that its arrival would weaken men and wither plants. In their ancient literature, it is depicted as a flaming or burning star.
The Polynesians, the inhabitants of islands in the central and southern Pacific Ocean, used the star for navigation purposes. Lying low on the horizon Sirius acted as a compass for them to navigate in the sea; the star served as latitude marker and helped them to reach their destination.
The indigenous people in the islands of Kea equated the reappearance of the star in summer with good fortunes. Any dim reappearance of Sirius would be called a signal of bad omen! They would offer sacrifices to Sirius as an act of benevolence!
Sometimes in the Month of April, Romans would sacrifice a sheep and dog to their goddess ‘Robigo’ so as to protect their wheat crop from the emissions of Sirius.
In the 2nd century AD, in Alexandria, Claudius Ptolemy had associated the globe’s central meridian with Sirius as revealed in his Books VII and VIII; he mentioned Sirius as one of six red-colored stars.
In Africa, the Dogons, the West African tribe worship Sirius for thousands of years; they recognize the twin stars for ages.
According to them, though Sirius B is invisible and small yet very powerful! As per their belief, God Nommo came to this planet in a space ship from these twin stars. Sirius is a key axis of the universe, and all earthly souls and matters have arrived from there.
Egyptian astronomy has given significant importance to Sirius!
In the ancient times, they strongly associated the reappearance of Sirius with the rise of the Nile River. The first night when Sirius was noticed was known as the ‘heliacal rising,’ and this occurred in the month of July. Then, Egyptians would mark it as the beginning of the New Year to celebrate it as ‘The Coming of Sopdet.’
Sopdet is the ancient name of the star in Egypt, which is personified as the Egyptian Goddess! In subsequent times, she turned a nursing mother or Mother Goddess, perhaps because of her connection with Goddess Isis.
Due to flooding in the Nile, Sopdet came to be known as the symbol of fertility. She became a goddess of fertility not for the living but for the dead too as she would cleanse pharaoh after their death. As the embalming of the dead would take seventy days, Sirius would also reappear after the same amount of time, hence this association.
In the ancient religious texts dating back 2400-2300 BC, also known as the Pyramid Texts in Egypt, she is believed to be a pathfinder for pharaoh in the afterlife to become the imperishable stars. She is believed to be living on the horizon!
The legend had it that the pharaoh had a child from Sopdet!