The brightest star of the night sky, Sirio, will surely draw your attention in the night sky at this time of the year. Once the sky darkens after 7:30 pm local time, Sirius will appear in the southeastern sky, in the lower left part of Orion. It has a radius 1.71 times that of the Sun and a surface temperature of 9,940 kelvins (K), which is more than 4,000 K higher than that of the Sun.
Sirius star, also called Alpha Canis Majoris or the Dog Star, brightest star in the night sky, with apparent visual magnitude −1.46. It is a binary star in the constellation Canis Major. The bright component of the binary is a blue-white star 25.4 times as luminous as the Sun. Its distance from the solar system is 8.6 light-years, only twice the distance of the nearest known star system beyond the Sun, the Alpha Centauri system. Its name comes from a Greek word meaning “sparkling” or “scorching.”
Sirius star is found in the constellation of the southern hemisphere of Canis Maior, Canis Mayor and is seen extraordinarily bright in the sky of the Earth. No matter where you live on Earth, follow the three medium-bright stars in the Orion Belt to locate Sirius.
Sirius star was known as Sothis to the ancient Egyptians, who were aware that it made its first heliacal rising (i.e., rose just before sunrise) of the year at about the time the annual floods were beginning in the Nile River delta.
February is perfect for both Northern Hemisphere and Southern Hemisphere observers to view the brightest star in the sky: Sirius star. As part of the constellation Canis Major the Greater Dog, Sirius star also earns the nickname of the Dog Star. From the Northern Hemisphere, Sirius arcs across in the southern sky. From the Southern Hemisphere, it swings high overhead. It’s always easy to spot as the brightest point of light in its region of sky (unless a planet happens to be near it, which none are in early 2023).
Finding Sirius Star
From the mid-northern latitudes such as most of the U.S., Sirius star rises in the southeast, arcs across the southern sky, and sets in the southwest. From the Southern Hemisphere, Sirius arcs high overhead.
As seen from around the world, Sirius rises in mid-evening in December. By mid-April, Sirius is setting in the southwest in mid-evening.
Sirius star is always easy to find. It’s the sky’s brightest star! Plus, anyone familiar with the constellation Orion can simply draw a line through Orion’s Belt to find this star. Sirius is roughly eight times as far from the Belt as the Belt is wide.
They long believed that Sothis caused the Nile floods, and they discovered that the heliacal rising of the star occurred at intervals of 365.25 days rather than the 365 days of their calendar year, a correction in the length of the year that was later incorporated in the Julian calendar. Among the ancient Romans, the hottest part of the year was associated with the heliacal rising of the Dog Star, a connection that survives in the expression “dog days.”
Sirius star and its companion revolve together in orbits of considerable eccentricity and with average separation of the stars of about 20 times Earth’s distance from the Sun. Despite the glare of the bright star, the eighth-magnitude companion is readily seen with a large telescope. This companion star, Sirius B, is about as massive as the Sun, though much more condensed, and was the first white dwarf star to be discovered.
In fact, these changes are simply what happens when such a bright star as Sirius star shines through the blanket of Earth’s atmosphere. The varying density and temperature of Earth’s air affect starlight, especially when we’re seeing the star low in the sky.
The Mythology of Sirius Star
Sirius is well known as the Dog Star, because it’s the chief star in the constellation Canis Major the Greater Dog. Have you ever heard anyone speak of the dog days of summer? Sirius star is behind the sun as seen from Earth in Northern Hemisphere summer. In late summer, it appears in the east before sunrise, near the sun in our sky. The early stargazers might have imagined the double-whammy of Sirius and the sun caused the hot weather, or dog days.
In ancient Egypt, the name Sirius star signified its nature as scorching or sparkling. The star was associated with the Egyptian gods Osiris, Sopdet and other gods. Ancient Egyptians noted that Sirius rose just before the sun each year immediately prior to the annual flooding of the Nile River. Although the floods could bring destruction, they also brought new soil and new life.
The Science of Sirius Star
At 8.6 light-years distance, Sirius is one of the nearest stars to us after the sun. By the way, a light year is nearly 6 trillion miles (9.4 trillion km)!
Sirius is classified by astronomers as an “A” type star. That means it’s a much hotter star than our sun; its surface temperature is about 17,000 degrees Fahrenheit (9,400 Celsius) in contrast to our sun’s 10,000 degrees F (5,500 C).
From Spain, Sirio should be visible during good part of winter and spring, being the period comprised between the end of the month of January and the middle of the month of March the interval of time most highlighted for your observation.
With slightly more than twice the mass of the sun and just less than twice its diameter, Sirius still puts out 26 times as much energy. It’s a main-sequence star, meaning it produces most of its energy by converting hydrogen into helium through nuclear fusion.
Sirius star is easily identifiable to the left and below the Belt of Orion. Generally speaking, it is very visible towards the end of the year in the Northern Hemisphere, since its luminosity dominates the night sky next to the Luna. This is all we know about her and her unique glow.
Osiris was an Egyptian god of life, death, fertility and rebirth of plant life along the Nile. Sopdet – who might have an even closer association with the Sirius star – began as an agricultural deity in Egypt, also closely associated with the Nile. The Egyptian new year was celebrated with a festival known as the Coming of Sopdet.
The Brightest star
Astronomers express the brightness of stars in terms of stellar magnitude. The smaller the number, the brighter the star.
The visual magnitude of Sirius star is -1.44, lower – brighter – than any other star. There are brighter stars than Sirius in terms of actual energy and light output, but they are farther away and hence appear dimmer.
Normally, the only objects that outshine Sirius star in our heavens are the sun, moon, Venus, Jupiter, Mars and Mercury (and usually Sirius outshines Mercury, too).
It is a brown pineapple that forms part of a double system and that has a surface temperature of 100 degrees centigrade. Unos astronomers han found the coldest star you know, with the temperature of a cup of you received hecho, said the same.
Not counting the sun, the second-brightest star in all of Earth’s sky – next-brightest after Sirius – is Canopus. It can be seen from latitudes like those of the southern U.S.