Is Sirius Part Of Orion?

Even if you don’t know much about constellations, it’s likely that you’ve heard of Orion. You probably already know how to spot it in the night sky, thanks to its distinctive belt made up of a trio of bright stars.

While you’d be forgiven for thinking that Sirius is part of this constellation, it’s actually situated in a whole different constellation of its own: Canis Major. 

Due to its close proximity to Orion, Sirius is often mistakenly identified as being part of it. While this isn’t the case, Sirius can still be used to help us spot Orion in the night sky.

In this article, we’ll explore just how close Sirius is to Orion and the many reasons why people seem to confuse the two. Read on to find out more about the Orion constellation and how to locate Sirius in the night sky tonight. 

What Is Orion?

Orion is one of the most well-known constellations in the observable universe and it can be seen without the use of a telescope from just about everywhere on Earth. Even if someone isn’t particularly knowledgeable or clued-up on stars and constellations, they can spot Orion in the night sky with ease. 

The constellation is named after a prominent figure in Greek mythology: Orion, the hunter. The link between the mythological man and the constellation was first established back in the Bronze Age, and we know this thanks to the Babylonian star catalogs.

Orion also had an important role in the formation of the Solar Egyptian calendar and it’s even referenced in the Bible on multiple occasions. 

The best time to observe Orion in the night sky is between the months of February and November. The quickest way to spot and identify the Orion Constellation is to pinpoint Orion’s Belt. 3 bright stars, Alnilam, Mintaka, and Alnitak, make up Orion’s Belt.

When you’re in the Northern Hemisphere, Orion can be found in the southwest and when you’re in the Southern Hemisphere, Orion would be in the northwest of the sky. It can be viewed best around latitudes 85 and -75 degrees. 

The stars in the Orion constellation make up different parts of the hunter. For example, Betelgeuse (the second brightest star in the constellation) is said to represent his right shoulder, whereas Bellatrix is his right.

The blade of the hunter’s sword is where Hatsya lies and his head is represented by a star called Meissa. Furthermore, Orion’s knees are represented by stars named Saiph and Rigel. 

What Is Sirius?

As mentioned earlier, Sirius is not part of the Orion constellation. Rather, it is situated in the constellation known as Canis Major, which translates to Greater Dog.

But you’d be forgiven for mistakenly categorizing Sirius as part of the Orion constellation as it sits very close by in the night sky. In fact, it also rises in the night sky at almost the same time as Orion, but it follows very closely behind.

The Belt of Orion can serve as a marker as it points directly to Sirius, which is located in the constellation Canis Major, the Greater Dog. Sirius is the brightest star seen in the sky at night.

It’s there before dawn during spring, but as the months pass, it’ll shift into the night sky. Each September, Orion can be seen in the sky in the morning, just before dawn has broken.

Even though our sun appears far brighter than Sirius in our sky, Sirius is actually much brighter: it’s just further away. In fact, it’s been theorized that Sirius is a mind-blowing 20 times brighter than the sun. 

However, it is still in the main sequence, which indicates that it is still consuming hydrogen in its center and has not yet grown into a massive phase. Therefore the star’s close proximity is the key reason for its stunning appearance from Earth.

Sirius is situated a modest 8.6 light-years away and is virtually an astronomical neighbor. There seem to be a handful of stars closer to us, notably the well-known Alpha Centauri cluster and a couple of red dwarfs, and yet none of these can compete with Sirius’ intensity, which is what makes all the difference.

Sirius, unlike our Sun, is not an isolated star. It’s part of a binary star system, and its sibling is a teeny (smaller than Earth!) white dwarf called Sirius B. But we prefer the adorable nickname, “The Pup.” Despite having roughly the same mass as the Sun, the Pup has collapsed and reduced in size, so it is now even smaller than Earth.

This makes it an extremely dense structure. It has a strong gravitational influence; in essence, it was by studying Sirius A’s back-and-forth oscillations that astronomers initially hypothesized way back in the early 1800s that another star was close. Sirius B is pale and dull in comparison to its partner, and it was found in 1862.

Sirius Mythology

It’s no wonder that Sirius has been significant to many civilizations and individual people over the years due to its luminosity. The constellation Orion was associated with a hunter in various ancient cultures, especially the Greeks, by which we inherited most of our astrological heritage.

He was followed through the skies by his four-legged friend, Canis Major (where Sirius is located). The star was connected to dogs in many traditions.

The brightest stars were associated with various mythological deities in ancient Egypt, notably Isis, Osiris, and Anubis, and the moment of its heliacal ascension was utilized as a periodic sign, alerting people of the rainy seasons of the Nile.

Nearer to home, the contemporary term “dog days of summer” was coined by the Greeks, who mistakenly believed that the star’s energy added to the intensity of the heat during the summer months.

How To Spot Sirius In The Night Sky

Sirius lies in the constellation Canis Major, which is relatively tiny. As winter is coming to a close, it can be seen in the night skies; in the summer months, it can be seen in the northeast in the pre-dawn periods.

Locating Orion, which occupies this area of the sky, is a simple method to find Sirius in the winter night skies. The dazzling star is located just southeast of Orion; in addition, the 3 stars in Orion’s belt could be and often are, used as a “guide” to Sirius. This is similar to how people use the Big Dipper constellation as a pointer to the North Star. 

Amateur astronomers may have difficulty recognizing planets from brilliant stars at first. Note the famous maxim: “Planets wouldn’t twinkle, only stars would.” This isn’t perfect since planets may sparkle if the environment is really chaotic, but it’s a solid starting point.

Sirius is well recognized for its dazzling sparkling and fast changes in brightness and hue. It’s entertaining to see, so take advantage of the opportunity!

However, don’t be disheartened if you don’t manage to catch a glimpse of The Pup.  Due to its companion’s brilliance, the feeble white dwarf is generally difficult to identify. To have a chance at capturing Sirius B, you’ll need to have a very big scope and ideal observing conditions.

Gordon Watts