Night Sky Photography -- 01-02-2024 -- Let's Talk About The Stars Of The Winter Triangle

Good evening fellow stargazers, and Happy New Year 2024!

Late last night, under beautifully clear starry skies here in upstate South Carolina, I photographed the major stars of the Constellations Orion The Hunter and his two dogs: Canis Major (The Greater Dog) and Canis Minor (The Lesser Dog) highlighting the position of the Winter Triangle that connects these three constellations.

For those of y'all who follow my night sky photography here on this blog site, you should be more than familiar with the Winter Triangle asterism. I've taken and outlined the three major stars that make up the Winter Triangle and their positions among their star constellations on several occasions.

Now that the winter season is in full swing here in North America, this is the best time of the year to talk about the three major stars of the Winter Triangle and some really interesting facts about these heavenly bodies.

One major fact about these stars is that all of them are much larger than our own bright yellow Sun. Two of the stars are almost double the size of the Sun and the final one is so large it would engulf half of our Solar System itself.

Let's begin with Sirius, the largest star in the Winter Triangle -- as well as the largest and brightest star visible in the night sky from here on the surface of the Earth.

Sirius (actual designation among astronomers by the Bayer designation Alpha Canis Majoris, or a Canis Majoris) is a bright bluish main-sequence star about twice the size of our own Sun and about 20 times as luminous. Its name is derived from the Greek word Seirios, meaning glowing. Sirius is nicknamed "The Dog Star" because of its position in the constellation Canis Major (The Greater Dog).

Sirius is also a binary star system, meaning there are in fact two stars. Bright Sirius A is the bright star visible here on Earth, while Sirius B is a smaller white dwarf companion that is barely visible through a good telescope. Sirius B (nicknamed "The Pup") is believed to be nearly the diameter of the Earth (7,500 miles, or 12,000 kilometers) and 10,000 times dimmer than Sirius A.

Both Sirius A and Sirius B orbit each other every 50 years at a distance of somewhere between 8.2 and 31.5 astronomical units -- roughly the distance between the planets Saturn and just between Neptune and Pluto in our own Solar System. At a distance of roughly 8.6 light-years, (or about 2.64 parsecs), the binary Sirius system is one of Earth's closest interstellar neighbors.

The next closest point of the Winter Triangle is the bright star Procyon (also known as Alpha Canis Minoris, or a Canis Minoris) in the smaller constellation Canis Minor (The Lesser Dog). The name is derived from the Greek word Prokyon, meaning "before the dog", since it seemingly precedes the "Dog Star" Sirius as it travels across the sky due to rotation of the Earth.

Procyon is relatively close to our Solar System at a distance of about 11.46 light-years (or 3.51 parsecs) from the Sun. Procyon is usually the 8th brightest star in the night sky, with the best magnitude for brightness around the middle of January every year.

Just like Sirius, Procyon is also a binary star system made up of two stars: Procyon A, which is a white main-sequence star; and Procyon B, which is a much smaller white dwarf star. Procyon A is estimated to be 1.4 times larger than our Sun, while Procyon B is just smaller than the Earth at about 5,300 miles (or 8,528 km). Both stars are separated by about 15 AUs -- about the distance between Saturn and Uranus in our Solar System -- and orbit each other once every 40 years.

Finally, we have the bright star, Betelgeuse, located in the upper part of the constellation Orion the Hunter. The name was derived from the Arabic phrase Yad al-Jawza' or "the hand of al-Jawza".

Betelgeuse is a red supergiant star and the 10th brightest star in the night sky visible from the Earth's surface. Also known to astronomers as Alpha Orionis, or a Orionis, its the largest star in the constellation Orion as well as the largest in the Winter Triangle. It sits at a whopping 642 light-years (or, 40.6 million AUs) distance from the Sun.

Betelgeuse's diameter is approximately 760 million miles (or about 1.2 billion km, or 8.1 AU) across and is somewhere around 700 times as massive as the Sun. To put that in cosmic perspective, if Betelgeuse replaced our Sun in the Solar System, its circumference would engulf all of the four inner planets and the Asteroid Belt and would be just inside the orbit of Jupiter.

Despite being the largest star in the constellation, Betelgeuse is the second brightest star in Orion after the white supergiant star, Rigel, which sits near the bottom of the constellation. Although Betelgeuse is actually larger in terms of diameter, in terms of actual mass and energy output, Rigel is the king of Orion.

This huge red star is actually in the final stages of its life and is expected to become a supernova explosion at some point in the next 100,000 years.

So, when looking up at the winter constellations late at night over the next few months, really consider the size of those bright, beautiful points of light that make up the Winter Triangle.