The Supergiant Stars Of The Constellation Orion

One of the most easily recognizable constellations in our night sky is Orion The Hunter, especially here in North America during the winter months. 

The constellation, made up of a quadrangle of four bright stars in our evening sky shaped like an hour glass with three additional evenly spaced stars making up the center (or belt), gives Orion its distinctive look. Although they look like tiny dots of light in our evening sky here on Earth, all of them are actually much larger than our own yellow Sun.

While the G-type main-sequence star that inhabits the center of our own Solar System seems huge -- and make no mistake it is compared to the rest of the planets that orbits it -- next to the Constellation Orion stars, its relatively small in terms of scale and mass. 

Here are a few fun scientific facts about each of these bright stars.

Rigel (or Beta Orionis) is generally the seventh-brightest star in the night sky and the brightest star in Orion. Rigel is a spectral type B8Ia blue supergiant (BSG) star approximately 120,000 times as luminous as our own Sun and is 18 to 24 times as massive in scale.

It is the brightest and largest component of a star system of at least four stars that appear as a single blue-white point of light to the naked eye as seen here on Earth. The three smaller stars of this system are all blue-white main-sequence stars, each three to four times as massive as the Sun.

The Rigel system is located at a distance of approximately 860 light-years (or 260 parsecs) from the Sun.

Betelgeuse (or Alpha Orionis) is a red supergiant star that is the second-brightest star in the constellation, and the tenth-brightest star in the night sky. It is also the largest star in Orion with an estimated radius between 640 and 764 times that of the Sun -- which would roughly be the distance between the center of our Sun to the somewhere between the orbits of Mars and Jupiter!

Betelgeuse lies about 642 light-years (or 197 parsecs) from our Solar System. Because Betelgeuse is a red supergiant, while it is much larger and closer to us than Rigel, it burns less brightly due to the late stage of its celestial lifespan.

Size comparison of Betelgeuse and Rigel compared to our Sun
and other stars.

Bellatrix (or Gamma Orionis) is the third-brightest star in Orion, and typically the 25th-brightest star in our night sky. Bellatrix is a B2 III-type giant star about six time the size of our own yellow Sun, and located about 244 light-years (or 75 parsecs) from the Sun, making Bellatrix the closest of the Orion constellation stars to our Solar System.

Saiph (or Kappa Orionis) is the other blue supergiant star that makes up the forth star in the constellation's main quadrangle. It is the sixth-brightest star in Orion with an estimated distance of about 650 light-years (or 200 parsecs) from the Sun.

Orion's Belt is one of the most recognizable asterisms in the night sky and easily one of the most easily identifiable parts of the constellation Orion consisting of three bright stars nearly equally spaced in a line in our night sky as seen from our vantage point here on Earth. Although they appear close to each other in the night sky, they are at varying distances some of the farthest Orion stars from our Solar System and each other.

Alnitak (or Zeta Orionis), the easternmost star in Orion's Belt, is a triple star system approximately 1,260 light-years (or 486 parsecs) from our Solar System. The primary star, Alnitak Aa, is a hot blue supergiant and the brightest Class O star in our night sky. It has two companion stars: Ab and B. It's the fifth brightest star in Orion and the 31st brightest star in the night sky.

Alnilam (or Epsilon Orionis), the central star in Orion's Belt, is a massive blue supergiant around 1,344 light-years (or 412 parsecs) making it the farthest Orion star from our Solar System. Its the brightest of the three stars in Orion's Belt and the fourth-brightest star in the Orion constellation. Alnilam is also the 29th-brightest star in our night sky and about 40 times the mass of our own Sun.

Mintaka (or Delta Orionis), the westernmost star, is located about 1,240 light-years (or 380 parsecs) from our Solar System and is closest to the celestial equator. It is a multiple-star system composed of three spectroscopic components of about six stars, the main one being a Class O blue supergiant star similar to Alnitak Aa.

The stars of Orion's Belt are several times more massive than the sun and thousands of times brighter. Combined, the ten stars of these three systems possess a luminosity approximately 970,000 times that of our own Sun!

 

The size of the Orion Belt stars compared to our own Sun.

One more fun fact for all you amateur stargazers out there is that you can actually use these stars of Orion as a guide to locating other stars and nearby constellations. Please be sure to check out my previous blog post on the subject HERE.

Night Sky Photography -- 03-06-2022 -- The Constellations And Major Stars Of The Winter Circle In One Shot!

Good evening fellow stargazers!

Happy March everyone! The month that sees the winter season give way to the renewal of the spring equinox on Sunday, March 20th.

In the evening and night sky dome the six main constellations that make up the Winter Circle (or Winter Hexagon) will continue to be visible in clear skies even as they continue to move west following the setting sun as winter gives way to spring in the Northern Hemisphere.

As I've mentioned in previous Night Sky Photography posts on this blog, the Winter Circle consists of seven bright stars in six separate constellations:

Pollux and Castor in the Constellation Gemini the Twins
Procyon in the the Constellation Canis Minor the Lesser Dog
Sirius in the Constellation Canis Major the Greater Dog
Rigel in the Constellation Orion the Hunter
Aldebaran in the Constellation Taurus the Bull
Capella in the Constellation Auriga the Charioteer

With the exception of the star Castor in the Constellation Gemini, the Winter Circle stars are all 1st-magnitude with Sirius (the Dog Star) being among the brightest stars in our sky. Castor is slightly fainter 2nd magnitude star, though still very bright and visible next to its companion twin, Pollux.

This evening, I was able to capture virtually all the major stars of five of the six constellations of the Winter Circle with one exception. Though I was able to capture the bright star Sirius, the Constellation Canis Major unfortunately would not completely fit in the frame from the only angle I was able to pick up all the stars of the other constellations with.

The following are the photos I was able to take, the first of the major stars in the Winter Circle (outlined in blue) and then the second photos outlining the constellations themselves in white with the Winter Triangle (outlined in red) inside the Winter Circle itself.

Oh and for those of y'all wondering, that small orb-like thing on the bottom right of the photographs is NOT a UFO! It's just the road light that blew out in my front yard recently that the folks at the power company has yet to fix. Thankfully the blown bulb allows for both some foreground scale, and for less light pollution where I didn't have to drive a few miles away to some open field for the shot, so no complaints there at all.

The Winter Circle will still remain fully visible throughout the rest of the month of March with our lovely moon passing between Aldebaran and the Pleiades Star Cluster this week on Tuesday, March 8th and Luna beginning her march through the Winter Circle phasing to First Quarter beauty on Thursday, March 10th. Y'all be sure to check that out -- God and clear skies willing that is.

Night Sky Photography -- 01-12-2022 -- The Moon, Pleiades, & Hyades Star Clusters

Good evening, y'all!

Well, my first night sky photographic offering of 2022 are ones I think y'all will thoroughly enjoy. They involve two beautiful star clusters: the Pleiades and the Hyades.

This evening several hours after sunset the Waxing Gibbous Moon could be seen with the faint Pleiades Star Cluster in the night sky.

The Pleiades (Seven Sisters) could be seen just outside of Luna's glare. I took one photo using the trunk of a tree to block out the Moon's glare and get what turned out to be a really beautiful shot of all of the major stars in the star cluster. The Pleiades are about 444 light-years away from our Sun.

My second photo is a wide shot with the tree in the foreground of the moon and Pleiades with three of the major stars of the Winter Hexagon asterism: Aldebaran, Rigel, and bright Sirius just visible in the corner of the photograph. Rigel, along with the stars Betelgeuse and Bellatrix are the three brightest in that order that make up the Constellation Orion The Hunter outlined in the photo.

The second star cluster visible with Luna in the night sky tonight is the V-shaped Hyades cluster, which makes up the "head" of the Constellation Taurus The Bull. The brightest star is Aldebaran: the Eye of the Bull. This cluster is easy to locate using the Orion's Belt asterism as a line to Aldebaran.

Although not a true member of the Hyades star cluster, the bright reddish star is a great guide to this cluster. Aldebaran is only about 65 light-years distant. The Hyades themselves are about 153 light-years distant, with Aldebaran in the light of sight between the cluster and our Sun.

In the Northern Hemisphere, both the Pleiades and the Hyades star clusters are best seen in the evening sky from around January to April. Both star clusters are made up of many more fainter stars that are not visible to the naked eye (especially closer to city lights) but can be seen with the aid of a telescope, binoculars, or a really good camera lens.

And finally, my last offering to start out 2022 is a pretty beautiful shot of our dear Luna in her Waxing Gibbous Phase.

Well folks, I hope y'all enjoyed my offerings for the evening. Tomorrow evening, in the Northern Hemisphere, the moon's path with take it close to Aldebaran. Be sure to check it out -- clear skies permitting, of course.

Until next time have a wonderful evening and be sure to keep your eyes to the night skies, y'all hear!

Night Sky Photography -- 09-28-2021 -- The Constellations Taurus The Bull & Auriga The Charioteer

Hello fellow night sky watchers!

Well y'all I had to stay up extra late this evening (about two hours after midnight) to capture several really good shots of the brightest stars of the Constellations Auriga The Charioteer and Taurus The Bull rising in the east with the beautiful Last Quarter Moon.

In the first photo, using the moon as a guide, you can see the constellation's brightest stars Capella and Aldebaran, along with the bright star, Elnath, which connects both constellations together in the sky dome.

Capella is the brightest star in the constellation Auriga -- the sixth-brightest star in the night sky -- and the third-brightest in the northern celestial hemisphere after Arcturus and Vega.

Capella is the Latin word for nanny goat, and this bright star is often called the Goat Star. The mythological charioteer character, Auriga, is often depicted in mythology holding a female goat and her kids, along with the reins of a chariot.

Relatively close to us at about 42.9 light-years from the Sun, Capella appears to the naked eye to be a single star. In fact that bright point of light is made up of four separate stars, two of which (Capella Aa and Capella Ab) are a binary pair of large type-G yellow giant stars estimated to be anywhere from 10 to 12 times the size of the Sun. The other pair, Capella H and Capella L, are smaller red dwarf stars.

Aldebaran, the Eye of the Bull, is the brightest star in the Constellation Taurus The Bull and generally the fourteenth-brightest star in the night sky. The red giant is 65 light-years from the Sun and measures about 44 times the size of the Sun.

The traditional name Aldebaran derives from the Arabic term al Dabaran meaning "the follower" because it seems to follow the Seven Sisters (Pleiades) in the night sky.

Connecting both constellations is the bright star Elnath (or Beta Tauri). The second-brightest star in the Constellation Taurus the Bull, the B7 giant star is approximately 134 light-years away from the Sun. Elnath is estimated to be about 4.5 times the size of our Sun. The name Elnath comes from the Arabic word meaning "the butting" (or the Bull's horns).

In my second photo, I outlined the constellations as they are depicted. You can also see the Pleiades Star Cluster just above Taurus, which appear as a little dipper of five small, bright stars (two of them were not visible in the shot). You can also see the bright star, Rigel, just above the treetops on the bottom right.

Rigel (Beta Orionis) is a blue supergiant star and the second brightest star of Constellation Orion The Hunter, approximately 860 light-years from Earth. Like Capella, Rigel is a star system made up of at least four stars that appear as a single blue-white point of light to the naked eye.

Together, these bright points of light make up part of the Winter Hexagon (or Winter Circle) asterism that also includes the stars Pollux, Procyon, and Sirius. Capella is the northern most of these stars in the Winter Circle -- highlighted in blue here in my third and final photo of the evening.

Well folks, this concludes my presentation for the evening, my first one of the 2021 autumn season. Hopefully I will be able to bring you more soon, clear skies permitting. Until then, have a wonderful evening and be sure to keep your eyes to the night skies, y'all!

Night Sky Photography -- 04-25-2021 -- The Whole Winter Hexagon In One Photograph!

Good evening everyone!

This evening I went out to the local baseball field -- the biggest open view of the sky close to where I live -- to try and get a photo of Mercury and Venus low in the west toward the sunset.

Unfortunately, both planets were far too low over the horizon for me to get a good shot of them. But it wasn't a total loss. I was able to finally capture the major stars of the Winter Hexagon (Circle) asterism and Mars in a single photo.

The best way to find the Winter Hexagon is to look for the Constellation Orion The Hunter -- the only constellation that is completely encircled in the asterism. Orion is quite helpful in locating half of the stars in the Winter Circle.

The bright star Rigel, one of the feet of Orion, is a starting point. Use either Rigel, or Orion's Belt, in a line to the bright star Aldebaran in the Constellation Taurus The Bull. You can also use Orion's Belt to point out Sirius, the brightest star in both the Constellation Canis Major (The Greater Dog) and the Winter Hexagon.

The star that makes up Orion's right shoulder, Betelgeuse, is one third of the second asterism, The Winter Triangle, along with Sirius and Procyon in the Constellation Canis Minor (The Lesser Dog).

Once you locate these its easy to find the rest of the bright stars in the Winter Hexagon: Pollux, Castor, and Capella.

Mars will continue to remain a part of the Winter Hexagon till at least June 12th of this year when it joins the twin stars Pollux and Castor. The Red Planet will continue to grow fainter as it moves farther away in its orbit from Earth.

Well everyone I hope y'all enjoyed my final night sky photographic offering of this month. Next month promises to have some really exciting moments for night sky observers -- including a Lunar Eclipse on the night of May 25-26th! Hopefully we will be blessed with clear skies for that here in South Carolina.

Until next time have a wonderful Dixie evening and y'all be sure to keep your eyes to the night skies, y'all hear!

Interesting Facts About The Constellation Orion

 

Greetings fellow night sky fans!

Tonight I thought I'd share something pretty interesting tidbits about the Constellation Orion for y'all.

Named by Western cultures for the hunter in Greek mythology, Orion is probably the most prominent constellation easily recognizable in our sky dome. In the Northern Hemisphere, Orion is most visible in the evening sky from January to March during the winter months. It lies on the celestial equator and is one of the brightest and best known constellations in the night sky. 

Orion is largely made up of eight prominent stars.

The  B-type blue super giant star, Rigel (Beta Orionis) and the red giant star Betelgeuse (Alpha Orionis) are the two brightest stars of the constellation respectively. Rigel is the sixth-brightest star in the night sky as seen from Earth. Rigel’s distance is estimated to be around 773 light-years, while the distance to Betelgeuse is estimated to be about 724 light-years away.

The this constellation's most distinctive feature are the three stars that make up the Orion's Belt asterism: Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis), and Mintaka (Delta Orionis). The names of the three stars come from Arabic word Alnilam which means "string of pearls" Looking for Orion's Belt in the night sky is the easiest way to locate Orion.

The other prominent stars that make up Orion are: Bellatrix (Gamma Orionis), Saiph (Kappa Orionis), and Meissa  (Lambda Orionis).

Eight major stars make up the Constellation Orion The Hunter.
The largest of these is Rigel, followed by Betelgeuse, Saiph, Bellatrix, Meissa, and the three stars:
Alnitak, Alnilam, and Mintaka that make up the "Orion's Belt" asterism.

 

In Greek mythology and astrology, Orion the hunter is accompanied by his hunting dogs: the constellations Canis Major and Canis Minor, and is hunting Taurus the Bull.

One can easily find the major stars of each of these three constellation by using Orion as a starting point.

Using Orion's Belt as a straight line an amateur stargazer can easily locate the "dog star" Sirius, the brightest star in the night sky as seen from Earth, to the bottom left.

Going the opposite way, using the upper part of Orion's Belt one can make a line to Aldebaran, the "Eye of the Bull" and the brightest star in the constellation Taurus.

Finally using Betelgeuse as a starting point one can make a straight line to the star Procyon, the brighter of the two stars that make up the "lesser dog" Canis Minor.

Picture here with the Constellation Orion are Taurus The Bull and the two dogs Canis Major
and Canis Minor.
Using a straight line with Orion's Belt as a starting point, finding the bright stars Sirius and Aldebaran are easy.
Procyon can be found using a straight line from Betelgeuse on Orion's left shoulder.

Betelgeuse, along with the stars Procyon and Sirius, also make up the Winter Triangle asterism. These three stars are three of the ten brightest objects, as viewed from Earth, outside the Solar System.

In addition, Orion itself is also a part of and largely surrounded by an even larger asterism, the Winter Circle (or Winter Hexagon) with Orion's brightest star, Rigel, making up one of its six major stars.
 

The major stars of the Winter Triangle and Winter Circle (Winter Hexagon) as seen in the night sky
with the constellation Orion in the winter months in the Northern Hemisphere.

 

The constellation contains several interesting nebulae: the Orion Nebula (Messier 42), De Mairan’s Nebula (Messier 43), the NGC 2068 Nebula (Messier 78), and the famous Horsehead Nebula (Barnard 33) among others. In addition seven stars in the constellation Orion possess planetary bodies.

In the winter months one can find Orion by looking to the east an hour after sunset. The easiest way to spot it is to find Orion's Belt.

Well folks, I hope y'all enjoyed this presentation. Let me know in the comments section below.