Skip to main content

Gemini—Pollux and Castor—Stars and Myths

The star cluster in the lower right quadrant of this picture is M35 or Messier35—one of the "messier" space objects.

The star cluster in the lower right quadrant of this picture is M35 or Messier35—one of the "messier" space objects.

Castor and Pollux Stars in Gemini

I’ve always been fascinated by the constellations. I learned about them in detail in middle school, and I still enjoy taking out my star maps to locate them in the sky.

One constellation, Gemini, is particularly interesting to me. I was born right when the sun entered Gemini—supposedly—and it’s an easy-to-identify constellation in the sky.

Gemini is one of the constellations of the zodiac.

The zodiac includes 12 constellations that are located around the ecliptic (basically a celestial sphere) and include Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Capricorn, Sagittarius, Aquarius and Pisces.

Pollux and Castor

A few ancient tales exist about Gemini. Its name means “twins.” Since the dawn of humans, civilizations have given Gemini various “twin” names. Arabs in the Middle East called it Two Peacocks, the Hindus named it Twin Deities, and the ancient Egyptians heralded it as Two Sprouting Plants.

The two brightest stars in Gemini are called Pollux and Castor.

One story says that Pollux and Castor were the twin sons of the Queen of Sparta, named Leda. Jupiter was their father. Jupiter may not have been Castor’s father, though, because Castor was mortal and Pollux was not.

When Castor died in battle, Pollux begged for his brother’s immortality. It was granted, but they both had to move to the sky.

Another tale recounts how the brothers joined the Argonauts, a group of mariners trying to secure the Golden Fleece. Jason, their leader, needed to find the fleece to secure his place on the throne.

Castor had a penchant for horses and Pollux was a brave fighter, often only fighting with his bare hands.

In ancient times, mariners on the sea wanted to honor Leda when they saw a curious glow around the ropes during lightning storms. They called them Ledean Lights.

Gemini Constellation

In January, the constellation Gemini is in the eastern sky by dusk. In June, it’s in the western sky. It’s located in the Northern Hemisphere.

The constellation is characterized by two relatively bright stars. Pollux and Castor are the “heads” and their bodies extend virtually parallel down from them. The northern “feet” are closer to the constellation Taurus and the southern “feet” are nearer to Orion.

If you look closely, you may be able to see showers of meteors around the feet of the constellation in mid-October and around the head in early to mid-December.

The entire constellation of Gemini boasts more than 50 double stars. They can only be seen with a telescope.

The signs and symbols of the Zodiac.

The signs and symbols of the Zodiac.

Gemini Stars

Pollux is brighter than Castor. That wasn’t always the case, though. Castor used to be brighter a long time ago. It’s the largest double star in the northern hemisphere. This double star was the first of its kind for scientists to discover.

Castor is pretty bright, as well. Its magnitude (measure of brightness) is between 1.9 and 2.9. On a scale of 0-5, 0 is considered the brightest object, and 5 is the least bright. It’s about 47 light years away.

Castor as a double-star can be seen with a small telescope, but it’s not visible to the naked eye. The two stars revolve around each other every 420 years.

Pollux is brighter at a magnitude of 1.2, making it the 15th brightest star in the northern sky. It’s located about 31 light years away, but retreating at a rate of 2 miles per second!

Gemini’s stars have a name designation called Geminorum. Castor is α Geminorum; β Geminorum is Pollux.

Sir William Herschel was studying the constellation in 1781 when he saw an unidentified object near the star η Geminorum, also called Propus.

Six months later, he determined that it was a planet—not a comet—and one that was twice as far from the sun as its planetary neighbor, Saturn.

The scientific community finally decided to name this new planet Uranus. Saturn’s mythical father was Uranus.

Near the star δ Geminorum (also called Wasat) is where the planet Pluto was discovered in 1930.

Not visible to the naked eye, but interesting nonetheless is the star cluster M35. It’s located at Castor’s feet, right by 1 Geminorum. Astronomers call it one of the most beautiful objects in the sky.

This is just one constellation of which to study, but is incredibly interesting.

References and Resources

  • Field Book of the Skies. Olcott, William T. G.P. Putnam's Sons, New York: 1954.
  • The Handy Space Answer Book. Engelbert, Philis and Diane Dupuis. Visible Ink Press, MI: 1998.
  • Guide to Stars and Planets. Moore, Sir Patrick. Firefly Books, New York: 2005.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2012 Cynthia Calhoun


Cynthia Calhoun (author) from Western NC on August 12, 2012:

Terrye - haha, I will! I've gotten so much fun feedback from these, I'm already working on the next one! ;D Cheers!

Terrye Toombs from Somewhere between Heaven and Hell without a road map. on August 12, 2012:

CC, great job and hope you will be continuing on with a whole series on the constellations. :)

Cynthia Calhoun (author) from Western NC on July 25, 2012:

Doc Sonic - a fellow Gemini! That's awesome! Thanks for stopping by and for your feedback. They mythology is interesting, no? Thanks again. Cheers!

Glen Nunes from Cape Cod, Massachusetts on July 24, 2012:

Very informative. I'm a Gemini, and I knew a little bit about the constellation, but not so much about the mythology. You did a nice job covering both.

Cynthia Calhoun (author) from Western NC on July 22, 2012:

Docmo - haha, double delights for sure! :D I've got another one I'm just about to finish. Thank you so much for stopping by. I definitely enjoyed writing this. Cheers!

Mohan Kumar from UK on July 22, 2012:

Truly resourceful, filled with fascinating facts and immensely readable, Cyndi. I love astronomy and equally love Greek Mythology so this hub is a 'twin' delight!Voted up , of course!

Cynthia Calhoun (author) from Western NC on July 21, 2012:

Teaches - aw, thank you. Yes, the Greek mythology is fascinating. I think I want to research the others to share. Thanks so much for stopping by at another of my hubs - you are a gem, my friend. :) Hubhugs!

Cynthia Calhoun (author) from Western NC on July 21, 2012:

Dan - hmm, yes, Pollux and Castor can sometimes play coy and "blend in" - but look in the western sky this time of year in the evening and if you can find Orion's belt, look "up" from that for two bright stars. Thank for stopping by. It's always great to see you. Cheers!

Dianna Mendez on July 20, 2012:

This is an amazing hub on arts and science. I used to love reading about the Gemini in Greek mythology. Thanks for the interesting lesson on these constellations. Voted up!

Dan Human from Niagara Falls, NY on July 20, 2012:

Gemini is one of those constellations I always have problems finding. I don't know why, but for some reason it just doesn't stick out to me like some of the others.

Informative Hub!

Cynthia Calhoun (author) from Western NC on July 20, 2012:

Patty - that sounds awesome! My parents fostered my love of studying the constellations by getting me a telescope. I love looking for the various constellations. :) It's definitely so interesting. Thank you so much for stopping by! Cheers!

Patty Kenyon from Ledyard, Connecticut on July 19, 2012:

Very Interesting Information!!! When I was younger, my dad and I would study constellations together. He had nearly every Carl Sagan (hoping I didn't kill the name) book and when the stars were out, we would spend a great deal of time searching for each constellation!! I now try to do that with my own children. Outer space is fascinating !! Thanks for sharing!!

Mary Craig from New York on July 19, 2012:

Great information so nicely done. I've never been into constellations but have a son-in-law who is always pointing out Orion's belt!

I enjoyed reading this one.

Voted up and interesting.

Cynthia Calhoun (author) from Western NC on July 19, 2012:

Hehe, KrisL - too funny! Thank you so much and that reminds me...I should go hop more often. ;) Cheers!

KrisL from S. Florida on July 19, 2012:

Lit Girl: I found it hopping, thought . . . "I have to follow this person," and then saw that you wrote it. What fun!

Cynthia Calhoun (author) from Western NC on July 19, 2012:

KrisL - thank you so much. :) Yeah, I definitely was trying to make it reader-friendly without getting too much into the scientific query. Thanks for stopping by! I appreciate your feedack. Cheers!

Cynthia Calhoun (author) from Western NC on July 19, 2012:

K9 - aw, thanks for comin' by! I sometimes wonder if I have a split personality. Hehe. Just kidding. Thanks for your feedback. Have a wonderful day! Hubhugs. :)

KrisL from S. Florida on July 19, 2012:

A big cut above the average hub . . . really does tell the average reader everything you'd want to know, without getting too technical, and gives resources for learning more.

India Arnold from Northern, California on July 19, 2012:

I really enjoyed learning the variations in ancient stories of Pollux and Castor, (Gemini). My sister is a Gemini, thus, the thoughts about people born under this sign having two built-in personalities... I believe it to be true! ;)

Nice job!


Cynthia Calhoun (author) from Western NC on July 19, 2012:

alocsin - hehe, yes, I like to keep my readers on their toes. Hehe. Cheers!

Cynthia Calhoun (author) from Western NC on July 19, 2012:

Vellur - yes, I'm now curious about the other constellations for sure! Thanks so much for stopping by. I'm so glad you enjoyed the read. :)

Cynthia Calhoun (author) from Western NC on July 19, 2012:

CloudExplorer - the ancients definitely liked studying the sky. Thank you for stopping by! I appreciate your comments and votes and feedback. :) Thanks again!

Cynthia Calhoun (author) from Western NC on July 19, 2012:

Teresa - hehe, now I need to go read your hub about dogs. :D Thank you for your comments. There are lots of Gemini's walking around. Hehe. Hubhugs!

Cynthia Calhoun (author) from Western NC on July 19, 2012:

Ruchira - aw, thanks for stopping by! You're sweet. Your dad was a fellow Gemini? Awesome! :)

Aurelio Locsin from Orange County, CA on July 19, 2012:

Certainly an unexpected hub from you but I love the mix of science and art. Voting this Up and Useful.

Nithya Venkat from Dubai on July 18, 2012:

Interesting and useful. Enjoyed the read. Each consellation has an interesting history associated. LOved this hub and voted up.

Mike Pugh from New York City on July 18, 2012:

Awesome hub on the constellations, and their relation to our astrological signs.

astrology is something really quite unique, and I found it very interesting how the ancient people actually came up with it all, just by studying the sky at night.

Nice hub, well written, and very useful for those who need to know about astrology, voted up and out!

Teresa Coppens from Ontario, Canada on July 18, 2012:

Voted up Cyndi. I just had to read this before I turned in for the night. My youngest son is a Gemini born in mid June. Wonderful job and packed with interesting facts.

Ruchira from United States on July 18, 2012:

A resourceful hub, Cyndi. I am sure you would be proud of the traits and it's constellation. My dad was a gemini.

voted up indeed as interesting.