Facts About the Gemini Constellation – And How to Find It

Like many other constellations, Gemini, or the twins, is steeply rooted in ancient Greek mythology. While other tales may be heavily debated, the story behind the Gemini constellation is straightforward.

Whether you were born a Gemini or are just interested in this constellation, we’re going to share the story behind this myth and how to locate the Gemini constellation.

What is the Story Behind the Gemini Constellation?

The twins that are represented in Gemini are Castor and Pollux. Although they have different fathers, they share the same mother: Leda. Tyndarus is Castor’s father and also the husband of Leda. Pollux’s father just so happens to be Zeus. Because Pollux’s father is a god, he is immortal. Castor is a mere mortal.

The twins were curious and adventurous. Each had their own strengths. Pollux was known for his strength, and Castor known as an excellent horseman. Castor and Pollux had a sister – someone you probably know – Helen of Troy. The twins fought in the Trojan War together, and they were also together on the Golden Fleece quest.

To say that Castor and Pollux were close is an understatement. Naturally, when Castor, being a mortal, finally dies, Pollux is left distraught. He turns to his father, Zeus, for help.

Zeus decides to immortalize Castor, so he and his brother can live together forever as the Gemini constellation.

What’s unique about the Gemini constellation is that the Greeks weren’t the only ones to call these two bright stars ”the twins.” Other ancient civilizations also had their own tales about these brother stars.

• Egypt astrology identified this constellation as twin goats.
• Arabian astrology called it the twin peacocks.
• Gemini has been associated with Romulus and Remus, the legendary founders of Rome.

By Till Credner - Own work: AlltheSky.com

What Does the Gemini Constellation Look Like?

The Gemini constellation is easy to spot. Most people say it looks like two bright stars, although one is brighter than the other.

Castor is white in color and not quite as bright as Pollux. Pollux’s color is more golden than white.

Castor and Pollux represent the heads of the twins. The entire shape of the constellation looks like two human stick figures holding hands.

When viewed from the southern hemisphere, the shape may look a little different. The twins may look like they’re standing on their heads.

How Many Stars are in the Gemini Constellation?

Gemini has 85 visible stars, but the two brightest ones are Castor and Pollux.

• Castor is 52 light-years away.
• Pollux is a giant star that is 34 light-years away.

Other notable stars include:

• Alhena: 105 light-years away. Alhena is the third brightest star in the constellation and a blue evolving star. It has a magnitude of 1.9, making it 123 times brighter than the sun. The star has an estimated surface temperature of 9,260K.
• Wasat: 59 light-years away. Wasat is a three-star system that consists of a subgiant star, a K-type star and a third star that has yet to be established. It has a 3.53 visual magnitude and a surface temperature of 6,900K.
• Mebusta: 900 light-years away. Mebusta is a supergiant star that has a visual magnitude of 3.06. This giant star has 14,000% of our sun’s radius and 1,920% of is mass. It’s more than 8,000 times brighter than our sun.
• Mekbuda: 1,200 light-years away. Mekbuda has a visual magnitude of 3.93, although its brightness can vary. This star has 770% our sun’s mass and 6,524% its radius. It’s also more than 2,000 times brighter than the sun.
• Propus: 380 light-years away. Propus, which has three stars in its system, has a visual magnitude of 3.15. Its primary star is nearly 13,000 times brighter than the sun.

Pollux has at least one giant planet orbiting it, while Castor has a few companion stars.

The Gemini constellation has a few other notable things:

• The neutron star Geminga
• Medusa Nebula
• Eskimo Nebula
• Messier 35 (M35)

Where is the Gemini Constellation?

Gemini is best viewed in January, February and March. During these months, the stars in this constellation are up in the East at night. You can catch a glimpse of the twins until about May or June. As we shift towards summer, Gemini descends low into the West and disappears with the sunset.

Gemini is the 30th largest constellation in the sky, and it spans 514 square degrees.

How to Find the Gemini Constellation

Even if you’re new to stargazing, Gemini is relatively easy to spot in the night sky. It’s even easier if you’re in an area free of light pollution and when the moon isn’t full.

You can find Gemini northeast of Orion between Cancer and Taurus. It’s situated in the second quadrant of the northern hemisphere.

The constellation is visible between:

• Latitudes 90 degrees and minus 60 degrees
• Declination: 20 degrees
• Right ascension: 7 hours

Fun Facts About the Gemini Constellation

• Every year in mid-December, Gemini is home to a meteor shower known as Geminids. It’s known as one of the best meteor showers because it’s so bright and moves quickly.
• Geminids are also linked with an asteroid called 3200 Phaethon, which is close to Earth. The asteroid is shedding particles because of a collision from its past. As the Earth orbits the sun every year, it runs into some of these particles, which produce stunning meteor trails.
• In 2006, it was confirmed that Pollux had a massive planet orbiting it. The planet, named Thestias, is 2.3 times the size of Jupiter and has an orbiting period of 590 days.
• The sun, stars and moons can cross through Gemini.
• Nine of Gemini’s stars have planets.
• Gemini was one of 48 ancient constellations listed by Ptolemy, the ancient astronomer, in the 2nd century Almagest.
• Geminids are one of the richest meteor showers. At their peak, around 100 meteors per hour have been recorded.

Conclusion

This nebula looks like Saturn Gemini is an easy-to-spot constellation with a feel-good backstory. Some interesting events happen within these clusters of stars, including spectacular meteor showers. In Gemini, you’ll also find nebulas and M35. It's a fascinating constellation that’s worth exploring.