By Jake Riley, SR Senior Editor

Fun Facts

1. Gemini means ‘twins’ in Latin
2. The brightest star of Gemini, Pollux, is the closest giant star to Earth
3. The second brightest, Castor isn’t actually a single star, but a sextuple star system
4. Of the six stars that make up Castor, two are three times bigger than our Sun
5. Every December, a meteor shower—Geminids—occurs within Gemini’s borders

An overview

The constellation of Gemini makes up two almost straight lines, with said lines connecting at the top and diverging at the bottom. The constellation consists of 17 main stars, with the two brightest, Pollux and Castor, denoted as the heads of the twins. The former is nine times bigger than our sun and about double its mass, while the latter is actually a six-star system with its primary star having a radius and mass twice and thrice that of our sun.

It is one of the 12 Greek Zodiac constellations, though the Egyptians depict the very same constellation as twin goats rather than twin humans, and the Arabians depicting them as twin peacocks. It is visible in all of the Northern hemisphere and most of the Southern hemisphere, from winter to spring in the former and only in the summer months of the latter.

The myth

In Greek mythology, there was a set of twin brothers named Castor and Pollux. They were born from the same mother, Queen Leda of Sparta, but apparently had different fathers. Castor was fathered by the queen’s husband, the King of Sparta, while Pollux was the son of Zeus, who had ravished the Spartan Queen disguised as a swan.

Also, the twins were not born from orthodox childbirth, but had hatched from an egg along with two sisters, Clytemnestra and Helen of Troy. As the twins grew older, they formed a close bond with one another, and soon became known as a single entity, the Dioscuri.

However, in another land lived another related set of twin brothers, who—over time—saw the Dioscuri as their rivals. Both pairs of twins were involved in the voyage of Jason and the Argonauts, and briefly entertained a truce between them, though this didn’t last for long.

The mortal Castor was eventually killed by the other twin pair. Taking pity on Pollux, Zeus decided to reunite the twin brothers by placing both of them amongst the stars, and hence the Gemini constellation was birthed.

The constellation

The Constellation of Gemini is situated in the northern sky’s second quadrant, and is visible between latitudes -60 to +90 degrees. It lies between Cancer and Taurus, neighboring Orion, and is the 30th largest constellation in the Earth’s night sky.

Of the 17 main stars it consists, there exists nine celestial bodies of note: Pollux, the brightest star of Gemini and the 17th brightest star in the Earth’s night sky; Castor, the second brightest star of Gemini which is a six-star system; Wasat, which is a three-star system; Melbuda, a supergiant star with surface temperatures matching our sun; Mebsuta, a yellowish-orange supergiant that has twenty times our sun’s mass; Alzirr, a yellow-white star, Alhena, a white star, Tejar Posterior, a red giant 2,500 times more luminous than our sun; and Propus, a three-star system also referred to as Tejar Prior or Eta Geminorum.

Want to learn about other constellations aside from Gemini? Find out more about Cancer or Leo. Alternatively, you can simply click here for a full list of constellations.

Frequently Asked Questions

Can I really name a star?

Yes, you can! Each order is unique to the Star Register and is recorded in the official Official register of Stars. We are one of the few legitimate Registries using advanced mapping software to assign your order.

What happens when I place my order:

Place your order on our order page and one of our experienced employees will handle everything else for you, this includes:
-Preparing relevant paperwork and electronic transmission of all necessary data to the Star register Database.
-Receipt of the response with the unique coordinates of your star
-Preparation of the star chart with the coordinates
-Preparation of the certificate and the gift Kit.

What's the difference between your different products:

We currently offer three products: (1) Deluxe (2) Supernova and (3) Twin. Each of this has it's own benefits and they can be compared on our homepage comparison chart.

How does the star chart work?

You can use the coordinates listed on your star chart to locate the star in the night sky or by searching our Official register of Stars which shows you a real photo of the star in the night sky.

Can I choose the constellation myself?

Yes, this is possible on the order form.

I can't open my order:

As our orders are digitally delivered, you can either open the kit in your browser or through Adobe Reader.

Is my order unique?

Yes. Every star coordinate is only allocated once, to a unique registration.

Where is my gift pack?

If you haven’t received the digital star pack by email within 24 hours please contact

How long is the delivery time?

We deliver by PDF within 24 hours via email. If you have not received your certificate within that time, please email

Is the star visible?

Yes, the easiest way to find the star is through the Official register of Stars. By entering the name it is easy to view the star in the night sky. However, it is also possible to find the location of the star using a telescope.

I am looking for general information about the product (cost, shipping method, payment method).

Please see our gift kit page.

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Can i have the details of my certificate changed?

Once we send the gift kit pack we aren't able to change it.