High in the southern sky just after dark here in early spring is where you can catch a glimpse of the constellation Gemini, the Twins. Located to the east of Orion, and southwest of the pentagon of Auriga, it can be easily spotted by finding the bright “twin” stars of Castor and Pollux which are side by side. In dark enough skies, Gemini will appear as two stick-figures side by side.
Castor is actually a system of 6 different stars, but two or three can be readily seen with a telescope. Pollux is the brighter of the two, but both are bright enough to be seen in moderate light pollution with the naked eye. Together, they form the two heads of Gemini.
Gemini lies opposite of the center of the Milky Way, and doesn’t contain too many deep sky objects. However, there are a few beauties to be seen with binoculars and telescopes for those looking for open star clusters and even some nebulae.
First, we have the M35 open cluster. It can be found to the right of the star that makes up the bottom right foot of Gemini. It can be seen with the naked eye on a dark night. M35 is roughly the size of a full moon, is 11 light years across and lies around 2,800 from Earth. M35 makes a good target for any level of skywatching, provided there is a dark enough sky if you’re trying to spot it with your naked eyes.
Located in the same field of view as M35 is the much smaller open cluster NGC-2158. Located around 11,000 light years away, it is more dim than M35. Eagle-eyed skywatchers may spot NGC-2158 with binoculars, but telescopes will provide the best view of this open star cluster.
Located due east of the bottom left foot is the NGC-2355 open star cluster. This cluster is just under 6,000 light years away from us, and it is over 1,000 light years above the plane of the Milky Way. A telescope will help reveal the beauty of this star cluster the best.
Next, we have NGC-2392, also known as the Eskimo Nebula, which is a double-shell planetary nebula. It was formed from a star ejecting its outer layers of gas. The Eskimo Nebula resembles the furry hood and face of an eskimo, hence its name. Found due east of the star that forms the left hip of the stick-figured twins, it will appear as a fuzzy star at first. You will need a telescope with around 100x magnification to start to see any of the details of this unique nebula. It can be a little tricky to find, but if you stay with it, you will be rewarded!
Lastly, for our advanced viewers, we have the Medusa Nebula. This nebula can be found due south of the Eskimo Nebula, or east of the left knee star of the left stick figure. Spotting this elusive nebula will require at least an 8-inch telescope and an O-III filter. It spans nearly 4 light years, which is almost the distance from Earth to the next nearest star, Alpha Centauri. The Medusa Nebula is about 1,500 light years away, and is also formed from a star shedding its outer layers. This nebula is not very bright either, so spotting it will be very challenging. The larger the telescope you use, the better chance you will have of finding this elusive, but amazing beauty!
With objects for skywatchers of all skill levels, Gemini is quite the treat! While not as rich in deep sky objects as some constellations, there are some jewels of the cosmos to be found there. From seeing the twin stars of Castor and Pollux, to finding the breathtaking nebulae, be sure to look for Gemini on your next skywatching adventure!
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