Many constellations have one very special deep sky object within their borders, something so famous that when you say, read, or hear that constellation’s name you instantly think of it, like an astronomical word-association game.
Orion? The Orion Nebula! Andromeda? The Andromeda Galaxy, of course! Lyra? Easy – the Ring Nebula. And Perseus? Has to be The Double Cluster, right?
Not all constellations have such a claim to fame. There are many constellations that are not homes to a particularly striking or beautiful nebula, sparkly star cluster or swirly galaxy, and so they are often overlooked; like impatient tourists, observers drift through or past them on their way to more exciting destinations. These are the shy constellations: the ones that hide in a corner of the living room during a star party, concealed behind a potted plant or next to the fish tank, talking to the dog while the other, more confident constellations dance together or hang out in the kitchen, laughing and joking while they eat all the pizza and nibbles.
But just because a constellation doesn’t have a celebrity feature in it, that doesn’t mean there’s nothing to see in it. Every constellation has something within its borders worth tracking down, if you just look hard enough. Consider these Shy Five…
Cetus: The Skull Nebula (NGC 246)
The Skull Nebula, NGC 246, is a planetary nebula roughly 1,600 light-years from Earth. It is also known by some observers as the Pac-Man Nebula because of the similarity of its shape to the greedy gobbling video game character; just don’t confuse NGC 246 with the much bigger and much brighter Rosette Nebula, NGC 2337, which is also known as “The Skull” by some.
With a magnitude of 10.9, NGC 246 is one of the faintest planetaries in the sky. Although it can be seen with smaller instruments from dark-sky sites, this nebula really needs a 6” telescope or larger to be seen properly, as a disk-shaped, slightly mottled haze with foreground stars scattered across it.
Aries: NGC 772
Let’s be honest: There’s not much to see in Aries. It’s the sky equivalent of a remote country town you drive past on your way to somewhere more interesting. But if you park in it and wander around, you will come across NGC 772, a pretty, 10th-magnitude spiral galaxy approximately 130 million light-years away from us.
With a diameter of approximately 250,000 light-years, NGC 772 is larger than our own Milky Way. Long-exposure images show the galaxy’s spiral arms are warped and distorted by nearby dwarf galaxies, but they are so faint visually that you’ll only see its bright core if you’re using a large aperture instrument.
Camelopardalis: IC 342
One of the very shyest of the constellations, Camelopardalis the Giraffe is rather lacking in deep sky objects, although many observers are drawn to the galaxy NGC 2403 lying near the Giraffe’s mouth. But halfway along the giraffe’s back is another deep sky object that is shamefully overlooked and neglected by observers…
IC 342 is a magnitude 8.6 spiral galaxy that is relatively close to us, somewhere between 7 million and 11 million light-years away. It can be seen with binoculars as a surprisingly large hazy patch, very similar to more famous M33, and telescopes easily pick out its tightly wound spiral arms. So why is it not better known, and why is it referred to as “The Hidden Galaxy”? Because, unfortunately, it lies behind a very dusty part of our own Milky Way, so our view of it is rather ruined. If it was elsewhere in the sky, IC 342 would be a lovely sight, easily visible to the naked eye.
Lynx: The Intergalactic Wanderer (NGC 2419)
While lynx are beautiful creatures in real life, the constellation Lynx, sandwiched between the Great Bear and The Twins, is an unremarkable spray of faint stars. However, it contains something definitely worth hunting down. Globular cluster NGC 2419 was discovered by William Herschel on the last day of 1788. Overshadowed by brighter, more famous globulars such as M13 and Omega Centauri, NGC 2419 is a respectable magnitude 9, meaning it can be seen easily in small telescopes as a smoky spot.
Globular clusters famously orbit galaxies like moths fluttering around streetlights, but it was once thought that NGC 2419 didn’t orbit the Milky Way, and was some sort of rogue cluster. It was even nicknamed “The Intergalactic Wanderer.” We now know that it does belong to our galaxy, sometimes passing beyond the Magellanic Clouds during its 3-billion-year-long orbit.
Sagitta: M71
If we could somehow switch on the artwork of the sky for real, like we can when using a phone app or computer program, we would see an arrow lying at the paws of Vulpecula the Fox. This is Sagitta the Arrow, and its main purpose seems to be to guide observers to the famous Dumbbell Nebula, M27, which lies just north of its sharp point. But Sagitta also contains an overlooked Messier object: Messier 71, a globular cluster 13,000 light-years away. M71 is a loose globular cluster, meaning its stars are less densely packed than those in more well-known globulars. In fact, it probably looks more like M44 than M13, and a dark notch out of its western side is very obvious under high magnification.
These are just five of the objects that are overlooked in the sky. There are many, many more. So the next time you head out on a clear night and point your telescope towards the stars, don’t swing it straight to your favorite objects, the brash ones which shout “Look at me!” every time you venture outside. They’re not going anywhere. Instead, give the shy deep sky objects a chance to tell you their stories for a change.
