The Intergalactic Wanderer

NGC 2419 photo courtesy of Mike RichmannAs I discussed in an earlier story, globular clusters hold up well when viewed from washed-out skies. In that story I highlighted the biggest and brightest globulars. Today I want to discuss a globular cluster that is neither big nor bright, but is nevertheless very interesting: NGC 2419, the so-called Intergalactic Wanderer. It got its name because it is so far from the galactic center (300,000 light years, farther than the Magellanic Clouds and well beyond the “halo” containing most globular clusters) that it was long believed to wandering through space independently. We now know that NGC 2419 is indeed gravitationally bound to our galaxy, taking about 3 billion years to complete an orbit. (Photo courtesy of Mike Richmann)

NGC 2419 is a large, intrinsically bright globular cluster, comparable to Omega Centauri. But its great distance makes NGC 2419 rather faint and small, at magnitude 10.4 and less than 4 arc min across. It is somewhat challenging to see in urban skies, harder than its official magnitude suggests. In my experience you’ll need at least a 6 inch (150 mm) aperture and great transparency to see NGC 2419 under light polluted skies. If the transparency isn’t very good or if NGC 2419 isn’t close to zenith, it can be hard to see even in my 10 inch Dob. But seeing this unusual globular cluster is worth the effort and here is some information for you if want to take up the challenge.

You can find NGC 2419 on most major star atlases (e.g., Sky and Telescope's Pocket Sky Atlas, p. 23) and you can star hop to NGC 2419 quite easily from Castor (α Geminorum). There is a 7.3 magnitude star (shown on the Pocket Sky Atlas) about 4 arc minutes due west of NGC 2419. Another several arc minutes further west there is a wide double star (magnitudes 8 and 11). This combination of stars (seen in the photograph above and also shown below in a chart produced using Cartes du Ciel) is quite distinctive and helps you make sure you are looking in the right place.

NGC 2419 finder chart produced with Cartes du Ciel

As I mentioned, NGC 2419 is rather hard to see in light-polluted skies. The photograph below is Mike Richmann's photo modified to better represent what you can expect to see. If you make it out to a dark-sky location, you'll find NGC 2419 is actually quite impressive, but don't expect to resolve it, as its brightest stars are magnitude 17.

NGC 2419 as it might appear visually under washed-out skies



NGC 2419

This is a fun globbie to hunt down. I really like your write up and descriptions.

I have not tried it from my backyard and you have encouraged me to do so!