NGC 2419: A very, very distant globular cluster

[John]

For some reason that I can't quite explain, even to myself, I decided to have a go at finding the distant and rather faint globular cluster NGC 2419 (Caldwell 25) tonight armed with just the 10cm aperture of my Takahashi FC100-DL. I guess the name used on some charts of "Intergalactic Tramp" has a romantic attraction to it. Lynx and Gemini are also quite close to the zenith tonight which would help pick this magnitude 9 or 10 (depends on the reference) object out of the background sky.

It turned out to be quite a challenge as a couple of references that I consulted warned be that it would be with a 10cm aperture scope. I'd definitely now lean towards magnitude 10 !

Although in the constellation Lynx, Pollux and Castor in Gemini are the best initial pointers to the patch of sky where NGC 2419 resides. Then refer to 3 stars in Auriga for the next steps - 65, 63 and 66 loop you around to be close to the right spot. Sliding back over the border into Lynx for the final step. Here is a star chart to better explain the location:

This faint and far off cluster is conveniently located next to a couple of close stars that are visible even in my 30mm finder and the three form a line with the globular glowing very faintly (through the scope but NOT in the finder) as the 3rd object. Tonight, despite being very high in a sky with a NELM of around mag 5, was on the margins of being an averted vision object. When I boosted the magnification to 120x or so I could just make out a small fuzzy patch of light with direct vision.

I have seen this object with my 12 inch dobsonian a few years back and it was somewhat easier of course but I was being subborn about getting it with the 100mm Tak tonight

This is actually a massive and highly luminous globular cluster with 1 million member stars spread across 400 light years of space. It is though around 270,000 light years from us. That is more than 10x as far away as the famous Messier 13 globular cluster in Hercules and 100,000 light years further out from the galactic centre the Magellanic Clouds.  This illustrates the distance of this object well:

Recent research seems to indicate that the nickname "Intergalactic Tramp" (coined by Harlow Shapley I believe) is not quite accurate as, despite it's remoteness, NGC 2419 is still under the influence of our galaxy. It will however take around 3 billion years to complete one orbit of the galactic centre.

Observed visually with a small scope, or even with a larger one, this is not a spectacular object however it is one which provides a good challenge to see and, when you find out a little more about it and realise what you are observing, it takes on a special fascination. This sketch by Phil Harrington was the view from a dark site with a 102mm refractor. My view was not quite as good but not far off:

When the Hubble Space Telescope imaged it, NGC 2419 did reveal its full majesty

 

I'm very pleased to have tracked this one down tonight with my little refractor. Very satisfying and I've learned a lot as I've researched it further as well

 

[ShrewView]

Very interesting. Thanks.

A tough one. Caught it last year, but very faint even in an 8 inch newt. 

[Ships and Stars]

Amazing to realise objects that far away are still affected by gravity from our galaxy. Some of the Caldwell objects are pretty challenging I think. Very interesting post, thank you John.

Edited March 26, 2020 by Ships and Stars

[Littleguy80]

Nice write up, John. I remember seeing this on one of my early dark site trips with my 130mm newt. Took me at least an hour to find. I kept passing over it because it was so faint. It’s a lot easier in the 10” dob but still a great one to hunt down. I think this is often referred to as the Intergalactic Wanderer. Pretty sure Nick @cotterless45 referred to it as that in a report at least. 

[cotterless45]

Yep, on my favourites list. We had a faint sparkling at SGL which was very much enjoyed by those observing when the distance and history were given. Wonderfully informative post John. Always worth finding this fish hook of stars and watching for a sparkle at the end,

Nick.

Edited March 26, 2020 by cotterless45

[jock1958]

Thanks John a very interesting post, must admit I didn’t know the positions of the Large & Small MC’s in relation to our own galaxy.

Clear skies forecast down here tonight so will give it a go, though not confident I will see anything through my Tak 100! 

[wookie1965]

I have seen it once when I had my 8" at a meet that I just cannot remember where, I was in a either a yurt or cabin over a hill Quite a few people turned up, one being Nick who told me go for this and we saw it I doubt my 4" or 5" would catch it now from home.

[oldfruit]

Like yourself, I managed to track this down with the 12 inch dob a few years ago, an unimpressive object until you factor in the distance. A great achievement to track it down with a 10 cm scope.

[Whistlin Bob]

Thanks for this post- it went into my list for last night and I had a fun fifteen minutes locating and then observing it.

In a 14" in Bortle 5 with moderate transparency it was just visible with direct vision and gave away some shape with av and scope wobbling. 

Really nice target 😀

[estwing]

Super report John. 

[Size9Hex]

Smashing post. I’ve seen it called the wanderer rather than tramp. Caught it a few years ago in the 10" and there wasn’t much to see. Cracking effort to pick it up with 10cm! That orbital period of 3 billion years is amazing.

[Jiggy 67]

SkySafari has it called Wanderer as well. Added to my list for the next dark night. I love globs!! Even the fuzzy ones!!

[Captain Scarlet]

I saw this tonight, almost by accident! I didn't star hop, I used goto and typed in NGC 2419 as that was in my mind (from this post), but somehow in my head I thought I'd asked for Tegmine. When I looked through the eyepiece and hunted around a bit, I suddenly spotted two stars in a line and a faint blob just beyond and recognized the arrangement from the sketch and realised my mistake! I did spend some time staring at it, in awe of its distance 1/10th the way to Andromeda out in the middle of nowhere. Actually noticing it wasn't difficult, I was using a 12" and my darkness tonight was 21.7.

Quite pleased, and thanks for this thread without which who knows when I'd have got around to it, Magnus

[Ciaran Meier]

Thanks for the effort putting this together,  a "mini TED".  No luck yet spotting it yet in my 8 inch newt but will persevere. 

[Nyctimene]

Spotted the Intergalactic Wanderer this morning with the 5.1" Heritage Flextube. Nick's (cotterless 45) description was spot on: "a fish hook of stars and a sparkle at the end". Under 5.2 mag skies not a sparkle, but a faint glow, about 2.5 arc min diameter, round, constantly seen with AV and mags of about 130-150x (Seben Zoom+2.25x Barlow), directly perceived for about 50% of observing time. Not that difficult - experience helps!

[pjsmith_6198]

Thanks for the excellent write up John.   Lots of interesting information there.   It must have taken awhile to put together.   NGC 2419 is indeed challenging.   It took me 3 observing sessions to be able to see it.  Only when I saw a photo of it in the DSO-Browser did I see it's location  in the EP FOV.   The two bright field stars pointing to it.   Previously I was focusing  on the faint star above it on the sketch above.  There was something there but it was popping in and out of visibility.  I assumed that was NGC 2419 but under higher magnification it looked stellar.   It was right in front of me but I was looking at the wrong target.   Once I knew the 2 stars where pointing to it, I was finally able to see it.

 

Phil