PDA

View Full Version : Without a doubt for me is NGC-2419!



Adrian R.
February 19th, 2012, 03:19 PM
During a very cold observing session last night, Ed Neuzil and I are quite sure we actually saw NGC 2419, the Milky-Way's most distant globular cluster in Lynx. In an 8" aperture, the object was barely visible requiring moments of averted vision to see it. In the 20" it was directly visible, but just impossible to resolve. This object's distance from Earth is estimated at nearly 170K LYs..or roughly 10% the distance to M-31... Globs are so cool..in that they represent somewhat of a paradox..with its stars aged more then the universe itself...I find great intrigue while observing them..wondering how this is so...

Marko
February 19th, 2012, 06:23 PM
This is a fun one and thanks for the reminder!

We like to call it by it's colorful common 'fun' sort of name, 'Intergalactic Wanderer'. This is due to it being 600k light year out and sometimes is referred to as the 'Intergalactic Tramp' within a local group of observers here. What I have been calling it lately is due to the squiggle of a line of stars leading up to it's head so I coined the joke name of 'Intergalactic Tadpole' due to the glob being at the head of this 9' bright star leading 'squiggle'. This one is a favorite of a few of our local group of observers, TACos, when they put together YAL (yet another list) called the TAC EyeCandy list some years back.

Below is my observation from an 18" f/3.8 at 389x, NELM 6.5 and 21.5 mag/arcSec sky and like most glob observations the diameter appears FAR smaller than the actual diameter due to unresolved 'glow-stars'. It was this last year that a lot of time was spent on study of globs for the Astronomical League list trying to gain a better understanding of how concentration class correlates to some key things that can be observed on any given glob and the conclusion is visually I can still only really squeeze about 5 classifications out of globs where there really is a range of 12. But Alas, I digress with that being a different yet to be formed thread.

Here is my best observation of 'The Intergalactic Wanderer' itself (not the full tadpole)

NGC 2419 Lyn Glob 07 38 08.5 +38 52 55 10.3 4.6' IntergalacticWanderer: 1' dia Not very concentrated but core does seem a bit brighter. Averted gives a hint of possible resolution but some sugary look. Mostly non-resolved. H1_RO 02/16/10 01:20 WSprDSR 389 5mmNag 18SmF3.7Pc

<end-of-observation>

As viewed in MegaStar it should be noted that when I said 'the core does seem brighter' that was actually due to a foreground star right on top of this fairly faint glob.

I like this one too as a favorite seasonal challenge and thanks for the reminder it has 'come back around' I'll catch it maybe this Wed.

Marko

Darren Drake
February 20th, 2012, 04:07 PM
I saw it last night from my light polluted backyard in my 18. It's easy to locate the precise position because 2 bright stars point right at it. It was fairly difficult to see but definitely there. Look forward to seeing it in a dark sky. I'm wondering if Jimmy can resolve it at all in the 48....

Jeff Young
February 22nd, 2012, 10:40 AM
Copious magnification can help. I still don't have enough aperture, but at 500X I got to "grainy":


NGC2419 Intergalactic Wanderer 22/12/2006 20:51 UT; Pickering 5, NELM 5.5, SQM 20.7
16" SCT @ 500X

Fuzzball at 170X. Fuzzball at 260X (17T4, UO 18 Or. and Pentax O-18). Tried the UO 18 OPS just for fun: dim fuzzball.

Also dim at 375X and even dimmer at 500X, but starting to show hints of graniness.

Sue French
March 2nd, 2012, 08:12 PM
There are two known Milky Way globulars that are more distant than NGC 2419. You can find their distances from the Sun and from the galactic center in the latest version of Harris' CATALOG OF PARAMETERS FOR MILKY WAY GLOBULAR CLUSTERS at:
http://physwww.mcmaster.ca/~harris/mwgc.dat

Part II of the catalog gives the integrated V magnitude of NGC 2419 as 10.41, so it's not just a target for large telescopes. I have a nice sketch of it through a 105mm scope.

Recent refinements in our knowledge of the age of the universe and the age of globulars have pretty much dispelled the paradox, at least within the error bars of the determined quantities.

Best, Sue

stevecoe
March 3rd, 2012, 01:42 AM
Howdy all;

Not to make a contest out it if, but I observed this globular with only 102mm of aperture, so I beat Sue by an entire 3mm;-)
And, here is a resolution observation with a friend's 32 inch on a great night. I would love to know the magnitude of the stars I resolved with averted vision only, I don't have a magnitude chart of this cluster. Here are the observations:

2419 TV 102 Antennas 8.8mm EP faint, pretty small, brighter in the middle, averted vision makes it larger.

2419 Dave Fredericksen's 32 inch with an 8.8mm eyepiece gives 435X on a great night at Antennas Site about 100 miles from Phoenix. I rate the seeing at 7/10 and the transparency at 8/10. This distant globular is bright, pretty large, round and much brighter in the middle. There are three levels of condensation across the face of this cluster. With direct vision there are no distinct stars resolved. Averted vision shows 5 stars that come and go with the seeing. They are not easy, but I can point them out to Dave and he sees what I am seeing. So, this cluster can be resolved into stars it just takes a good 32 inch scope and a very good night.

Clear skies to us all;
Steve Coe

Sue French
March 3rd, 2012, 02:30 PM
Steve,

Guess I got to get me a 101mm :)

The tip of the red-giant branch (brightest stars) is mag 17.3
Photometry Hubble:
http://cdsarc.u-strasbg.fr/viz-bin/nph-Cat/txt?J%2FA%2BA%2F391%2F945%2Fdb/n2419.dat.gz
Photometry Saha+, 2005:
http://cdsarc.u-strasbg.fr/viz-bin/nph-Cat/html?J%2FPASP%2F117%2F37/table4.dat
Includes superimposed stars.

Sue

stevecoe
March 3rd, 2012, 06:18 PM
Sue;

I am going out tonight to look for it naked eye. :shocked:

Now that I am in the middle of this, I will attempt to post my drawing from that night. We are both new to this forum, so I do need a while to learn how to do that. I need to look up the PGC number for the nearby galaxy. I think I made it north at top and east to left.

Clear skies;
Steve Coe
111

Daniel_Sp
March 3rd, 2012, 06:33 PM
Hi guys,

a friend of mine tried with a 44"-Newton. He could NOT resolve the GC. Simple explanation: The faint stars of the GC cause a bright background from which the other stars can't get good contrast...

greetings, Daniel

Marko
March 3rd, 2012, 07:46 PM
Sue;

I am going out tonight to look for it naked eye. :shocked:

...

Clear skies;
Steve Coe
111

LOL. Good one. As a side point it is very sobering being on a chat with Steve Coe, Sue French and so many others here. Very much appreciate what I have learned from both of your individual works and postings elsewhere on web and magazine formats. What a great forum DeepSkyForum is turning out to be and thanks again to Jimi/Dragon and so on for setting it up.

stevecoe
March 4th, 2012, 01:38 AM
Daniel;

Two things...it was a very good night and I never held any of those stars with direct vision, all averted. So, I think Sue's figure of 17th mag and fainter is a pretty good estimate of the truth.

Marko, I am having fun and this is only my third post.

Clear skies;
Steve Coe

Adrian R.
March 4th, 2012, 03:53 AM
Howdy all;

Not to make a contest out it if, but I observed this globular with only 102mm of aperture, so I beat Sue by an entire 3mm;-)
And, here is a resolution observation with a friend's 32 inch on a great night. I would love to know the magnitude of the stars I resolved with averted vision only, I don't have a magnitude chart of this cluster. Here are the observations:

2419 TV 102 Antennas 8.8mm EP faint, pretty small, brighter in the middle, averted vision makes it larger.

2419 Dave Fredericksen's 32 inch with an 8.8mm eyepiece gives 435X on a great night at Antennas Site about 100 miles from Phoenix. I rate the seeing at 7/10 and the transparency at 8/10. This distant globular is bright, pretty large, round and much brighter in the middle. There are three levels of condensation across the face of this cluster. With direct vision there are no distinct stars resolved. Averted vision shows 5 stars that come and go with the seeing. They are not easy, but I can point them out to Dave and he sees what I am seeing. So, this cluster can be resolved into stars it just takes a good 32 inch scope and a very good night.

Clear skies to us all;
Steve Coe

Ha, Az. eh? Been there man. Darn near double the aperture of your scope compared to us chumps here in the Midwest who think a good night is seeing 5th magnitude stars LOL!

Deepsky-NM
March 10th, 2012, 05:02 AM
I've also heard this wonderful albeit quite distant glob referred to as the "Intergalactic Tramp".

rmollise
April 13th, 2012, 01:54 AM
Give it another try under better conditions. I assume your conditions were not excellent, since when you are out in the dark, it is pretty good in my 8-inch SCT, Celeste.

timokarhula
August 9th, 2012, 12:40 PM
Howdy all;

Not to make a contest out it if, but I observed this globular with only 102mm of aperture, so I beat Sue by an entire 3mm;-)

2419 TV 102 Antennas 8.8mm EP faint, pretty small, brighter in the middle, averted vision makes it larger.

Clear skies to us all;
Steve Coe

Howdy all! My first post here. I have not been reading posts in this forum very long.

Steve, I have beaten you by 2 mm :-) In April 2007, I viewed NGC2419 with my 25x100 binoculars. It was actually a tad easier than NGC5053 in Coma Berenices which I saw half an hour earlier and which I have glimpsed even with 18x50 Canon IS binoculars. In fact, almost all NGC-globulars can be seen with binoculars from dark sites.

/Timo Karhula

Dragan
September 24th, 2012, 10:01 PM
Here's an interesting paper. Turns out, our beloved 2419 may not be a globular after all! :shocked:

http://arxiv.org/abs/1209.2705

Marko
September 25th, 2012, 03:58 AM
It seems odd they would say it is not a globular but is the core of a dwarf galaxy. This seems strange because one of the now becoming more popular ideas is that quite a few globs are left over cores of galaxies that have been devoured by the larger mass of stars of the galaxy they surround. So I'm sticking by the label of globular for the lil tramp just as Pluto is most certainly STILL a planet. :P