A Globular Feast

[Mike JW]

Hi Callum, thanks for your post. Pal 13 is certainly tricky to locate/observe. Mike

[Mike JW]

A visit to NGC 2419 (The Intergalactic Wanderer) was well worth it.  

 

Mike

Edited January 13, 2021 by Mike JW

[Mike JW]

M3 in CVn made for a nice diversion from chasing galaxies on 30/3/21. Its age is thought to be about 11.8 billion years and is classified in group 6 (mild concentration of stars towards the centre), contains around 500,000 stars, and lies about 33,900 lyrs from us, it is 180 to 200 lyrs across.. Its central core is just 11 light years across. The brightest stars are about mag 12.7. As it orbits the Milky Way, it can be as far out as 66,000 lyrs from the galaxy centre and get as close as 22,000 lyrs at which point some of the outer stars maybe stripped away. 268 variable stars have been located in this cluster.

[Bill S]

Well it was a bit of a bright moon the other night and I had decided to do a bit more LRGB observing using Jocular. No sign of any brightish planetary nebulae but a couple of globulars looked worth a glance.

Messier 3 has been well described by MikeJW in the post before this one. Here's what a bit of colour gave.

 

I then had a look at the nearby M53.  This one is a bit further away than M3 at around 60,000 light years in Coma Berenices. M3 is Shapley-Sawyer class VI (intermediate mild concentration) whereas this one is said to be a slightly tighter class V (intermediate concentrations).

 

So after these too I had a look at NGC 5466. This is in Bootes and is about 52,000 ly away. It's a much looser class XII (almost no concentration towards the centre).

It has been found to be the source of an extensive tidal tail stretching more than 40 degrees. This has been pulled out by its passage closer to the centre of the galaxy (perigalacticon - I did not know there was such a word!) and has been extensively studied.

e.g. https://arxiv.org/pdf/1204.5771.pdf

 

Globular clusters - always worth a look!

Bill S

 

 

 

[Mike JW]

Hi Bill, colour certainly adds interest.

Mike

[Mike JW]

Pal 5 in Serpens. I visited this globular as recorded at the start of this thread. Here it is again but this time with the 15/ultrastar set up. Even with this large aperture and over 5 minutes of exposure it is still very faint.

Mike

[Martin Meredith]

Here are a few globs from last night. They are all from quite low altitudes so highly reddened. Scale is same apart from the last shot.

 

And finally, our old favourite sparse cluster, Pal 5, of which there are lots of images further up the thread

 

This shot has the 1.8 billion light year galaxy cluster Abell 2050 in the top left corner (some galaxies can be made out). Distance estimate to Pal 5 is around 75k light years, so the galaxies are about 25000 times as far away as the globular cluster.

Martin

 

 

[JeremyS]

Super collection of globs @Martin Meredith 👍🏻

[Martin Meredith]

Thanks Jeremy. its always fun to look at several in the same session. If nothing else its a reminder that not all globs are the same!

Martin 

[Mike JW]

Hi Martin, You did well with the Pal 5 - so much better than my set up.  Makes me think I should try again but you do have the advantage of it being higher in the sky. Envious of you being able to get the low down globs.

Mike

[Mike JW]

Time we had another globular in this thread.

Pal 2 in Auriga. It is one of the more distant globulars at around the 90,000 lyrs from us. It has a very eccentric orbit and currently is thought to be at its closest to the galactic centre. It is also heading towards at around 133km/s - a bit of a long wait before we get a close up view. The cluster is also partially obscured by lying in the the galactic plane. As it is an old cluster it will have plenty of red stars.

Mike