Terzan Trio

[John Hothersall]

SPX350 F4.53, ATK-16HR, Astrodon filters.

Terzan 1,4 and 5.

Having a go at some Terzans which seem littered all over the galactic core pretty close to one another, they don't image well in Moonlight but don't take long to image. Terzan 5 is only 2 light years away from the centre of the Milkyway.

RGB
R=8x5m
GB=5x5min.

Thanks, John.

[multiweb (Marc)]

Very nicely resolved. Quite a collection now.

[desler]

That really is a very impressive collection John. Nicely done!

Darren

[Stevec35 (Steve)]

Very well done John. I must admit I'm surprised that so much is visible in straight RGB given that these clusters were (I think) discovered on infrared plates. The detail you have recorded is superb.

Cheers

Steve

[Alchemy (Clive)]

Resolution is superb, nicely done.

You certainly have a great working setup there, I have no idea how you got the 15inch scope on an EQ6 ..... But you got it humming!

[John Hothersall]

Yes these do pick up well in the red filter and green shows quite a blemish of stars. This is Terzan 2 was taken with near full Moon so is quite a lot noisier than the others. The EQ6 does well at its payload limit but after it crosses the meridian guidestar can jump for some reason until I do a flip.

John.

[Ross G]

An impressive capture John.

Something new to me.

Thank you.

Ross.

[SkyViking (Rolf)]

Excellent images John, they look very 3D and one can really see how the clusters are far behind the foreground stars and reddened by the dust. Terzan 5 is almost comet shaped, something I also noticed when imaging it. It's apparently not a true globular but rather a remnant core of a dwarf galaxy. I think it's located 0.6kpc from the galactic centre.

[gregbradley]

Great captures John. Its interesting to image something so close to the centre of our galaxy.

Greg.

[Martin Pugh]

Hey John
I was unaware of these, and you have resolved them well - great job.

Martin

[Hagar (Doug)]

Nice collection of unusual targets John, At least you lways seem to keep us guessing what will be next.

[madbadgalaxyman (Robert)]

Some very interesting star clusters in your images, John.

The most massive and compact Milky Way star cluster that springs to mind is the NGC 3603 cluster (I think that the cluster and the surrounding neb probably have the same NGC number)



This cluster is neither exactly an open star cluster nor a globular cluster.......it is so massive that it has adopted the structure and symmetry of a globular star cluster, so it is best thought of as a newly formed low mass globular star cluster (that is, with young stars).
Nonetheless, a tough object because of its small angular size.


Another of these clusters straddling the Open-cluster/Globular Cluster boundary is Westerlund 1 . However, I am not sure if recent research still supports this conclusion.

Taking an overview of the cluster population in our own Galaxy and elsewhere in the nearest galaxy groups, it would seem that the most parsimonious interpretation of the highest mass young clusters known in the nearby galaxies is that these are newly formed young globular clusters.

cheers,
bad galaxy man

[atalas]

Hi John

Great work! just reading up on Terzan 5,how It has two generation of stars of about 6 to 12 billion years old,wow!

It also seems that they believe it could be the remaining core of a galaxy...interesting.

So,the remaining core of a galaxy near the center of the milky way? must of been a dwarf before It got devoured....fascinating stuff.

[strongmanmike (Michael)]

These are super John, you have done a great processing job too, they look so distant .

If I ever get an observatory again (sorry) I think I will need to have the longer focal length option available, so many cool small things to target.

Mike

[John Hothersall]

Thanks again for comments and thankyou Robert for the info on N3603, so much to learn in the Southern Hemisphere. Terzan 5 was interesting to read about before I imaged it with the 2 generations of stars and speculative history.

John.

[Dennis]

Lovely work John – it’s fascinating to see these off the beaten track objects and so well presented too!

Cheers

Dennis

[madbadgalaxyman (Robert)]

Since I last looked into the nature of Westerlund 1, it seems that a whole industry has sprung up to study it.....a search of //adsabs.harvard.edu for recent papers about this object finds plenty of them.
(I have been off studying external galaxies for years....and I have been neglecting the Milky Way e.g. the last three days was devoted to thinking about a particular Abell cluster)

In the optical regime, Westerlund 1 is actually deeply unimpressive , as can be seen in the ESO press release eso1034 , but it turns out that it is the most massive young star cluster that we know of in our own Galaxy.
Its total mass of ~100,000 solar masses is well within the range of masses that we find for the (old) globular clusters in our own Galaxy.

Optical image (with the ESO/MPG 2.2m telescope) :



Maybe a CCD with an extended red response might capture it a bit better!

Unfortunately for us, there are 11 (!!) magnitudes of visual extinction in front of this magnificent object.
Because of this, young globular-like star clusters were first discovered in other galaxies, and only much later in our own Galaxy!
( I seem to recall a study of M83 indicating that it probably has plenty of young star clusters that are of a similar mass to an "old" globular star cluster.)