Posted on 06/30/2018 4:56:13 PM PDT by Simon Green
(much larger hi-res picture at link)
Globular clusters are gravitationally-bound groupings of stars which orbit galaxies.
These objects typically contain hundreds of thousands of stars that are thought to have formed at roughly the same time as their host galaxy.
They are denser and more spherical than open star clusters like the famous Pleiades.
The large mass in the rich stellar center of the cluster pulls the stars inward to form a ball of stars. The word globulus, from which these clusters take their name, is Latin for small sphere.
It is thought that every galaxy has a population of globular clusters. Some galaxies have a few hundred, while giant ellipticals can have several thousand.
Our Milky Way Galaxy is orbited by at least 150 globular clusters, including NGC 6139.
First discovered in May 1826 by Scottish astronomer James Dunlop, NGC 6139 is some 35,000 light-years distant.
The cluster is seen roughly in the direction of the center of the Milky Way, in the constellation of Scorpius.
Most globular clusters are estimated to be over 10 billion years old.
As a result they contain some of the oldest stars in the Milky Way, formed very early in its history. However, their role in galactic evolution is still a matter of study.
This image of NGC 6139 is a composite of separate exposures acquired by Hubble’s Wide-Field Camera 3 (WFC3) instrument.
Two filters — a blue (F438W) filter and a wide-band (F555W) filter – were used to sample various wavelengths.
The color results from assigning different hues to each monochromatic image associated with an individual filter.
(Excerpt) Read more at sci-news.com ...
Btw, thanks.
Wow, that is one solid base! Impressive.
I had to make the floor isolated/not touching the pier, so that when I walk around the scope it doesn’t cause vibration during imaging. It would otherwise. Btw, everything the camera/scope sees, is seen on one of two LED monitors where software controls the guidance, scope, and camera.
Ah, just as I thought.
Agree. ‘Boggles the mind’ is a most appropriate term. I never get bored thinking about the distances and the size of some of these objects. Earth in comparison is a like an atom or molecule out here spinning like a top in a giant rotating pinwheel of stars. I find it all fascinating.
M-1 or the Crab Nebula - At about 6300 light years from Earth. M-1 is the remnant of a star that exploded as a supernova which was bright enough to be observed by the ancient Chinese in 1054
M1/NGC 1952 14x60s
Thanks colorado tanker, nice topic to ping the former APoD list.
If the radiation level would allow life to ever get started.
I am so inferior, cannot even get a poor shot of M31.
Because it is so big, M31 is really hard to shoot through a scope.
If you have a dslr and a tripod, try just pointing it in the area of m31 and take a few 10 or 15 sec exposiers. You may be surprised.
I did try that, aimed where I thought it should be, got a small, faint orange blob. More exposure just got ruined by light pollution. Need a totally haze free night I suppose.
Globular cluster?.......................
“and here they are, Dolly Parton”.
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