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Using four years of data from the Hubble Space Telescope’s Advanced Camera for Surveys, astronomers have made the most accurate measurements of the movement of stars in the globular cluster Omega Centauri, and now can predict their movements for the next 10,000 years. This “beehive” of stars is tightly crammed together, so resolving the individual stars was a job that perhaps only Hubble could do. “It takes high-speed, sophisticated computer programs to measure the tiny shifts in the positions of the stars that occur in only four years’ time,” says astronomer Jay Anderson of the Space Telescope Science Institute in Baltimore, Md., who conducted the study with fellow Institute astronomer Roeland van der Marel. “Ultimately, though, it is Hubble’s razor-sharp vision that is the key to our ability to measure stellar motions in this cluster.”
Astronomers say that the precise measurement of star motions in giant clusters can yield insights into how stellar groupings formed in the early universe, and whether an “intermediate mass” black hole, one roughly 10,000 times as massive as our Sun, might be lurking among the stars.
Analyzing archived images taken over a four-year period by Hubble’s astronomers have made the most accurate measurements yet of the motions of more than 100,000 cluster inhabitants, the largest survey to date to study the movement of stars in any cluster.
The astronomers used the Hubble images, which were taken in 2002 and 2006, to make a movie simulation of the frenzied motion of the cluster’s stars. The movie shows the stars’ projected migration over the next 10,000 years.
Omega Centauri is the biggest and brightest globular cluster in the Milky Way, and one of the few that can be seen by the unaided eye. It is located in the constellation Centaurus, Omega Centauri, so is viewable in the southern skies, and is one of about 150 such clusters in our Milky Way Galaxy.
In this video below, astronomers Jay Anderson and Roeland van der Marel discuss their in-depth study of the giant cluster Omega Centauri.
Source: HubbleSite
THEY’RE COMING RIGHT FOR US!
(just kidding :^D)
I had a fight with some weird guy on Youtube claiming that Earth had these up and down cycles when it goes above and below the milky way disk and that proof is in he bible and historical facts.
I claimed that the sun does not move up and down with a elliptical period just like Earth does but gets influenced by all stars it passes and might not have an ellipse at all.
I could not have a chance to tell him that in 6000 years Earth barely moved in the big scheme of our galaxy. So there would not be any historical facts proving his claim.
The question is now, have we evidence of an elliptical orbit? Or have we evidence that the orbit is pretty irregular because of some gravity assist by a passing star?
Note: I couldn’t tell him the second part since he blocked me claiming that I don’t understand gravity. LOL
On a more serious note, do the motions that have been predicted take into account the effects of gravity that these stars have on one another? They all look like they are going in a straight line in the video, so that part’s a little unclear.
Olaf: Never fight a land war in Asia, and never, ever get into a scientific “argument” on YouTube. :^P
I agree Dave Finton , but couldn’t resist
I got this reply: and he blocked me, so I cannot react:
>> “you? are 100% wrong and illiterate about the true motions of our Cosmos!”
He already sent me another message, but can’t respond since he blocked me. LOL
But I am really curious if the sun could be in slingshot out of the milky way when it passes a group of stars very close by. I did many simulations back then with gravity and once in a while when you have a 1000 stars some star did get ejected outside the cluster at amazing speeds. I am not sure if this would be possible to be ejected outside the milky way, you probably have to zip passed a few hundreds of stars closely in order to have the required gravity assist.
From: http://www.spacetelescope.org/news/heic0809/
“Omega Centauri has several characteristics that distinguish it from other globular clusters: it rotates faster than a run-of-the-mill globular cluster, its shape is highly flattened and it consists of several generations of stars — more typical globulars usually consist of just one generation of old stars.”
One might assume that the ‘Beehive’ like nature or activity in the stars of the above is due to “several generations of stars” in their respective orbits around a central mass. If this is true then groups of objects orbiting similarly probably have a shared or common origin? This might indicate that Omega Centauri grew to as large as it is due to the continued cannibalization of other, smaller globular clusters?
“Moreover, Omega Centauri is about 10 times as massive as other big globular clusters, almost as massive as a small galaxy. These peculiarities have led astronomers to suggest that Omega Centauri may not be a globular cluster at all, but a dwarf galaxy stripped of its outer stars by an earlier encounter with the Milky Way. “Finding a black hole at the heart of Omega Centauri could have profound implications for our understanding of its past interaction with the Milky Way”, said Noyola.”
This statement seems to indicate that Omega Centauri may have lost substantial mass to the Milky Way at one time… and may also have captured halo or high orbit stellar wanderers during its passage, thereby adding to the orbital menagerie?
i wonder how the night sky on a hypotetical planet in Omega Centauri would look like. i suppose the most thrilling sight would be from the fringe – one hemisphere black, but the other gleaming with thousands of star, some of them maybe as bright as our moon.
Globular clusters are gravitationally bound, so the motion of their stars is governed by gravity. The motions iterated into the future here though is based on redshifts and iterated into a short time into the future. These motions are tangent vectors to the actual motions. However, for short time periods into the future these diverge little from the actual motion.
LC
I’ve seen Omega Centauri several times from my 38.5 N Lat. location Its ALWAYS an exciting object to see!
We are 75 miles North and 20 miles West of the greater San Francisco Bay area. Some nights the whole Bay Area including nearby Santa Rosa gets fogged in, darkening completely the already fairly dark Southern and SE skies. There are no interfering light sources in the Northern and Western skies. On moonless nights I am a regular visitor to viewing sites the nearby coastal mountains. With only one or two mountain ridges between me and the sea, late night laminar air flow off the ocean settles the atmosphere into excellent seeing conditions – this at 1,500 feet..
Anyone living nearby who wants to go ‘do’ some ‘road side’ astronomy is welcome to try my skies!
Hmmm… “Drive By Astronomy”… sounds MUCH better than, “Road Kill Astronomy”… eh?
Whassat on the Barbie? (LOL!)