Black Holes pictures from the Hubble Space Telescope.

http://space.about.com/od/blackholes/ig/Black-Holes-Pictures-/Formed when a massive star collapses from its own gravity, black holes have such a strong pull of gravity that not even light can escape from them.

Today's scientists believe that a black hole is the end product in the lifecycle of a giant star. If this star is three or four times as massive as our own sun, even after it has exhausted all its fuel, then it can collapse under its own gravity. Just like a crab burying itself at the beach and pulling the sand down over itself, the collapsing star pulls in everything around it as well.

These Black Holes pictures are from the Hubble Space Telescope.

Milky Way's Super-massive Black Hole

New Virtual Telescope Zooms In On Milky Way's Super-massive Black Hole

ScienceDaily (Sep. 5, 2008) — An international team, led by astronomers at the MIT Haystack Observatory, has obtained the closest views ever of what is believed to be a super-massive black hole at the center of the Milky Way galaxy.

The astronomers linked together radio dishes in Hawaii, Arizona and California to create a virtual telescope more than 2,800 miles across that is capable of seeing details more than 1,000 times finer than the Hubble Space Telescope. The cosmic target of the observations was the source known as Sagittarius A* ("A-star"), long thought to mark the position of a black hole whose mass is 4 million times that of the sun. Though Sagittarius A* was discovered three decades ago, the new observations for the first time have an angular resolution, or ability to observe small details, that is matched to the size of the black hole "event horizon" — the region inside of which nothing, including light, can ever escape.  Continue to read

Mystery Of Young Stars Near Black Holes

Until now, scientists have puzzled over how stars could form around a black hole, since molecular clouds - the normal birth places of stars - would be ripped apart by the black hole's immense gravitational pull.

However, the new study by Professor Ian Bonnell (St Andrews) and Dr Ken Rice (Edinburgh) found that stars appear to form from an elliptical-shaped disc, the remnant of a giant gas cloud torn apart as it encounters a black hole.

The discovery of hundreds of young stars, of high masses and making oval-shaped orbits around a black hole three million times more massive than the sun, and at the centre of our Galaxy, is described as one of the most exciting recent discoveries in astrophysics.

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Black holes and the formation of stars

Now Ian Bonnell, an astronomer at the University of St Andrews in Scotland, and William Ken Rice of the University of Edinburgh have created a computer simulation that offers a possible explanation for how the stars could have formed. They detailed their model in the Aug. 22 issue of the journal Science.

In their model, a giant gas cloud plunges in toward the black hole. As it gets close, much of the cloud is ripped apart by the black hole's gravity, though some portion of it survives because of the turbulence of the gas in the cloud.

This remnant forms an oval disk of gas orbiting around the black hole, gravitationally bound but beyond the range within which it would be sucked in. Variations in the density of the material in the disk then cause it to condense into stars and break up, leaving the stars in an oval orbit around the black hole where the disk used to be.

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