Resembling a gigantic hubcap in space, a 3,700-light-year-wide dust disk encircles a 300-million- solar-mass black hole in the center of the elliptical galaxy NGC 7052.

The disk, possibly a remnant of an ancient galaxy collision, will be swallowed up by the black hole in several billion years. The black-and-white image on the left, taken by a ground-based telescope, shows the complete galaxy. The Hubble picture on the right is a close-up view of the dust disk surrounding the black hole.

Astronomers have seen the exhaust products of black hole "engines": narrow beams of material traveling at nearly the speed of light. But they could only speculate where and how those beams were created. Now astronomers have gained their first glimpse at the mysterious region near a black hole at the heart of a distant galaxy where those columns of material are formed. Images of this phenomenon, taken by radio telescopes in Europe and the U.S., are the most detailed ever of the center of the galaxy M87, some 50 million light-years from Earth.

Astronomers using the Hubble telescope and ground-based observatories have discovered the first examples of isolated, stellar-mass  adrift among the stars in our Milky Way Galaxy. They detected two of these lonely, invisible objects indirectly by measuring how their extreme gravity bends the light of a more distant star behind them. All previously known "stellar"  have been found orbiting normal stars. Astronomers determined the presence of those compact powerhouses by examining their effect on their companion star. These new results suggest that black holes are common and that many massive but normal stars may end their lives as black holes instead of neutron stars, the crushed cores of massive stars that end their lives in supernova explosions. The findings also suggest that stellar-mass  do not require some sort of interaction in a double-star system to form but may be produced in the collapse of isolated, massive stars, as has long been proposed by stellar theorists.

Streaming out from the center of the galaxy M87 like a cosmic searchlight is one of nature's most amazing phenomena, a black-hole-powered jet of electrons and other sub-atomic particles traveling at nearly the speed of light. In this Hubble telescope image, the blue jet contrasts with the yellow glow from the combined light of billions of unseen stars and the yellow, point-like clusters of stars that make up this galaxy. Lying at the center of M87, the monstrous black hole has swallowed up matter equal to 2 billion times our Sun's mass. M87 is 50 million light-years from Earth.

A monstrous black hole's rude table manners include blowing huge bubbles of hot gas into space. At least, that's the gustatory practice followed by the supermassive black hole residing in the hub of the nearby galaxy NGC 4438. These NASA Hubble Space Telescope images of the galaxy's central region clearly show one of the bubbles rising from a dark band of dust. The other bubble, emanating from below the dust band, is barely visible, appearing as dim red blobs in the close-up picture of the galaxy's hub (the colorful picture at right). The background image represents a wider view of the galaxy, with the central region defined by the white box.

Astronomers are concluding that monstrous  weren't simply born big but instead grew on a measured diet of gas and stars controlled by their host galaxies in the early formative years of the universe. These results, gleaned from a NASA Hubble Space Telescope census of more than 30 galaxies, are painting a broad picture of a galaxy's evolution and its long and intimate relationship with its central giant black hole. Though much more analysis remains, an initial look at Hubble evidence favors the idea that titanic  did not precede a galaxy's birth but instead co-evolved with the galaxy by trapping a surprisingly exact percentage of the mass of the central hub of stars and gas in a galaxy. 

The Hubble telescope has taken a snapshot of a nearby active galaxy known as Circinus. This active galaxy belongs to a class of mostly spiral galaxies called Seyferts, which have compact centers and are believed to contain massive . Seyfert galaxies are themselves part of a larger class of objects called Active Galactic Nuclei or AGN. AGN have the ability to remove gas from the centers of their galaxies by blowing it out into space at phenomenal speeds. Astronomers studying the Circinus galaxy are seeing evidence of a powerful AGN at its center. 

The Hubble telescope may have, for the first time, provided direct evidence for the existence of black holes by observing how matter disappears when it falls beyond the "event horizon," the boundary between a black hole and the outside universe. Astronomers found their evidence by watching the fading and disappearance of pulses of ultraviolet light from clumps of hot gas swirling around a massive, compact object called Cygnus XR-1. This activity suggests that the hot gas fell into a black hole. 

Data from the Space Telescope Science Institute's Digitized Sky Survey has played an important supporting role in helping radio and X-ray astronomers discover an ancient black hole speeding through the Sun's galactic neighborhood. The rogue black hole is devouring a small companion star as the pair travels in an eccentric orbit looping to the outer reaches of our Milky Way galaxy. It is believed that the black hole is the remnant of a massive star that lived out its brief life billions of years ago and later was gravitationally kicked from its home star cluster to wander the Galaxy with its companion.

Medium-size  actually do exist, according to the latest findings from NASA's Hubble Space Telescope, but scientists had to look in some unexpected places to find them. The previously undiscovered black holes provide an important link that sheds light on the way in which  grow. Even more odd, these new black holes were found in the cores of glittering, "beehive" swarms of stars called globular star clusters, which orbit our Milky Way and other galaxies. The black hole in globular cluster M15 [left] is 4,000 times more massive than our Sun. G1 [right], a much larger globular cluster, harbors a heftier black hole, about 20,000 times more massive than our Sun.