Latest Black holes Stories

2011-01-19 09:27:52

One of the most important predictions of Einstein's theory of General Relativity is the existence of black holes. The dynamics of these systems are not yet fully understood, but researchers from Queen Mary, University of London have now provided a rigorous way of determining the evolutionary stage of a black hole by analysing the region outside where matter cannot escape, the event horizon. Dr Thomas Bäckdahl and Dr Juan A. Valiente Kroon at Queen Mary's School of Mathematical Sciences...

2011-01-18 12:30:00

A team of UBC physicists and engineers have designed an experiment featuring a trough of flowing water to help bolster a 35-year-old theory proposed by eminent physicist Stephen Hawking. In 1974, Hawking predicted that black holes--often thought of having gravitational pulls so strong that nothing escapes from them--emit a very weak level of radiation. According to the theory, pairs of photons are torn apart by a black hole's gravitational field--one photon falls into the black hole, but the...

2010-12-27 09:25:00

TAU astronomers identify the epoch of the first fast growth of black holes Most galaxies in the universe, including our own Milky Way, harbor super-massive black holes varying in mass from about one million to about 10 billion times the size of our sun. To find them, astronomers look for the enormous amount of radiation emitted by gas which falls into such objects during the times that the black holes are "active," i.e., accreting matter. This gas "infall" into massive black holes is believed...

2010-12-20 14:57:21

A new study from NASA's Chandra X-ray Observatory tells scientists how often the biggest black holes have been active over the last few billion years. The object could help scientists better understand how massive stars explode, which ones leave behind black holes or neutron stars, and how many black holes are in our galaxy and others. This discovery clarifies how supermassive black holes grow and could have implications for how the giant black hole at the center of the Milky Way will behave...

2010-11-19 09:04:40

"ËœDavid and Goliath' scenario explores extreme mass ratios (Goliath wins) Scientists have simulated, for the first time, the merger of two black holes of vastly different sizes, with one mass 100 times larger than the other. This extreme mass ratio of 100:1 breaks a barrier in the fields of numerical relativity and gravitational wave astronomy. Until now, the problem of simulating the merger of binary black holes with extreme size differences had remained an unexplored region of...

2010-11-08 19:23:18

Lasers produce the first Hawking radiation ever detected A team of Italian scientists has fired a laser beam into a hunk of glass to create what they believe is an optical analogue of the Hawking radiation that many physicists expect is emitted by black holes. Although the laser experiment superficially bears little resemblance to ultra-dense black holes, the mathematical theories used to describe both are similar enough that confirmation of laser-induced Hawking radiation would bolster...

2010-09-08 09:34:32

Team led by University of Leicester confirm presence of ultra-bright object in nearby galaxy A group of international astronomers in the UK, France and the USA, led by the University of Leicester, have found proof to confirm the distance and brightness of the most extreme ultra-luminous X-ray source, which may herald a new type of Black Hole. The X-ray source, HLX-1, is the most extreme member of an extraordinary class of objects "“ the ultra-luminous X-ray sources "“ and is...

2010-07-22 06:39:06

Scientists have found evidence that a giant black hole has been jerked around twice, causing its spin axis to point in a different direction from before. This discovery, made with new data from NASA's Chandra X- ray Observatory, might explain several mysterious-looking objects found throughout the Universe. The axis of the spinning black hole is thought to have moved, but not the black hole itself, so this result differs from recently published work on recoiling black holes. "We think this is...

2010-07-19 07:10:00

Astronomers use infrared "eyes" to shed light on black holes. A new infrared image has captured the center of our galaxy in never-before-seen detail--showing stars and gas swirling into the super massive black hole that lurks at the heart of our own Milky Way. "We can't actually see a black hole because, by definition, no light comes out from it," says University of Florida astronomer Steve Eikenberry. "What we can see, though, is the material around the black hole. As the material spirals...

2010-07-01 06:20:00

Evidence for a recoiling black hole has been found using data from the Chandra X-ray Observatory, XMM-Newton, the Hubble Space Telescope (HST), and several ground-based telescopes. This black hole kickback was caused either by a slingshot effect produced in a triple black hole system, or from the effects of gravitational waves produced after two supermassive black holes merged a few million years earlier. The discovery of this object, located in this composite image, comes from a large,...

Latest Black holes Reference Libraries

2004-10-19 04:45:42

Supermassive Black Hole -- A Supermassive black hole is a black hole with a mass in the range of millions or billions solar masses. A supermassive black hole has some interesting properties differing from his low-mass cousins: -- The average density of a supermassive black hole can be very low, and actually can be lower than water's density. This happens because the black hole diameter increases linearly with mass, and consequently density drops much faster. -- Strong tidal...

2004-10-19 04:45:42

Seyfert Galaxy -- Seyfert galaxies are spiral or irregular galaxies containing an extremely bright nucleus, most likely caused by a supermassive black hole, that can sometimes outshine the surrounding galaxy. The light from the central nucleus varies in less than a year, which implies that the emitting region must be less than one light year across. They are named for the astronomer Carl Seyfert, who studied them extensively in the 1940s. They are a subclass of active galactic nuclei....

2004-10-19 04:45:41

Microquasar -- Microquasars are smaller cousins of quasars. They are named after quasars, as they have some common characteristics: strong and variable radio emission often seen as radio jets, and an accretion disk surrounding a black hole. In quasars, the black hole is supermassive (millions of solar masses) as in microquasars, the black hole mass is a few solar masses. In microquasars, the accreted mass comes from a normal star and the accretion disk is very luminous in optical regions...

2004-10-19 04:45:41

Event Horizon -- The event horizon is a boundary beyond which information will never reach an observer. An event horizon is a mathematical construct and not a physical object and a person passing through an event horizon will not notice any odd behavior. From an outside observer however, an object passing though an event horizon will appear redder and dimmer and will appear to freeze at the moment the object passes the event horizon. An event horizon can form around a gravitational...

2004-10-19 04:45:41

Black Hole -- Black holes are objects so dense that not even light can escape their gravity. They are believed to form from the gravitational collapse of astronomical objects containing two or more solar masses. Astronomical observations suggest that the center of most galaxies, including our own Milky Way, contain supermassive black holes containing millions to billions of solar masses. Black holes are predictions of Einstein's theory of general relativity. In particular, they occur...

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Word of the Day
  • A small crescent-shaped structure or marking, especially the white area at the base of a fingernail that resembles a half-moon.
This word is a diminutive of the Latin 'luna,' moon.