black holes

VLT and Rossi XTE satellite probe violently variable black holes

harminka — Wed, 15 Oct 2008 12:06:42 -0500

Unique observations of the flickering light from the surroundings of two black holes provide new insights into the colossal energy that flows at their hearts. By mapping out how well the variations in visible light match those in X-rays on very short timescales, astronomers have shown that magnetic fields must play a crucial role in the way black holes swallow matter.

Yale astronomer discovers upper mass limit for black holes

harminka — Fri, 12 Sep 2008 07:18:34 -0500

There appears to be an upper limit to how big the universe’s most massive black holes can get, according to new research led by a Yale University astrophysicist.

Polarized sunglasses see black hole disks

harminka — Fri, 25 Jul 2008 01:27:56 -0500

For the first time astronomers have found a way to get a clean view of the elusive disks of matter surrounding supermassive black holes. By using a polarising filter on the Science and Technology Facility Council’s UK Infrared Telescope (UKIRT) in Hawaii, they have been able to see through the clouds of dust which surround these black holes. This work is published on 24th July 2008 in Nature.

Accretion discs show their true colors

harminka — Fri, 25 Jul 2008 01:11:57 -0500

Quasars are the brilliant cores of remote galaxies, at the hearts of which lie supermassive black holes that can generate enough power to outshine the Sun a trillion times. These mighty power sources are fuelled by interstellar gas, thought to be sucked into the hole from a surrounding 'accretion disc'.

Object intermediate between normal supernovae and gamma-ray bursts

harminka — Thu, 24 Jul 2008 14:30:04 -0500

A European-led team of astronomers are providing hints that a recent supernova may not be as normal as initially thought. Instead, the star that exploded is now understood to have collapsed into a black hole, producing a weak jet, typical of much more violent events, the so-called gamma-ray bursts.

Polarizing filter allows astronomers to see disks surrounding black holes

harminka — Thu, 24 Jul 2008 08:40:07 -0500

For the first time, a team of international researchers has found a way to view the accretion disks surrounding black holes and verify that their true electromagnetic spectra match what astronomers have long predicted they would be. Their work will be published in the July 24 issue of the science journal Nature.

New method to weigh giant black holes

harminka — Thu, 17 Jul 2008 09:20:45 -0500

How do you weigh the biggest black holes in the universe? One answer now comes from a new and independent technique that UC Irvine scientists and other astronomers have developed using data from NASA’s Chandra X-ray Observatory.

Safety of large hadron collider

harminka — Mon, 30 Jun 2008 05:10:19 -0500

Particle colliders creating black holes that could devour the Earth. Sounds like a great Hollywood script.

Radio telescopes reveal unseen galactic cannibalism

harminka — Tue, 24 Jun 2008 07:33:44 -0500

Radio-telescope images have revealed previously-unseen galactic cannibalism -- a triggering event that leads to feeding frenzies by gigantic black holes at the cores of galaxies. Astronomers have long suspected that the extra-bright cores of spiral galaxies called Seyfert galaxies are powered by supermassive black holes consuming material. However, they could not see how the material is started on its journey toward the black hole.

Black holes have simple feeding habits

harminka — Thu, 19 Jun 2008 14:31:00 -0500

The biggest black holes may feed just like the smallest ones, according to data from NASA's Chandra X-ray Observatory and ground-based telescopes.

Searching the heavens

harminka — Fri, 02 May 2008 06:18:42 -0500

A new space mission, due to launch this month, is going to shed light on some of the most extreme astrophysical processes in nature - including pulsars, remnants of supernovae, and supermassive black holes.

Radio telescope reveals secrets of massive black hole

harminka — Wed, 23 Apr 2008 12:31:55 -0500

At the cores of many galaxies, supermassive black holes expel powerful jets of particles at nearly the speed of light. Just how they perform this feat has long been one of the mysteries of astrophysics.