Movie reveals details of massive star formation Nov 20, 2009
Capturing the birth of massive stars is challenging, since not only are they rare, but they tend to spend their early years enveloped in dust and gas, preventing them from being seen in visible light, but the new movie reveals that massive stars form much like their smaller siblings, with a rotating accretion disc and magnetic fields playing crucial roles ... The current data does not show whether the magnetic field arises in the star or in the accretion disc, but future observations planned... (Astronomy Now Online)
Are Earth's Oceans Made Of Extraterrestrial Material? Nov 12, 2009
The Earth's water could therefore be extraterrestrial, have arrived late in its accretion history, and its presence could have facilitated plate tectonics even before life appeared ... The arrival of water on Earth therefore corresponds to a late episode of planetary accretion ... Volatile accretion history of the terrestrial planets and dynamic implications. (Science Daily)
Middleweight Black Hole: Swift, XMM-Newton Satellites Tune Into X-ray Source Nov 11, 2009
XMM-Newton detected what the astronomers call "quasi-periodic oscillations," a nearly regular "flickering" caused by the pile-up of hot gas deep within the accretion disk that forms around a massive object. The rate of this flickering was about 100 times slower than that seen from stellar-mass black holes. (Science Daily)
Rapid Supernova: New Class Of Exploding Star? Nov 6, 2009
Artist's impression of an AM-CVn star system, where helium flows from one star, a helium white dwarf (upper right), onto another, piling up in an accretion disk around a small, dense primary star. Helium from the disk eventually falls onto the star, forming a shell that may end up exploding as a Type. (Science Daily)
Bizarre Galaxy Result Of Cosmic Collision Oct 14, 2009
Matter is pulled toward the black hole, forming an accretion disc. The energy released by the frenzied motion heats up the disc, causing it to emit across a wide swath of the electromagnetic spectrum. (Science Daily)
Dirty Stars Make Good Solar System Hosts Oct 7, 2009
But if the fraction of pebbles is increased slightly, the clumping increases dramatically and quickly results in the accretion of sufficient material to make larger-scale planetesimals. These mini-planets work as planetary building blocks, merging over millions of years to form planets. (Science Daily)
Our changing view of the moon Oct 6, 2009
Before the collision theory began to hold sway, other explanations for the moon's formation included fission of the Earth by centrifugal forces (the severed chunk leaving behind a large basin, usually named as the Pacific Ocean); capture of the moon after it formed elsewhere and wandered into the Earth's neighborhood; and formation at the same time as the Earth from the primordial accretion disk around the sun. With the end of the Apollo program, interest in the moon tapered off until more... (MSNBC -- Technology)
New photos reveal Milky Ways chaotic center Sep 23, 2009
The region is clouded with diffuse X-ray light from young stars, dying stars, and even emerged poured out by the accretion disk of material falling onto Sagittarius A. NASA / CXC / UMass / D. Wang et al.A new color-coded image of the Milky Way's center highlights X-ray emissions from gas that has been heated by stellar explosions as well as outflows powered by our galaxy's central black hole. (MSNBC -- Technology)
Researcher Uses 100,000 Degree Heat To Study Plasma, What Happens To Matter Around Black Holes Sep 6, 2009
5, 2009) Using one of the greatest artificial sources of radiation energy, University of Nevada, Reno researcher and faculty member Roberto Mancini is studying ultra-high temperature and non-equilibrium plasmas to mimic what happens to matter in accretion disks around black holes. See also. (Science Daily)
Galactic cannibalism on our cosmic doorstep Sep 5, 2009
"The survey has produced an unrivalled panorama of galaxy structure which reveals that galaxies are the result of an ongoing process of accretion and interaction with their neighbours.". The scientists say that stars seen in the outermost reaches of the galaxy could not have formed as part of Andromeda itself because the density of gas so far from the galaxy s core would have been too low to allow formation to take place there. (Astronomy Now Online)
Dwarf Star Could Explode In Few Million Years Sep 4, 2009
Most likely, the white dwarf has grown to its unusual mass by stealing gas from its companion star, a process known as accretion. At 1. (Science Daily)
Tweeting Shooting Stars: World's First Mass Participation Meteor Star Party Aug 12, 2009
7, 2007) A team of European astronomers offer new evidence that high-mass stars could form in a similar way to low-mass stars, that is, from accretion of gas and dust through a disk surrounding the forming. . (Science Daily)
The Next Lunar Landing Jul 21, 2009
" There may be economic, scientific, or sentimental reasons attracting people to remote places; people always have a variety of reasons for moving from one place to another. One of the few constant factors in human history is migration, often over huge distances for reasons that are difficult to discern. I have little doubt that as soon as emigration from Earth becomes cheap enough for ordinary people to afford, people will emigrate. To make human space travel cheap, we will need advanced... (The Atlantic Online)
Turbulence Responsible For Black Holes' Balancing Act Jul 19, 2009
Turbulence generated by the jets mixes the hot and cool material together, which stabilizes further accretion and allows the cluster to perform its remarkable balancing act. (Credit: E. Scannapieco/ M. Brueggen / ASU Fulton High Performance Computing Initiative). (Science Daily)
Mapping a Star's Spots by Exoplanet Transits Jul 14, 2009
An alternative-in situ origin but this could upset some physics in hot, accretion disk models ... An alternative-in situ origin but this could upset some physics in hot, accretion disk models. (SkyAndTelescope.com)
New Portrait Of Omega Nebula's Glistening Watercolors Jul 9, 2009
7, 2007) A team of European astronomers offer new evidence that high-mass stars could form in a similar way to low-mass stars, that is, from accretion of gas and dust through a disk surrounding the forming. (Apr. (Science Daily)
Gamma rays burst from M87's black hole Jul 7, 2009
Like all black holes, it sucks material in from its surroundings, forming a tightly rotating accretion disc around the jaws of the monster. Immense gravitational energy propels material outwards as jets. (Astronomy Now Online)
Super-energetic Bursts Near Giant Black Hole Jul 3, 2009
Processes near this "accretion disk," powered by the immense gravitational energy of the black hole, propel energetic material outward for thousands of light-years. This produces the "jets" seen emerging from many galaxies. (Science Daily)
Magnetospheric Multiscale mission enters implementation phase Jun 19, 2009
It produces many intense phenomena from solar flares to auroras to high-energy cosmic rays to X-ray emissions from the accretion disks that surround the central regions of active galaxies to sawtooth oscillations in fusion plasmas. Closer to home, it is the ultimate driver of "space weather," which impacts technologies such as communications, navigation, power grids, and astronaut health and safety. (EurekAlert! -- Business News)
Planetary Preemies? Jun 18, 2009
Theorists expect the slow process of collisions and accretion to take about 10 million years for dust and rocks to collect into planets and clear away a protoplanetary disk. On the other hand, gravitational instabilities in the disk might act more quickly, forming a stellar-like companion such as a brown dwarf or a lower-mass object mimicking a conventional giant planet. (SkyAndTelescope.com)
> read more Jun 1, 2009
The planet probably formed from a collapsing gas cloud, like a star, rather than from the accretion of material inside a disk, like a planet. Artist's concept of the VB 10 system and the solar system, with all bodies drawn to scale. (SkyAndTelescope.com)
Discovery: Voracious cosmic eating machine May 31, 2009
"Accretion is a very messy process because of the magnetic fields that are involved," said study scientist Andrew Fabian of the University of Cambridge. lect> Add your comment (max {maxchars} characters) You must be logged in to leave a comment. (Florida Today)
Astronomers Pioneer New Method for Finding Exoplanets May 30, 2009
The planet probably formed from a collapsing gas cloud, like a star, rather than from the accretion of material inside a disk, like a planet. Whats really important about this finding is that after more than 50 years of efforts, it shows that the astrometry method can actually bear fruit. (SkyAndTelescope.com)
Astronomers Peer Into Black Hole's Edge May 28, 2009
The X-rays illuminate and are reflected from the matter before its eventual accretion ... "Accretion is a very messy process because of the magnetic fields that are involved," says Fabian. (Science Daily)
Black Hole Spotted in Middle of Feeding Frenzy May 28, 2009
"Accretion is a very messy process because of the magnetic fields that are involved," said study scientist Andrew Fabian of the University of Cambridge. Copyright. (Fox News)
Astronomers catch a star being revved-up May 23, 2009
right, streams onto accretion disk (white and blue) surrounding neutron star, left ... The material from the companion would form a flat, spinning "accretion disk" around the neutron star, blocking the pulsar's radio waves ... When observed again with optical telescopes in 2000, the system had shown clear evidence of an "accretion disk" around the neutron star. (EurekAlert!)
New light shed on pulsar puzzle May 22, 2009
The gas first swirls around the neutron star like water around a plughole, forming an "accretion disc" surrounding it ... Over the last decade, astronomers have discovered LMXBs that show an accretion disc stage, resulting in a rotating system that spits out X-ray pulses ... In 2000, the object seemed to possess an accretion disc of matter pulled from its companion star. (BBC News -- Science)
'Missing Link': Revealing Fast-spinning Pulsar Mysteries May 22, 2009
When observed again in 2000, the object had changed dramatically, showing evidence for a rotating disk of material, called an accretion disk, surrounding the neutron star ... "No other millisecond pulsar has ever shown evidence for an accretion disk," Archibald said ... "We know that another type of binary-star system, called a low-mass X-ray binary (LMXB), also contains a fast-spinning neutron star and an accretion disk, but these don't emit radio waves. We've thought that LMXBs probably are in... (Science Daily)
Spectacular Flaring In Extragalactic Jet From M87's Black Hole Apr 15, 2009
"I did not expect the jet in M87 or any other jet powered by accretion onto a black hole to increase in brightness in the way that this jet does," says astronomer Juan Madrid of McMaster University in Hamilton, Ontario, who conducted the Hubble study ... The rotational energy of the spinning accretion disk adds momentum to the outflowing jet ... The jet is powered by accretion onto a supermassive black hole, one of the most massive black holes yet discovered. (Science Daily)
Keep watching the skies Mar 27, 2009
Our observations of the universe tell us that stars gradually come together from this cosmic debris as random eddies and currents create clumps of matter that slowly pull more dust to them, and that the debris from this process undergoes its own accretion to form small and large planets. The computing cloud was created when the old internet, the one that supported dialup users and file transfer, went supernova with the arrival of fast broadband and smart devices. (BBC News -- Technology)
Erratic Black Hole Regulates Itself Mar 26, 2009
As the material swirls toward the black hole, an accretion disk forms ... These studies reveal that the jet in GRS 1915 may be periodically choked off when a hot wind, seen in X-rays, is driven off the accretion disk around the black hole ... This is evidence that the black hole is somehow regulating its accretion rate, which may be related to the toggling between mass expulsion via either a jet or a wind from the accretion disk. (Science Daily)
Super Sendoff for Planet-Hunting Kepler Mar 11, 2009
Folks should remember that the terrestrial planets formed closer to the Sun because of the heat in the accretion disk, Jupiter formed farther out because it was cooler so finding more hot jupiters does not help this paradigm but undermines the conventional story of our solar system's origin. Violation: lect> Additional Comments. (SkyAndTelescope.com)
Australia fires release huge amount of CO2 Feb 26, 2009
He said in the past, native forest carbon had been in rough equilibrium over millions of years with fires, with very small accretion of carbon over very long periods of time. "But then if you add rapid climate change and much greater fire frequency, the equilibrium carbon content of the native forests, instead of going up, is going to go down.". (Scientific American)
Turbulence May Promote Birth Of Massive Stars Feb 24, 2009
23, 2009) On long, dark winter nights, the constellation of Orion the Hunter dominates the sky. Within the Hunter s sword, the Orion Nebula swaddles a cluster of newborn stars called the Trapezium. (Science Daily)
A Supermassive Double Black Hole? Feb 8, 2009
The hot, bright accretion disk around each is about a couple hundred feet wide. The previous clear record-holder for tightest binary supermassive black hole involves two holes about 24 light-years apart, with an orbital period of about 150,000 years. (SkyAndTelescope.com)
