Core-collapse Supernovae
Supernovae can broadly be divided into two main categories depending on the type of progenitor star. Type Ia supernovae (SNIa) result from the explosion of a white dwarf which has exceeded the Chandrasekhar Limit.
A Collapse and then a Spectacular Explosion
The theory describing how gamma-ray bursts originate is called the "collapsar" model. Dr.
The collapse to a white dwarf takes place over tens of thousands of years, while the star blows off its outer envelope to form a planetary nebula.
Gravitational collapse in astronomy is the sudden inward fall of a massive body under the influence of the force of gravity.
Scientists want to know what led to the Maya's collapse. Finding clues 1,200 years after the fact is not easy. The area where Mayan cities once dotted the land is now filled with rain forest.
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gravitational collapse - Space and Astronomy Definition - Online Dictionary and Glossary Definition of gravitational collapse ...
COLLAPSE OF THE IRON CORE
Once the inner core begins to change into iron, our high-mass star is in trouble.
COLLAPSE
To fall down or fall to pieces.
COLLISION
A crash or forceful joining together.
Collapse of the World Trade Center
In 2002 the National Construction Safety Team Act mandated NIST to conduct an investigation into the collapse of the World Trade Center
World trade center ...
Collapse of the Wavefunction
In the Copenhagen interpretation of quantum mechanics, the result of an act of measurement, in which the potentialities inherent in the quantum wavefunction take on a specific value, namely, that which is measured.
collapse of protogalactic cloud
+ interactions/accretion of dwarf companions
Spiral structure :
seen in HI 21cm maps
seen in distribution of star formation regions
(seen in other galaxies)
arms follow star formation ---
brighter/bluer ...
collapse point
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Collapse Features
Some volcanic domes have steep scalloped margins. The outline of the scallops and the presence of debris aprons in places around the margins suggests that the scallops were formed by slope failure.
Collapse of mass in such a way that the mass maintains the symmetry of a cylinder. [LB90]
Azeotropic Mixture ...
the collapsed, extraordinarily dense, city-sized remnant of a high-mass star
new moon
the phase in which the moon is in the same direction as the sun in Earth's sky, so it is unilluminated and invisible ...
Core Collapse: Catastrophic gravitational infall of the center of a star when it no longer can generate sufficient pressure to maintain hydrostatic equilibrium.
As the collapse of a protostar is shrouded in obscuring dust and gas clouds observations need to take place in the infrared and radio regions.
Stellar collapse will generate black holes containing at least three solar masses. Black holes smaller than this limit can only be created if their matter is subjected to sufficient pressure from some source other than self-gravitation.
When the collapse reaches a critical density it stops. At this point, the matter in the star's core is packed so tightly that a block of its material the size of a sugarcube would weigh millions of tons.
The core collapsed very quickly from a size close to that of the Sun's to only about 20 km, so there is a gap in the support of the rest of the star. What support? - there is NO SUPPORT! Nothing is holding up the rest of the star.
The core collapse in the dying star releases a vast amount of gravitational potential energy, sufficient to blow away all the outer parts of the star in a violent explosion, and the star becomes a supernova.
After the collapse of Mycenae around 1100 BC, the Greek cities fell into decline and the country entered into a dark age such that the classical Greek alphabet reflects nothing of the Mycenaean syllabary.
As the core collapses, the outer layers have nothing to support them, and they collapse inwards, too. Once the density reaches about 1015 gm/cm3, the collapse is again halted. This is about the density of an atomic nucleus.
As the cloud collapses, it heats up and compresses in the center. It heats enough for the dust to vaporize. The initial collapse is supposed to take less than 100,000 years.
December 1 - Collapse of the Soviet Union: Ukrainians vote overwhelmingly for independence from the Soviet Union in a referendum.
December 4 - Journalist Terry A.
Gravitational collapse begins when a star has depleted its steady sources of nuclear energy and can no longer produce the expansive force, a result of normal gas pressure, that supports the star against the compressive force of its own gravitation.
GRAVITATIONAL COLLAPSE
Gravitational collapse is when an object in space (like an interstellar cloud of dust) collapses under its own weight.
Each protostar collapses very quickly; its gas falls inward in free fall. A protostar can collapse from a size equal to the outer diameter of the solar system to about 30 times the Sun's size (the size of Mercury's orbit) in about six months.
The collapsed core of a massive star. Stars that are very massive will collapse under their own gravity when their fuel is exhausted. The collapse continues until all matter is crushed out of existence into what is known as a singularity.
The monolithic collapse picture suggested by the results of ELS (and many subsequent ones) is appealing and explains the early appearance of some of the most massive galaxies.
A mass that has collapsed to such a small volume that its gravity prevents the escape of all radiation. Also, the volume of space from which radiation may not escape.
brown dwarf ...
A star that has collapsed to the point where it is supported against gravity by neutron degeneracy.
new moon - (n.)
The phase of the moon when the side of the moon facing the earth is the side that is not illuminated by sunlight.
gravitational collapse
When a massive body collapses due to its own mass. Gravitational collapse occurs in stars after the internal pressure cannot support the inward force of gravity.
gravitational collapse: The stage in the formation of a massive planet when it grows massive enough to begin capturing gas directly from the nebula around it.
Features such as collapse pits, which are known to be caused by dry ice sublimation, suggest that the ice cap is dissipating, adding gas to the martian atmosphere.
As the nebula collapses further, local regions begin to contract gravitationally on their own because of instabilities in the collapsing, rotating cloud ...
A solar filament collapsed on the Sun causing a CME to be released which struck on the 17th. A 12 hour geomagnetic storm took place and aurorae was seen.
Click here for an animation of the CME.
Click here for an image of the aurora.
sea divers and aviators caused by reduced atmospheric pressure and evolved gas bubbles in the body, marked by pain in the extremities, pain in the chest (chokes), occasionally leading to serve central nervous symptoms and neurocirculatory collapse.
Chandrasekhar limit (Imagine the Universe Dictionary - NASA GSFC) A limit which mandates that no white dwarf (a collapsed, degenerate star) can be more massive than about 1.4 solar masses.
It is what prevents further collapse of a neutron star. neutron star the collapsed core for an intermediate to high-mass star. The core is more than 1.4 solar masses but less than 3 solar masses and is about the diameter of a city.
[You may wonder why that collapse is so rapid, considering that Helmholtz and Kelvin--cited at the start of this section--found the gravitational energy of the Sun was sufficient to keep it hot for tens of millions of years.
The term "supernova" is derived from "nova" in that the supernova is vastly brighter, no matter that the mechanism of the core collapse of a supergiant is completely different from the mechanism of nova production.
The current paradigm for solar system origin suggests that its formation began with the collapse of part of an interstellar cloud of gas and dust, with an initial mass only 10 to 20 percent larger than the present mass of the Sun.
Evidence of subsurface ice prevails, especially in the form of petal-shaped ejecta blankets around some craters, vast areas of collapsed chaotic terrain, and so-called patterned ground at high northern latitudes.
There is good evidence that medium-sized black holes form as the corpses of massive stars which collapse at the end of their lives, and that supermassive black holes exist in the cores of many galaxies -- perhaps including our own.
This indicates that Jupiter has an internal source of energy - probably heat created by Jupiter's collapse when it was formed. By studying the infrared emission from Jupiter we can learn much about its cloud structure.
According to Jim Kaler's description of the theoretical predictions of second ascent in Stars, once core helium is used up in creating a huge ball of carbon and oxygen, the star will collapse inward again.
The core cools, drawing heat from its surroundings to power the fusion; the outward radiative pressure, which had supported the star for many millions of years, ceases and the star undergoes free fall gravitational core collapse until it reaches ...
When a really massive star runs out of nuclear fuel in its core the core begins to collapse under gravity. When the core collapses the entire star collapses. The surface of the star falls down unti l it hits the now incredibly dense core.
When a star like our Sun dies, it swells up once into a red giant, and then, it finally collapses into a white drawf.
Neptune and Uranus are small enough to have lost all of the energy liberated at their cores through gravitational collapse since their formation four and a half billion years ago.
A mine collapse in Germany in 1989, as well as a collapse in Russia in 1995 and another in the USA in the same year, originally looked disturbingly like nuclear bomb tests.
An important process in the initial stage of star formation whereby clumps of a molecular cloud uncouple from the interstellar magnetic field, which would otherwise resist the further gravitational collapse of the clumps.
After enough iron in the core is accumulated, within one hundredth second, the inner core collapses and heats up dramatically. All fuel, if not burnt up yet, will fuse to iron and nickel. The outer core will also collapse with the inner core.
In 2364, the SS Tsiolkovsky was observing the collapse of a red giant into a white dwarf when the gravitational influence of the star caused an outbreak of polywater intoxication that claimed the crew.
At the end of its life, a giant star collapses and shrinks. Its mass gets more and more compressed until it is so thick that light can’t escape from it because so much material has been crammed into a small space.
A star is born when an enormous cloud of hydrogen gas collapses until it is hot enough to burn nuclear fuel (producing tremendous amounts heat and radiation).
The bright part of the nebula is the glow of many luminous, newborn stars shining on the surrounding gas cloud that they collapsed from. The most important part of the Orion Nebula is the part we can't see: the opaque Orion Molecular Cloud.
This is because the heavier elements act as "cooling agents," helping to radiate away the heat of gas clouds in this medium, which can then collapse to form stars.
All black holes will eventually collapse. Steven Hawking demonstrated that all black holes should emit black body radiation. This radiation is actually a loss of mass.
 See also: Time, Light, Earth, Second, Mass
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