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Novas
Supernovas and Novas are terms to describe the massive explosion of a star that has reached the end of its life.
357 Questions
What elements were not formed inside stars?
Scientists believe that the "Big Bang" generated mosly hydrogen, with a little helium and traces of lithium (the next heavier element) and vanishingly small amounts of anything heavier. Anything heavier was formed by nuclear fusion in the cores of stars.
But in order for an atom to be here on Earth our out in space, it had to get OUT of the star. And about the only way for large quantities of matter to get out of a star is for the star to have exploded in a nova or supernova explosion.
So every atom of matter here on Earth - including every atom of carbon or iron in your bodies - was created in the core of a long-dead star.
Is this true Intermediate mass stars expand in red giants and then become part of a supernova?
No. Intermediate mass stars will evolve into Red Giants and then to White Dwarfs.
See related questions for more information.
Dangerous.
Novas, or supernovas. Tycho Brahe coined the phrase "nova stellarum" when a "new star" appeared in the night sky. We now know that he was observing a supernova, the death throes of a very massive star.
How bright was the crab nebula?
from sci-tech encyclopedia http://content.answers.com/main/content/img/McGrawHill/Encyclopedia/images/CE166300FG0010.gif The Crab Nebula is the remnant of a tremendous stellar explosion witnessed by Chinese astronomers in 1054. The explosion, called a supernova, occurred at a distance of about 2000 parsecs from the Earth (1 parsec = 1.9 × 1013 mi = 3.1 × 1013 km = 3.26 light-years). The Crab now consists of three components. At the heart of the nebula is what is left of the core of the Crab's giant stellar progenitor. This neutron star has twice the mass of the Sun concentrated into an object only about 20 km (12 mi) across, giving it a density of 109 tons per cubic centimeter. The neutron star is spinning at 30 times a second, whipping its powerful (108 tesla) magnetic field around with it. Radiation formed in this extreme environment is concentrated into two intense beams directed away from the neutron star's two magnetic poles. As these beams sweep past the direction of the Earth like the beam from a lighthouse, the star appears to wink on and off, earning it the name "pulsar." The Crab pulsar has been seen in all parts of the electromagnetic spectrum from gamma rays through radio waves. The Crab pulsar's rotational period is slowing by 34 nanoseconds a day, and as it slows it loses 100,000 times more power than is radiated away by the Sun. Most of this energy is carried away from the pulsar by a wind of electrons and positrons moving at close to the speed of light. The wind feeds a vast cloud of highly relativistic particles. This cloud is called the Crab synchrotron nebula because, as the particles spiral through the nebula's magnetic field, they give off the sort of radiation emitted by a synchroton particle accelerator. . The third component of the Crab is a complex of filaments made up of gas ejected by the explosion itself (see illustration). The filaments are ionized by ultraviolet radiation from the synchrotron nebula, causing them to glow like the gas in a fluorescent light bulb
Why is iron the heaviest element that can be produced by star?
It isn't; heavier elements can be, and are, produced by DYING stars.
The reason is the "packing fraction curve". As atomic nuclei would fuse together within the cores of normal stars, hydrogen atoms as "fuel" would fuse into helium "ash"; when the star became old, the core of the stars would heat up and become more dense as the star began to collapse into itself. The denser stellar core material would heat up and begin to fuse into heavier elements; carbon, oxygen, and heavier elements, releasing a little energy every time a new atom was formed by fusing together lighter ones - UNTIL they got to iron.
Once you get to iron, any additional fusion sucks energy OUT of the star's core, and every fusion from there on sucks even MORE energy out of the star, leading to the star's quick collapse. This is one scenario for how a "nova" might occur.
If a star EXPLODES in a supernova, then there's LOTS of energy to crash even heavy elements together into even HEAVIER elements. So all of the gold, uranium, lead, and every atom heavier than iron, was formed in a supernova explosion.
Do all stars that become supernovae leave behind a neutron star?
No. The most massive stars will leave behind a black hole.
What is the relationship between the words supergiant supernova neutron star and black hole?
They are all astronomical terms for stars or star related.
What determines whether a star eventually becomes a black dwarf or a neutron star?
The stars solar mass, or relative size to the sun. If its gravity is big enough, when it does condense in on itself, it will create a black hole. If not, it will form a highly dense clump of matter, or a Neutron Star If the stars mass is more than 3 solar masses, it will form a black hole. If it is less, it will form a neutron star
What is the order from smallest to largest sun supernova red giant white dwarf?
White Dwarf, Sun, Red Giant, Supernova
What is the relationship between a supernova and a neutron star?
They both explode and some parts turn to meteors and some land on Earth.
Though through out the whole thing people think super novas are alien spaceships from another galaxy. Astronomers study these novas and tell us the truth!
The density of a white dwarf is?
It varies, but it is several tons per cubic centimeter - i.e., millions of times as dense as water.
I suppose that there are, now, since Google caches everything. However, these terms have not been used before, and provide no more significant information than "supernova".
What is a guest star was that seen exploding over China in the year 1054?
A "guest" star is the name for the original star, before it exploded as a Supernova. Because the Supernova is the explosion and has no real physical relation to the Star, it is termed "guest" star.
Can you see a star explode in your lifetime?
Yes. Supernova explosions are visible to the naked eye on average of once per century. In the 1054 AD, a "new star" or "nova stellarum" was observed to be visible in the daytime. These days, we call it the "Crab Nebula". It is entirely possible that a supernova could explode and be visible in your lifetime, although that would probably mean that it has ALREADY exploded and the light is on its way even now.
However, it would be (so far!) impossible to predict such an event ahead of time.
A supernova explosion releases unbelievably titanic energies. We wouldn't want one to explode within several hundred light years of us!
Why a stars collapses when iron is the only element left in the core?
When hydrogen fuses into helium, extra energy is released, causing more fusion. When helium fuses into carbon, extra energy is released, causing the reaction to continue. When each element fuses into heavier ones, energy is released - until you get to iron.
When iron fuses into heavier elements, or when anything fuses into elements heavier than iron, it sucks energy OUT of the reaction, slowing it down. This is like poison to a nuclear reaction; sucking the energy OUT of a star rather than releasing it. The star dies instantly, and the collapse causes a titanic explosion in which even MORE energy is sucked out of the core of the star, as heavy elements fuse into heavier ones, until the heavy elements like Uranium and thorium are so massive that they cannot hold together and begin to fall apart.
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The above answer isn't exactly right. An over simplification.
Normal stars, like our sun, live just long enough to begin fusing helium into carbon. At that stage, they generate so much energy that they essentially boil off their outer layers, in a stellar nova. Eventually they boil off everything but their inner carbon core, leaving a white dwarf. But giant stars, like Betelgeuse, have enough mass to hold together. This mass, and the immense force at the stars core, provides enough energy to fuse carbon into heavier elements.
Nuclear fusion is not easy. So far we have only achieved it through a two step reaction, beginning with a nuclear fission explosion. You have to put energy in to get energy out. The reason is the electromagnetic charge of the atomic nucleus. The nucleus is made of positively charged protons and neutrally charged neutrons. It takes a lot of force to overcome these charges. The bigger the nucleus, the more force required to fuse it.
So, after fusing all of its available helium into carbon, the star is on borrowed time. Each stage in the star's fusion cycle is shorter than the last, simply due to the availability of the fuel. After billions of years of fusing hydrogen, millions of fusing helium, time quickly runs short. Carbon fusion last about 600-1000 years. Carbon fusion produces neon, neon fusion lasts roughly 1 year. Next is oxygen fusion, lasting maybe 6 months, producing silicon. But then, something strange happens. In every previous step of the fusion cycle, fusion produces more energy than it consumes, but iron is the other way around. Silicon fusion produces iron, but iron fusion requires too much energy, effective ending all nuclear fusion at the core. Silicon fusion lasts 3-5 days, and at that time there is not enough energy left in the core to fuse anything, and the core collapses under the weight of the stars mass. This collapse goes until protons an neutrons are crushed together so tight the the entire mass becomes pure neutrons. This stops the collapse momentarily, sending enormous shock waves through the stars outer layers, causing massive runaway nuclear reactions, blasting the star apart in a type II super nova. The runaway nuclear reactions produce elements heavier than iron through neutron accumulation. At the core, one of two things happens: Either the nuclear forces stop the collapse, forming a neutron star, or the force of the collapse overpowers the nuclear forces, and the core collapses into a black hole.
On a related note, the star Betelgeuse, mentioned earlier, is a red super giant, and is believed to be rapidly supernova. In fact, given its distance of over 800 light years away, it is likely that it already has gone supernova. When it does, or rather when the supernova's light reaches earth, it will outshine even the full moon in the night sky, and be easily visible in broad daylight. The supernova will last about 6 mouths, before fading away for good. It should produce a neutron star.
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The above statement "Nuclear fusion is not easy. So far we have only achieved it through a two step reaction, beginning with a nuclear fission explosion." is not completely true, referring to the "so fare we have only" part. We have achieved cold fusion by using super conducting magnets to drive hydrogen particles into each other. They reach speeds near light speed, then clash into each other. If the collision is direct enough they will fuse into helium. This produces far more energy than the energy used to crash them into each other. Once we find a way to harvest that energy we can create cold fusion reactors.
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Well, just a small addition. Fusion has been accomplished with lasers also. Work at the National Ignition Facility Lawrence Livermore Laboratories, has produced small fusion reactions and they hope to create a sustained reaction at some point.
What could cause a noisy fifth gear on a 1999 Yamaha 650 v star?
Hello. Are you sure it is 5th gear making the noise? The noise is quite possibly a dry and very worn coupling which connects the drive shaft to the pinion shaft in the differential. Yamaha does not put enough grease an this coupling at the factory. Folks think that driveshafts are maintenance free and don't think to check this joint. My wife's 2002 V star 650 Classic experienced a driveline failure at 11,000 miles. The coupling wore down and eventually stripped the splines from the pinion shaft. You can't buy a new pinion shaft, or even a ring and pinion set. The only repair is to order an entire new differential assembly (about $600, as of 12/22/06). Unlike an automobile, which uses a yoke and u-joint to connect the driveshaft to the rear of the transmission and another to connect the diveshaft to the rear pinion shaft, most shaft driven motorcycles only employ a yoke and u-joint arrangement where the driveshaft connects to the transmission. Most modern bikes also have enclosed driveshafts, which are great at keeping things contained, uncontaminated, and lubed. I have a Yamaha Virago 535, a VMax, a 1981 XJ650 Midnight Maxim, and a Royal Star Venture, which have enclosed shafts. No problems at all with those bikes. However, the V Star series utilizes a design that employs an "open type" driveshaft. You can see about a foot long section of the driveshaft spinning as the bike is moving. The design uses a coupling which allows a little necessary movement between the splined rear end of the driveshaft and the splined area of the pinion shaft. The coupling looks like a 3 inch piece of pipe which has splines on the inside. The rear of the coupling slides over the pinion shaft and the driveshft slides into the coupling from the front end. There is a shock spring located in the end of the pinion to keep the driveshaft from slamming into it as the suspension of the bike moves up and down during normal operation. During any rear wheel removal the entire rear differential and the driveshaft must be removed as one unit. Sounds complicated, but in reality, it is a very, very easy process. When the assembly is removed, it only takes a minute to remove the four acorn nuts from the forward housing of the assembly, slide the housing up the driveshaft and inspect the coupling for proper lubrication. Even if you have to grease the coupling joint, it should only take about five minutes to disassemble the housing, grease the area, and reassemble it. The problem is that most folks don't think about it. The design of the differential causes you to think that the front housing is lubricated from the differential fluid. However, it is a totally separate area and requires a moly type grease for the coupling. I have been my own car and motorcycle mechanic for about 35 years and even I didn't think about inspecting that area (until it failed). Now (as well as feeling embarassed) I'm spending big bucks for the part, which I hope gets here soon. I'm just glad the parts failed about a mile from home and not while we were on a trip to another state. I would hope that you take the time to inspect your differential. While you are at it, take a few minutes to inspect your wheel spokes for tightness. The V Star rear wheel seems to like to loosen its spokes every so often. If any need adjusting, make absolutely sure to tighten them in the proper sequence or you will pull the wheel out of round. A spoke torque wrench is a valuable tool to use for this. Good luck.
What are the byproducts of Supernovae?
All the elements of the periodic table apart from hydrogen and helium are synthesised in the explosion of a supernova.
What is the temperature of a white dwarf star?
A white dwarf star's temperature can range from approximately 7000K to 19000K.
Well the Disney movie ends with Stanley Yelnats and Zero Getting the gold and becoming rich and zero finds his mother =) hope that is what u were asking
Stanley finds the treasure with his name on it and Mr.Sir and the warden try to take it from him. when he gets home they share it with his family and his friend zero. zeros mom finds him and takes him homeWhat effect does gravity have on a white dwarf?
science we can not step foot on a white dwarf and it's in space i say nothing the gravity does nothing
Is a supernova more luminious than a nova?
An object further away will appear less bright than the same object closer to us.
However, a supernova can emit the same brightness as our Sun does in it's whole lifetime, in a very short period of time - a nova on the other hand, at maximum brightness is only about 100,000 times that of the Sun.
Why can scientists see a star explode but cannot hear it?
Sound waves cannot propagate through the vacuum of space. Scientists observe explosions of stars through telescopes that detect different forms of electromagnetic radiation, such as light, X-rays, and gamma rays. These observations provide valuable information about the event, even though sound waves are not involved.
What remnant does a supernova leave?
Depending on the mass of the original star, it is either a black hole or a neutron star.
