Types Of Supernova    

                                    Type II Supernovae

A humongous stellar explosion, a supernova, may be brighter than an entire galaxy for a brief time. It may be silent, but it sure is bright! The light that travels away from a supernova can be read by specialized detectors here on Earth to produce a spectrum, which for this lesson's purposes can be remembered as an arrangement of colors in order of wavelength.

A spectrum may have added or missing lines of colors that clue astronomers into the different compositions of matter from which the lights came or passed through. And by 'composition,' I mean the stuff the star is made of. It's like a barcode on a product label that tells a machine what the product actually is. In our case, when a massive star is days away from a supernova explosion, it is composed of a lot of different things, from hydrogen at the very outer layers to iron at its very core.
Most stars that are eight or more times the mass of our sun die as a Type II Supernova. A Type II Supernova is a supernova that is classified as having hydrogen lines in its spectra that are made by the explosion of a very large star. The hydrogen lines come from the hydrogen-rich outer layers of the star as the star explodes.

                                      

                    Type Ia Supernovae

But there are other kinds of supernovae. A Type I Supernova is a kind of supernova with no hydrogen lines in its spectrum. How can this occur if I just said that the outer layers of the star are rich in hydrogen? Well, there are two ways. The first is a supernova explosion that results from the collapse of a white dwarf, termed a Type Ia Supernova. A white dwarf is a remnant of a star that wasn't massive enough to force the ignition of carbon fusion for energy.

To understand how a Type Ia Supernova occurs, you also need to know a term called the Chandrasekhar Limit. The Chandrasekhar Limit is equal to about 1.4 solar masses, and it tells us that all stable white dwarfs must be smaller than 1.4 solar masses. This means stars more massive than 1.4 solar masses can only become white dwarfs if they shed mass as they evolve, and we know this does occur and helps to explain why medium mass stars upwards of eight solar masses can become white dwarfs.

                              Super Nova

    

Where Do Supernovas Take Place?
Supernovas are often seen in other galaxies. But supernovas are difficult to see in our own Milky Way galaxy because dust blocks our view. In 1604 Johannes Kepler discovered the last observed supernova in the Milky Way. NASA’s Chandra telescope discovered the  

remains of a more recent supernova. It exploded in the Milky Way more than a hundred years ago.

What Causes a Supernova?
A supernova happens where there is a change in the core, or center, of a star. A change can occur in two different ways, with both resulting in a supernova.

The first type of supernova happens in binary star systems. Binary stars are two stars that orbit the same point. One of the stars, a carbon-oxygen white dwarf, steals matter from its companion star. Eventually, the white dwarf accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova.

The second type of supernova occurs at the end of a single star’s lifetime. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova. The sun is a single star, but it does not have enough mass to become a supernova.

Why Do Scientists Study Supernovas?
A supernova burns for only a short period of time, but it can tell scientists a lot about the universe.

One kind of supernova has shown scientists that we live in an expanding universe, one that is growing at an ever increasing rate.

Scientists also have determined that supernovas play a key role in distributing elements throughout the universe. When the star explodes, it shoots elements and debris into space. Many of the elements we find here on Earth are made in the core of stars. These elements travel on to form new stars, planets and everything else in the universe.

How Do NASA Scientists Look for Supernovas?
NASA scientists use different types of telescopes to look for and study supernovas. Some telescopes are used to observe the visible light from the explosion. Others record data from the X-rays and Gamma-rays that are also produced. Both NASA’s Hubble Space Telescope and Chandra X-ray Observatory have captured images of supernovas.

In June 2012, NASA launched the first orbiting telescope that focuses light in the high-energy region of the electromagnetic spectrum. The NuSTAR mission has a number of jobs to do. It will look for collapsed stars and black holes. It also will search for the remains of supernovas. Scientists hope to learn more about how stars explode and the elements that are created by supernovas.

What Can You Do to Help?
You do not have to be a scientist, or even have a telescope, to hunt for supernovas. For example, in 2008 a teenager discovered a supernova. Then in January 2011, a 10-year-old girl from Canada discovered a supernova while looking at night sky images on her computer. The images, taken by an amateur astronomer, just happened to include a supernova.

With some practice and the right equipment, you could find the next supernova!

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Words to Know

white dwarf: a star near the end of its life that has used most or all of its nuclear fuel and collapsed into a size similar to Earth

                                        Super Nova

A supernova is an astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion. For a short time, this causes the sudden appearance of a 'new' bright star, before slowly fading from sight over several weeks or months.

how is super nova created

A supernova happens where there is a change in the core, or center, of a star. A change can occur in two different ways, with both resulting in a supernova.

The first type of supernova happens in binary star systems. Binary stars are two stars that orbit the same point. One of the stars, a carbon-oxygen white dwarfs, steals matter from its companion star. Eventually, the white dwarf accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova.

The second type of supernova occurs at the end of a single star’s lifetime. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova. The sun is a single star, but it does not have enough mass to become a supernova.

A supernova happens where there is a change in the core, or center, of a star. A change can occur in two different ways, with both resulting in a supernova.

The first type of supernova happens in binary star systems. Binary stars are two stars that orbit the same point. One of the stars, a carbon-oxygen white dwarf, steals matter from its companion star. Eventually, the white dwarf accumulates too much matter. Having too much matter causes the star to explode, resulting in a supernova.

The second type of supernova occurs at the end of a single star’s lifetime. As the star runs out of nuclear fuel, some of its mass flows into its core. Eventually, the core is so heavy that it cannot withstand its own gravitational force. The core collapses, which results in the giant explosion of a supernova. The sun is a single star, but it does not have enough mass to become a supernova.

            what is super nova made up of?

The brilliant point of light is the explosion of a star that has reached the end of its life, otherwise known as a supernova. Supernovas can briefly outshine entire galaxies and radiate more energy than our sun will in its entire lifetime. They're also the primary source of heavy elements in the universe.

I'll need to talk about what causes a supernova, because it is somewhat relevant here. Stars live out their lives by burning (via nuclear fusion reactions) light elements like hydrogen into heavier elements like helium in their core. For a star like the sun, this process will go on for about 10 billion years before it runs out of fuel. More massive stars have more fuel to burn, but they go through it much more rapidly, so they actually live shorter lives. When a star runs out of hydrogen, it will try to burn helium into even heavier elements, like carbon, nitrogen, and oxygen. If those elements sound familiar, they should. You're a carbon-based lifeform, and you're breathing nitrogen and oxygen as we speak. All of those materials came from the core of some ancient star that exploded and spread its materials around the galaxy, before the Sun and the Earth were even formed! The cartoon on the right shows a deuterium nucleus combining with a tritium nucleus to for an alpha particle (and a stray neutron). Alpha particles are the nuclei of helium atoms, and can be combined with other particles to form all the elements that we commonly see around us.

                        super nova 'effects'

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A supernova is a star explosion – destructive on a scale almost beyond human imagining. If our sun exploded as a supernova, the resulting shock wave probably wouldn’t destroy the whole Earth, but the side of Earth facing the sun would boil away. Scientists estimate that the planet as a whole would increase in temperature to roughly 15 times hotter than our normal sun’s surface. What’s more, Earth wouldn’t stay put in orbit. The sudden decrease in the sun’s mass might free the planet to wander off into space. Clearly, the sun’s distance – 8 light-minutes away – isn’t safe. Fortunately, our sun isn’t the sort of star destined to explode as a supernova. But other stars, beyond our solar system, will. What is the closest safe distance? Scientific literature cites 50 to 100 years as the closest safe distance between Earth and a supernova. Follow the links below to learn more

                                       

FACTS AND VIDEOS ON BLACK HOLES

Black Hole Facts.

Fact 1: You can’t directly see a black hole.

Because a black hole is “black” , no light can escape from it, it’s impossible for us to sense the hole directly through our instruments, no matter what kind of radiation we use (light, X-rays, whatever.) The key is to look at the hole’s effects on the nearby environment, points out NASA. Say a star happens to get too close to the black hole, for example. The black hole naturally pulls on the star and rips it to shreds. When the matter from the star begins to bleed toward the black hole, it gets faster, gets hotter and glows brightly in X-rays.

Fact 2:Our Milky Way has a black hole.

Although there is probably a huge super-massive black hole lurking in the middle of our galaxy. Luckily, we’re nowhere near this milky way we are about two-thirds of the way out from the center, relative to the rest of our galaxy ,but we can certainly observe its effects from afar. For example: the European Space Agency says it’s four million times more massive than our Sun, and that it’s surrounded by surprisingly hot gas.

Fact 3: Dying stars create stellar black holes.

 Our Sun is going to end its life quietly; when its nuclear fuel burns out, it’ll slowly fade into a white dwarf. That’s not the case for far more massive stars. When those monsters run out of fuel, gravity will overwhelm the natural pressure the star maintains to keep its shape stable. When the pressure from nuclear reactions collapses, according to the Space Telescope Science Institute, gravity violently overwhelms and collapses the core and other layers are flung into space. This is called a supernova. The remaining core collapses into a singularity — a spot of infinite density and almost no volume. That’s another name for a black hole.

Fact 4: The nearest black hole is 1,600 light-years away.

An erroneous measurement of  Sagitarii led to a slew of news reports a few years back saying that the nearest black hole to Earth is astoundingly close, just 1,600 light-years away. Not close enough to be considered dangerous, but way closer than thought. Further research, however, shows that the black hole is likely further away than that. Looking at the rotation of its companion star, among other factors, yielded a 2014 result of more than 20,000 light years.

Fact 5: Black holes are used all the time in science fiction.

There are so many films and movies using black holes, for example, that it’s impossible to list them all. Interstellar‘s journeys through the universe includes a close-up look at a black hole. Event Horizon explores the phenomenon of artificial black holes something that is also discussed in the Star Trek-universe. Black holes are also talked about in Battle star: Galactica, Stargate and SG1.

Bibliography

 

1)https://youtu.be/Ll-4OLrNZLQ

2)http://space-facts.com/black-holes/

3)http://www.universetoday.com/46687/black-hole-facts/

4)http://wikipedia.en/ 

5)https://youtu.be/5d9PLK7X1-4

 

What is inside a black hole?

We cannot glimpse what lies inside the event horizon of a black hole because light or material from there can never reach us. Even if we could send an explorer into the black hole, he/she could never communicate back to us. 

THIS IS THE PICTURE OF A SUPER MASSIVE BLACK HOLE

Current theories predict that all the matter in a black hole is piled up in a single point at the center, but we do not understand how this central singularity works. To properly understand the black hole center requires a fusion of the theory of gravity with the theory that describes the behavior of matter on the smallest scales, called quantum mechanics. This unifying theory has already been given a name, quantum gravity, but how it works is still unknown. This is one of the most important unsolved problems in physics. Studies of black holes may one day provide the key to unlock this mystery. 

Einstein's theory of general relativity allows unusual characteristics for black holes. For example, the central singularity might form a bridge to another Universe. This is similar to a so-called wormhole (a mysterious solution of Einstein's equations that has no event horizon). Bridges and wormholes might allow travel to other Universes or even time travel. But without observational and experimental data, this is mostly speculation. We do not know whether bridges or wormholes exist in the Universe, or could even have formed in principle. By contrast, black holes have been observed to exist and we understand how they form.