There was a star somewhere around the sky staying almost unnoticeable, and got burst out suddenly in to a blistering brightness; it's just a one more Supernova!--if not Nova.
The energy and light that was radiated in to the sky during the star's sudden outburst is so heavy that it can easily outshines the entire galaxy--for several weeks to several months depending on the star's mass-- where it resides in, and that happens every time. The energy that got released during the process equals the entire energy that our sun can generate in its entire lifetime.
The star explodes and expels the material it was hiding till then, in to the surrounding Interstellar medium at a velocity of up to 30,000 km/s(10% that of light's). The material thus got released expands taking the help of a Shock wave that was generated during the sudden explosion, in the form of gas and dust called a Supernova remnant.
Supernova happens very rare compared with Nova, which is a completely different process and happens very often. For a galaxy in the size of our Milky way, supernova happens just once in every 50 years. Anyways, it's a lot more common process and happens once in every sec, when we look through the entire universe(as the universe breeds stars every sec and they are not eternal).
It's not that every star that exists in the universe can eventually turn in to a Supernova, but is entirely depends on the mass of the star. A star that which reaches a mass that is greater than 1.4 times that of our sun's, at the end of it's fuel consumption, will explode in to a Supernova. And that 1.4 limit was found by Chandrashekar and hence named after him as Chandrashekar limit.
Our sun according to chandrashekar can't turn in to a supernova but will end up as a
White dwarf, when it gets completely devoured of its fuel. And even no possibility of forming a Nova or Supernova later on as there is no binary neighbor, close by.
There are two types of supernova and I will try to explain them in my next post. :)
As I understand, a supernova is about 1000 times stronger than a nova. But what is a nova? Is that a 'weak' supernova ?
ReplyDeleteThe article you posted says: "This process is akin to a nova, where matter, mainly hydrogen, falls onto a star, slowly building up and then exploding, but with less force then a full-fledged supernova. " What's causing you trouble with that definition?
ReplyDeleteMy puzzle is that the very definition above describes a supernova type I, so what is a nova that is one thousandth the strength of a supernova? By the way, before reading this article, you knew that definition of a nova?
ReplyDeleteThere isn't really much in common between a nova and a supernova other than they make a star brighter (nova = new star) A nova is where some material falls onto the surface of a compact star which makes it 10-100% brighter for a short time - but the star isn't really affected. A supernova is the end of life of a large star where it runs out of fuel in the core and there is no reaction to support the rest of the star. The entire star collapses and creates more energy in a few minutes than the star generated in the 10bn years of it's life. There is only a small bit of the star left afterward s a neutron star
In a nova, hydrogen from a nearby star falls onto a white dwarf star until it ignites and blows off in an expanding shell. Essentially, a white dwarf turns back into an ordinary star for some weeks. In a Type I supernova, enough material falls on this white dwarf to destroy it, turning it into a neutron star.
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