Can anyone explain me when do scientist see the supernova...?

Question

Can they see it in the moment when it is happening or later? When the star is thousand years light away, does this mean that it has happened (supernova) a lot of time ago and they realize it only now?
I am ignorant in this field and I would like to learn, simple and clear explanation please! Thanks

Answer 1

:)

Ur funny,

sure everything u see is the light hitting Ur retina, ligth travels,

300000km, sec,

when u look at the sun u see the sun 8,3 minutes, ago,

if the sun would stop to exist, by some kida miracle, u would still see it shine for 8 minutes,

same with supernova or anything we see true a telescope, we see the light that reaches us, that left, milions, or billions of years ago,

Answer 2

NASA reported that supernova SN 2006gy, had been discovered, 2 days ago though they had been studying it for about 8 months previously. See story below.

It was a big one. 150 times the mass of the sun. Though such massive stars werre common in the early days of the universe, they are much rarer these days,

"Of all exploding stars ever observed, this was the king," said Alex Filippenko, leader of the ground-based observations at the Lick Observatory at Mt. Hamilton, Calif., and the Keck Observatory in Mauna Kea, Hawaii. "We were astonished to see how bright it got, and how long it lasted."

The star that produced SN 2006gy apparently expelled a large amount of mass prior to exploding. This large mass loss is similar to that seen from Eta Carinae, a massive star in our galaxy, raising suspicion that Eta Carinae may be poised to explode as a supernova.

Although SN 2006gy is intrinsically the brightest supernova ever, it is in the galaxy NGC 1260, some 240 million light years away. However, Eta Carinae is only about 7,500 light years away in our own Milky Way galaxy.

"We don't know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case," said Mario Livio of the Space Telescope Science Institute in Baltimore, who was not involved in the research. "Eta Carinae's explosion could be the best star-show in the history of modern civilization."

As SN 2006gy is 240 million light years away light from it takes 240 million years to get here. So when the astronomers noticed the supernova in August 2006 the event they were observing had already taken place, 240 million years ago, about one twentieth of the time that our Sun has existed.

If Eta Carinae explodes it would the moment we noticed it, be an event that had already taken place 7,500 years previously. Less of a time lapse because it is nearer to us.

Nearer still is the possibility that Betelgeuse, a red giant in Orion might become a supernova. It is a mere 427 light years away,

Answer 3

They Or We See It Only After The Light Of Supernova Travels To us.
So If it is ! Million Light Years Away, We Will See It Only after A million Years Since The Event

Answer 4

I do not think that you are ignorant on the subject...let's say novice instead. However, you got it right when Astronomers ( or anyone else for that matter sees a supernova that was not there previously, the kight from the original explosion is just then reaching Earth. The distance in light years that the former star was from earth will tell you how long ago the in years the explosion occurred.

See Astronomy is pretty easy and a lot of fun

Answer 5

it all depends on the distance between the explotion and earth. i can make you understand clerly with an example and here it goes.Recently a gargantaun star ripped apart a star perhaps 150 times massive than our sun in a relatively near galaxy in the most powerful and brightest supernova.
it occured 240 million light years away in a galaxy called NCG 1260.
the explotion occured a year ago but we could see it only last september.that was because it took light that gap of time to reach earth.light travels at the speed of 30,00,00,000metres per second.