MELISSA BLOCK, host: There's a rare astronomical event going on - a cosmic explosion that is so close and so bright, you can see it with a pair of good binoculars. It is a supernova in its infancy and it was discovered last month by astronomer Peter Nugent, senior scientist at the Lawrence Berkeley National Laboratory.
He joins me now to talk about his discovery. Welcome to the program.
PETER NUGENT: Thank you for having me, Melissa.
BLOCK: And first, what exactly is a supernova, the kind that you discovered here?
NUGENT: So the kind that I discovered is called a type 1A supernova. It's the death of a star. This is a massive explosion. This star started off a few times bigger than our sun. It burned all of its hydrogen to helium, helium to carbon and oxygen, and then it was just sitting there. This star is about the size of the planet Earth, but weighs about 1.4 times the mass of our sun when it's done all this burning.
And then it has a companion, in this case. We know that because otherwise, it would just sit there and glow and cool down and that would be the end of it. The companion feeds it with more mass and the temperatures and pressures build up on the inside to the point you have one of the largest thermonuclear explosions in the universe.
BLOCK: And that explosion is the supernova. How did you find it?
NUGENT: We run a survey called the Palomar Transient Factory and every single night, we take digital images of most of the visible sky and then we sort through everything that we find to look for these sort of needles in a haystack.
BLOCK: So you're looking for something that wasn't there before, in other words?
NUGENT: Exactly. Something that - boom - pops up out of nowhere.
BLOCK: And when you saw this boom pop up out of nowhere, did you know exactly what you were seeing?
NUGENT: No. At first, I actually thought, because I could see that it was in this very nearby galaxy called the Pinwheel Galaxy, I, at first, thought it was an asteroid that just happened to cross between us and it and that it would move in the next image that I looked at. And - it was still there, so I went back and I looked at all the data we had ever taken on this and nothing had ever been seen there before.
So that's when I got excited and that's when I alerted the collaboration to, hey, I think we've got something good here.
BLOCK: Peter Nugent, when we say this supernova is especially close, how close is it?
NUGENT: It is 21 million light years away, which may sound far, but in fact, is very, very close for a supernova. We find one to two supernovae a night and they're typically at a billion light years away.
BLOCK: And how bright is this that you can see it with good binoculars?
NUGENT: In astronomical terms, it's 10th magnitude. That turns out to be about one one-hundredth as bright as the human eye can see unaided, but with a pair of binoculars or even a six-inch telescope, you can see this quite easily in a dark sky.
BLOCK: What would you be seeing? What does it look like?
NUGENT: The Pinwheel Galaxy is a fuzzy spot. It looks like a little cloud and the supernova there is brighter than all the rest of the stars combined in the Pinwheel Galaxy.
BLOCK: So for people who are inspired by listening to this and want to go out and try to find this supernova - and they have to act pretty fast, right? Because it's not going to be around for long, not going to be visible for long.
NUGENT: It's not going to be around for long. The best time will be next week after the full moon, which is the 12th. And the Big Dipper where this supernova is located, just off the last two stars in the handle, that'll be at its highest point just after sunset.
BLOCK: And you go to the constellation, you go to the Big Dipper and then what do you do?
NUGENT: You swing to the last two stars in the Big Dipper and you make an equilateral triangle with the point headed north and it's right there at the other end of the equilateral triangle. And you can also look up online, there are many star charts for this supernova.
BLOCK: And it'll just look really bright? You would spot it right away?
NUGENT: You see the fuzzy patch in the Pinwheel Galaxy and this is the brightest thing there, so it's very, very easy to see.
BLOCK: Well, Peter Nugent, thanks for talking to us about your supernova.
NUGENT: Thank you very much for having me on.
BLOCK: That's Peter Nugent of the Lawrence Berkeley National Laboratory talking about the closest and brightest supernova to be found in decades. It's called PTF 11kly.
NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.