'Instant Cosmic Classic' Supernova Discovered

chill sends this quote from a news release by the Lawrence Berkeley National Laboratory: "A supernova discovered yesterday is closer to Earth — approximately 21 million light-years away—than any other of its kind in a generation. Astronomers believe they caught the supernova within hours of its explosion, a rare feat made possible with a specialized survey telescope and state-of-the-art computational tools. 'We caught this supernova very soon after explosion. PTF 11kly is getting brighter by the minute. It’s already 20 times brighter than it was yesterday,' said Peter Nugent, the senior scientist at Berkeley Lab who first spotted the supernova. ... the supernova is still getting brighter, and might even be visible with good binoculars in ten days’ time, appearing brighter than any other supernova of its type in the last 30 years."

Comments

Re:Astounding!

[AstroMatt]

It's nearly always phrased this way. It was discovered within hours of the initial signal of the explosion reaching earth. Matt Wood

Re:Astounding!

[__aaqvdr516]

Colonel Sandurz: Try here. Stop.
Dark Helmet: What the hell am I looking at? When does this happen in the movie?
Colonel Sandurz: Now. You're looking at now, sir. Everything that happens now, is happening now.
Dark Helmet: What happened to then?
Colonel Sandurz: We passed then.
Dark Helmet: When?
Colonel Sandurz: Just now. We're at now now.
Dark Helmet: Go back to then.
Colonel Sandurz: When?
Dark Helmet: Now.
Colonel Sandurz: Now?
Dark Helmet: Now.
Colonel Sandurz: I can't.
Dark Helmet: Why?
Colonel Sandurz: We missed it.
Dark Helmet: When?
Colonel Sandurz: Just now.
Dark Helmet: When will then be now?
Colonel Sandurz: Soon.

Close, like real close

[JoshuaZ]

This is close enough that you can see it with a good amateur telescope. The supernova will brighten over time, probably hitting its brightest point sometime in the middle of September. As it brightens it might even be possible to see it with a cheap telescope or a pair of binoculars.

One thing that is important to realize is that this supernova is Type Ia, not Type II. Type II supernovae are what most people are thinking of when they think of a supernova (that is, death of a massive star). A Type Ia supernova instead occurs in a binary system where one of the stars is a white dwarf. The white dwarf slowly steals away mass from the other star until the white dwarf gets too big to be stable, around 1.4 times the mass of the sun. Then it experiences collapse in a way that is essentially similar to that of the Type II supernova.

This supernova was very close to us. One thing that could be very promising is if this left any neutrino signature above the background level. Neutrinos are very hard to detect, the major detectors are things like IceCube http://en.wikipedia.org/wiki/IceCube_Neutrino_Observatory or Super-K http://en.wikipedia.org/wiki/Super-Kamiokande which have very large containers of water or some other substance and you then carefully try to detect the very rare neutrino interactions over all the background radiation (neutrinos are very ghostly and don't interact very much. You have billions of them going through you all the time and you don't even notice). This has only happened with one supernova before SN 1987A http://en.wikipedia.org/wiki/SN_1987A which was bright enough and close enough to be seen by the naked eye. One really cool thing about this was that we actually recorded the neutrino burst for SN 1987A before the light arrived (three hours before). At this point, most people get shocked because they know that nothing travels faster than the speed of light. What happened was that in a Type II supernova neutrino burst occurs at the very beginning of the supernova process, but the light has to work its way out of the whole star. This actually allows us to potentially detect supernova before they happen, and there's now an early warning network with the major neutrino detectors so astronomers can get a heads-up if a type II is about to happen so they know where to point the telescopes. http://snews.bnl.gov/ Since the neutrino flux drops off quickly (like 1/r^2), supernovae need to be very close to us for to be able to pick out the neutrinos over all the solar neutrinos and general background junk. I don't fully understand the dynamics of Type Ia supernova (and I'm not an astronomer or an astrophysicist) but my impression is that there's also reason to believe that type Ia will produce fewer neutrinos than a Type II supernova. Between that and the distance, this supernova was probably too far away for us to detect any neutrinos.I suspect that the people who run the major detectors are probably looking over their data for the last few days very carefully to see if they can pick up any signal that the regular automated systems missed.

Re:Close, like real close

[StupendousMan]

Alas, we shouldn't expect any neutrinos to be detected from this event. I am an astronomer who studies supernovae, and the Type Ia events --- those due to a runaway thermonuclear reaction inside a white dwarf --- do _not_ produce the same sort of giant burst of neutrinos as core-collapse events.

In addition, this supernova is much, much farther away than SN 1987A. This event, in M101, is about 6400 kpc away, while SN 1987A was only about 50 kpc away. So, in very rough terms, the new SN is about 100 times farther away ... which means than the flux of particles from it will be about 100*100 = 10,000 times weaker than that from an object at the distance of SN 1987A. We only detected about 30-40 neutrinos in total from SN 1987A, so, even if this new supernova was a core-collapse event (which it isn't), we might only expect 40/10,000 = 0.004 neutrinos to be detected.

Yes, yes, today's neutrino detectors are larger than the ones operating in 1987. However, I don't think they could make up this sort of difference. And remember, a Type Ia supernova doesn't produce as many neutrinos to start with.

But this should be a good object for people to see through telescopes or (possibly) binoculars!

Re:Close, like real close

[Kentari]

At least 2 have occured but have gone unnoticed at the time: The Cas A supernova remnant is about 350 years old, discovered as a radio source in 1947 and supernova remnant G1.9+0.3 which is less than 150 years old but only discovered using radio telescopes in 1984.

Re:Astounding!

[Forty Two Tenfold]

+1 Informative.

Re:1987 Called

[alendit]

the supernova is still getting brighter, and might even be visible with good binoculars in ten days’ time, appearing brighter than any other supernova of its type in the last 30 years.

SN 1987A was a Type II supernova, this one ist Type Ia.