Powerful Supernova May Be Related To Death Spasms of First Stars

necro81 writes "The New York Times is reporting on a discovery from a team of UC Berkley researchers, who may have discovered the brightest stellar explosion ever observed. Observations of the cataclysmic explosion of a 100- to 200-solar-mass star began last September, based on data from the Chandra X-ray Observatory. The researchers believe that the explosion is similar to the death spasms of the first stars in the universe. The super-massive star's collapse is believed to have been so energetic as to create unstable electron-positron pairs that tore the star apart before it could collapse into a black hole — seeding the universe with heavier elements."

Comments

Re:Time-lapse video?

[ls -la]

As far as I can tell from the articles, most of the observation was through means other than the optical spectrum pictures you're looking for (e.g. x-ray and IR pictures, spectroscopy, etc.). In fact, this supernova was so far away (240 million light years) that I'm not sure they could see it through optical telescopes. Most of a supernova's radiation (especially in something this violent) is emitted in the gamma ray range.

Here's the NASA page.

[u-bend]

Here's the NASA article about it.

Re:Eta Carinae

[Jugalator]

It's not too bad unless we'd be unlucky and have a gamma radiation burst from it heading towards us.
From here:

The potential danger comes from the fact that explosions of massive stars generally emit jets of intense gamma radiation, among the most powerful and harmful forces in the universe. If Eta Carinae did explode and a jet was pointed in the general direction of the solar system, Livio said, Earth could be endangered. But because the gamma-ray jets tend to be relatively narrow, like the beam of a lighthouse, the odds are that the jet would miss Earth.

So it's not too bad, it would probably just miss us.

:-/

Re:we should we believe the astrophysicists now?

[Red Flayer]

Just goes to show you the arrogance of physicists- they claim answers and grandiose Standard Theories, but are frequently revising them because they mis things like accelerating expansion and 150SM supernova.

Right. So we should not put blind faith in any theory, because it's open to being falsified. That's basic scientific method stuff.

Isn't this what academic research is (in theory) all about? The search for better understanding, enabling us to revise our theories of how the universe (or some small subset of it) works?

Find the simplest theory that fits all the observations. New data may mean you need a new theory, or that you need to revise your current theory. I don't understand the problem you have, unless it's just with the arrogance of some theorists who claim to have found the answer to Life, the Universe, and Everything. I say, let them be arrogant -- when they are disproved, they'll fall harder for it.

Re:Actually, it's T E X A S

[MontyApollo]

From the article:

The discovery was made by Robert Quimby, a University of Texas graduate student, who was using a small robotic telescope at McDonald Observatory near Fort Davis, Tex., to troll for supernovas

Re:Oddity

[ls -la]

I guess they should say "might see if it went supernova soon."

We know information cannot travel faster than the speed of light (or if you prefer, cannot reach outside the light-cone of the event). So if an event "happens" 7500 light years away, did it really happen before the light reaches us? In some sense, an event has not happened until we are inside its light-cone.
Perhaps it "happens" when its light-cone intersects ours? The question with this interpretation is, where does our light-cone start?

Time is relative, and over distances of at least the order of a light second (186,000+ miles), it is difficult to think about correctly.

Re:Eta Carinae

[vrmlguy]

First, Eta Carinae is not visible to anyone north of 27 N, so in the US only people in or south of Miami will see it. In Africa, you basically have to be in a country that doesn't touch the Mediterranean Sea; while in Asia every country touching the Indian Ocean will see it, but not China or Japan. Among English-speaking countries, only Austrailia will have a great view, but the ozone layer will protect them (and the rest of the Southern Hemisphere) from direct radiation. "Scientists at NASA and Kansas University have determined that the supernova would need to be within 26 light years from Earth to significantly damage the ozone layer and allow cancer-causing ultraviolet radiation to saturate the Earth's surface. An encounter with a supernova that close only happens at a rate of about once in 670 million years(...) The new calculations are based largely on advances in atmospheric modeling, analysis of gamma rays produced by a supernova in 1987 called SN1987a, and a better understanding of galactic supernova locations and rates. A supernova is an explosion of a star at least twice as massive as our Sun." Since Eta Carinae is 300 times that distance, its blast wound need to be 90,000 times as energetic to be dangerous. A hypernova is about 100 times more powerful than a supernova, so there's plenty of margin of safety there.

Re:Oddity

[Orange Crush]

There is no such thing as synchronicity in this universe. Cause travels at the speed of light (or slower), gravity and relative velocity alter time and quantum states are ambiguous until observed. That star has a high probability of already having gone supernova, but this is meaningless in our frame of reference until the event is observable.

Re:Time-lapse video?

[$RANDOMLUSER]

Indeed. The best images are from the Chandra X-ray observatory. They have some animations here.

Re:Time-lapse video?

[p_trekkie]

Most of a supernova's radiation (especially in something this violent) is emitted in the gamma ray range.

Actually, most of the radiation comes out as neutrinos. Only 1% comes out in forms we can detect at all...

Re:Time-lapse video?

[imsabbel]

Also:
"
The core implodes at velocities reaching 70,000 km/s (0.23c),[40] resulting in a rapid increase in temperature and density. Through photodissociation, gamma rays decompose the iron into helium nuclei and free neutrons. The conditions also cause electrons and protons to merge through inverse beta decay, producing neutrons and electron neutrinos. About 1046 joules of gravitational energy are converted into a ten-second burst of neutrinos.[41] These carry away energy from the core and accelerate the collapse, while some neutrinos are absorbed by the star's outer layers and begin the supernova explosion.[42]

The inner core eventually reaches a density comparable to that of an atomic nucleus, where the collapse is halted. The infalling matter then rebounds, producing a shock wave that propagates outward. This expanding shock can stall in the outer core as energy is lost through the dissociation of heavy elements. However, through a process that is not clearly understood, the shock reabsorbs 1044 Joules[a] (1 foe) of energy, producing an explosion.[43]"

You might have stumbled upon this part of the article while getting to the part you quoted. 10^44 joule ->explosion, 10^46 joule -> neutrino burst.
->only 1% is visible.