Posted on 07/28/2016 7:54:07 AM PDT by LibWhacker
For most of 2016, astronomers have been viewing a ball of hot gas billions of light years away that is radiating the energy of hundreds of billions of suns. At its heart is an object a little larger than 10 miles across. And astronomers are not entirely sure what it is. If, as they suspect, the gas ball is the result of a supernova, then it’s the most powerful supernova ever seen.
Most astronomers today believe that one of the plausible reasons we have yet to detect intelligent life in the universe is due to the deadly effects of local supernova explosions within 100 light years that wipe out all life in a given region of a galaxy. While there is, on average, only one supernova per galaxy per century, there is something on the order of 100 billion galaxies in the observable Universe. Taking 10 billion years for the age of the Universe (it's actually 13.7 billion, but stars didn't form for the first few hundred million), Dr. Richard Mushotzky of the NASA Goddard Space Flight Center, derived a figure of 1 billion supernovae per year, or 30 supernovae per second in the observable Universe! In June of 2015, this flaring spot of light was found by the All Sky Automated Survey for Supernovae (ASASSN) run by Ohio State astronomers and labelled ASASSN-15lh. Located about three billion light years distant, the source appears tremendously bright for anything so far away: roughly 200 times brighter than an average supernova, and temporarily 20 times brighter than all of the stars in our Milky Way Galaxy combined. The above-featured artist's illustration depicts a hypothetical night sky of a planet located across the host galaxy from the outburst.
“If you walked outside and saw a person who was six feet tall, and then someone who was six thousand feet tall, you would notice,” says team member Todd Thompson of Ohio State University. “You begin to question whether this is even a person.”
In the January 14, 2016 issue of the journal Science, the Ohio State team report that the object at the center could be a very rare type of star called a magnetar—but one so powerful that it pushes the energy limits allowed by physics.
Even in a discipline that regularly uses gigantic numbers to express size or distance, the case of this small but powerful mystery object in the center of the gas ball is so extreme that the team’s co-principal investigator, Krzysztof Stanek of The Ohio State University, turned to the movie This is Spinal Tap to find a way to describe it.
“If it really is a magnetar, it’s as if nature took everything we know about magnetars and turned it up to 11,” Stanek said. (For those not familiar with the comedy, the statement basically translates to “11 on a scale of 1 to 10.”)
The gas ball surrounding the object can’t be seen with the naked eye, because it’s 3.8 billion light years away. But it was spotted by the All Sky Automated Survey for Supernovae (ASAS-SN, pronounced “assassin”) collaboration. Led by Ohio State, the project uses a cadre of small telescopes around the world to detect bright objects in our local universe.
Though ASAS-SN has discovered some 250 supernovae since the collaboration began in 2014, the explosion that powered ASASSN-15lh stands out for its sheer magnitude. It is 200 times more powerful than the average supernova, 570 billion times brighter than our sun, and 20 times brighter than all the stars in our Milky Way Galaxy combined.
“We have to ask, how is that even possible?” said Stanek, professor of astronomy at Ohio State. “It takes a lot of energy to shine that bright, and that energy has to come from somewhere.”
“The honest answer is at this point that we do not know what could be the power source for ASASSN-15lh,” said Subo Dong, lead author of the Science paper and a Youth Qianren Research Professor of astronomy at the Kavli Institute for Astronomy and Astrophysics at Peking University.
He added that the discovery “may lead to new thinking and new observations of the whole class of superluminous supernova.” Todd Thompson, professor of astronomy at Ohio State, offered one possible explanation. The supernova could have spawned an extremely rare type of star called a millisecond magnetar, a rapidly spinning and very dense star with a very strong magnetic field.
To shine so bright, this particular magnetar would also have to spin at least 1,000 times a second, and convert all that rotational energy to light with nearly 100 percent efficiency, Thompson explained. It would be the most extreme example of a magnetar that scientists believe to be physically possible.
“Given those constraints,” he said, “will we ever see anything more luminous than this? If it truly is a magnetar, then the answer is basically no.”
The Hubble Space Telescope will help settle the question later this year, in part because it will allow astronomers to see the host galaxy surrounding the object. If the team finds that the object lies in the very center of a large galaxy, then perhaps it’s not a magnetar at all, and the gas around it is not evidence of a supernova, but instead some unusual nuclear activity around a supermassive black hole.
If so, then its bright light could herald a completely new kind of event, said study co-author Christopher Kochanek, professor of astronomy at Ohio State and the Ohio Eminent Scholar in Observational Cosmology. It would be something never before seen in the center of a galaxy.
If the aliens around the star say Betelgeuse three times in a row it will explode.......
Right. But the gamma will show up at the same time as the visible.
I’m not sure what you mean by “looking through it.” They don’t have to be able to see through it to measure how much radiation is being given off.
“The simple biochemistry of the notion that life is inevitable is absurd.”
Indeed, I agree.
“We haven’t even found a single planet anything like Earth.”
It’s worse than that. We haven’t even found another stellar system that resembles our own, which has effectively thrown their “nebular hypothesis” for planetary evolution into the trash bin.
“We are in the exact center and the exact oldest part of the universe.”
Correct, although most scientists refuse to acknowledge this and cling to the “cosmological principle”, an assumption that contradicts the evidence.
“I don’t mean that’s because it took light 3.6 billion years to get here. I mean that as an effect of temporal distortion of high-speed travel, there’s been less time for stuff to happen.”
Interesting. I hadn’t considered that myself, but you may be right. The only thing I’m wondering is, does temporal distortion kick in if the motion is due to the expansion of space itself? I’m not sure one way or the other, I have never really thought about it...
“Years ago, I calculated the Drake equation and estimated less than 10^1 (in other words, less than ten) worlds with intelligent life in the universe. I had badly underestimated the number of planets in a typical galaxy, but I also badly overestimated the likely habitability of life on a given planet.”
Seems like an optimistic estimate to me even so. If we didn’t know there was life on at least one planet, I would say the probability was effectively zero. Since there is life on at least one planet, then either it’s due to some extraordinary circumstance (like divine intervention), or we hit the biggest lottery drawing ever held.
They are not detecting the size directly, it’s based on assumptions about the type of object it is and calculations about how the gravitational forces and nuclear forces of such an object would interact to determine its geometry.
Basically, if they can figure out how much mass it has and what type of star it is, they can guestimate the diameter easily.
Well, the size is obviously calculated from observation data. When I said the size of the source doesn’t matter, I was thinking along the lines of seeing a large bonfire from 10 miles away vs. seeing the light emitted from a tiny LED. You see the light, not the object.
Well, damn. You mean I can’t finish “Longmire” season four?
Well, a supernova throws off a lot of mass, but gravitational waves require both mass and acceleration; it’s not enough if there is just a shift of mass. In a supernova, the mass ejected would be decelerating, unless there was some other nearby gravitational source to accelerate it, so I don’t think it could produce gravitational waves.
We’re reasoning with averages here. Ever take a statistics course?
Of course it matters how often supernovae occur. If only one occurs every ten billion years, that is not going to be enough to prevent advanced forms of life from arising somewhere in a galaxy. But if a million supernovae explode every hundred million years, that could be enough to prevent vast regions of a galaxy from ever developing multicellular life forms.
Some regions may get lucky and escape, as we may have, but most won’t. That’s the reasoning.
If they happened (emitted) at the same time that would be true, but they don’t.
Because the sequence of nuclear reactions gamma rays happen first and visible light is next.
Unfortunately for us if Earth is ever hit by a nearby supernova we will be dead by the wave of gamma rays before we see the blinding light.
OK ... didn’t know that about the sequencing. So we get blasted by gamma, then the cockroaches standing on our corpses see the big flash. Yay, cockroaches!
From what read if the Supernova is as close as 100 light years even the roaches won’t survive.
When the nuclear fires go out the core collapses at nearly the speed of light and can form a blackhole in less than a second. The next generation gravitational interferometers will be sensitive enough to detect these.
“But if a million supernovae explode every hundred million years, that could be enough to prevent vast regions of a galaxy from ever developing multicellular life forms.”
But again, we have prima facie evidence that doesn’t happen, or at least, has never happened in the entire history of life on earth.
You keep neglecting to address that fact, and until you do, your arguments are pretty meaningless.
Ah, I hadn’t thought about the collapse, yes, that would be an acceleration, thought the center of mass would remain the same, so I still am not sure if that would cause any gravitational waves.
I did address it. Life on Earth survived and evolved because it got lucky. Go take a probability class.
Meantime this may help you see the light... Throw a couple of dozen darts at a dart board (for the sake of argument, let’s say you’re not very good at darts and they strike the board at random). Was every point hit? Of course not.
Now imagine the dart board is the size of the Milky Way, 100,000 light years across. Instead of darts, now imagine you’re throwing supernovae at this galaxy-sized dart board. Was every point hit? Of course not. Not even if you threw one every 100 years for 4.5 billion years. Some regions of the galaxy are going to get lucky. Many won’t.
But Keith Richards would survive.
“I did address it. Life on Earth survived and evolved because it got lucky. Go take a probability class.”
That’s hand waving away the problem, not addressing it. We know that a galaxy-wide sterilization event, whether one single event, or an aggregation of multiple events, DID NOT occur over the entire history of life on earth, or we would not be here.
You didn’t propose that the aggregation of events would sterilize most of the galaxy and leave some “lucky” pockets, so you’re moving the goalposts now instead of accepting the obvious.
No one ever said a GALAXY-WIDE STERILIZATION EVENT EVER OCCURRED BUT YOU, LOL!!!
Look, I’m sorry you don’t understand this, but I have no desire or obligation to teach you what you obtusely refuse to even try to understand. The argument put forward by astronomers is a sound one and I’m not going to waste any more time trying to explain it to you.
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