New Supernova Seen In Nearby Galaxy M82 125
The Bad Astronomer writes "A new and potentially bright supernova was just discovered in the nearby galaxy M82. This is a Type Ia supernova, the catastrophic explosion of a white dwarf. It appears to be on the rise, and may have been caught as much as two weeks before peak brightness. It's currently already brighter than magnitude 12, and may get to mag 8, easy to see in small telescopes. The galaxy is less than 12 million light years away, so this may become one of the best-studied supernovae in recent times. Type Ia supernovae are used to measure dark energy, so seeing one nearby is a huge boon to astronomy."
I hope no one got hurt (Score:2)
Re:I hope no one got hurt (Score:4, Funny)
Just sayin'.....
It was a long time ago in a galaxy far, far away.
And yes, many Bothans died to bring us this information.
It was a Trap!
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Only 12 Million years ago, and the Galaxy is relatively close.
I wonder how many star systems got sterilized by the blast.
Re:I hope no one got hurt (Score:4, Insightful)
White dwarf? The inhabitants had long since resettled, if they knew about themselves.
The sad nature of the universe is that untold numbers of unique lifeforms have been summarily extinguished by the the deaths of their stars for billions of years.
Re:I hope no one got hurt (Score:5, Interesting)
Supernovas can affect the biospheres of planets within eight parsecs [wikipedia.org]
Still, that's nothing compared to the hypothetical death tolls in active galaxies.
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Sirius is still nice and white, we've no problems there.
It's Arcturus you should worry about; it's already in its red giant phase.
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But Arcturus is 36.7 light years distant--11.24 parsecs. We're safe. As long as the supernova occurs more than 8 parsecs away. the ozone layer won't be catastrophically damaged.
Obligatory XKCD: Another way to die in a supernova [xkcd.com]
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Supernovas can affect the biospheres of planets within eight parsecs
Oblig: well that's farther than the time to do the Kessel Run.
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no, zero lifeforms extinquished by the death of their own star, for stars kill their habitable planets long before dying.
getting extinguised by a nearby star of another system is possible
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no, zero lifeforms extinquished by the death of their own star, for stars kill their habitable planets long before dying.
The supernova is just the final event in the very long process of a star's death.
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Actually, the habitable zone just moves outward, potentially making formerly uninhabitable outer planets (and moons) habitable. I don't see why life couldn't develop on those planets given enough time, which would be possible with smaller stars that die a slow death.
Re:It was on the rise... (Score:4, Interesting)
Re:It was on the rise... (Score:5, Informative)
Since no information can travel faster than light, for all intents and purposes and discussions of causality it is happening right now. Since we are just entering its light cone, anything outside of it is inaccessible to us - and always will be.
Well, if you argue that, you have to give up concept of distance, or concept of speed of light. From our frame of reference, light traveled certain distance at certain speed, and simple calculation will tell how long time it took.
Or to put it another way, when you receive reflection of light you sent to a mirror, neither sending nor reflecting happened when you received the reflection back. It is in fact possible to determine distance of mirror by knowing how long ago sending and reflecting happened.
Re:It was on the rise... (Score:4, Informative)
Over such distances the expansion of space is totally insignificant -- that's a large scale effect and is *only* active on large scales. Local structures are totally disconnected from it. (If the language doesn't sound intimidating, the expansion is a feature of the Robertson-Walker metric, which is assumed to be valid on very large scales. It is not a feature of Schwarzschild, Kerr, Lemaitre-Tolman-Bondi, Szekeres or other metrics that describe smaller structure, although it's true that you can find, say, an LTB that also has a cosmological constant. Since local structure will be described by something close to a Szekeres, it is not influenced by the "universal" expansion.) It's a bit like the universe is that old expanding rubber sheet, and local structures are pebbles rolling around on it. The pebbles aren't growing, even though the space between them is.
Extra points for anyone spotting an enormous logical flaw in this picture that is at the heart of one of cosmology's biggest (and unsolved) fundamental issues.
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"Is only *significant* on large scales, and in particular in the weak-field limit, no?"
Actually no, in the hard interpretation of what I'm saying -- that the acceleration predicted in cosmology is a result of assuming a negative pressure in a Robertson-Walker metric... but the universe is composed of a conglomeration of untold billions of different metrics -- there is no weak-field limit. In the softer interpretation where structure forms and "disconnects" in some way or another from the universal expansion
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"Floundering around continuing to wonder what mechanisms generate the metric is pretty much the job description of a physical cosmologist, isn't it ?"
Certainly one part of the job description, yes :) Most of them would disagree with almost everything I say about how to approach it, of course, which is what makes the whole thing great. In about ten years when all the data is in we'll be drowning in too much of it and I more or less expect more funding in cosmology to be channelled into more genuine theorists
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Definitely the bottom-up approach. It's almost intractible, but it's still easier than attempting to decompose a metric into constituents. A major issue is that general relativity is not linear, so if you've got two Schwarzschild metrics (which describe a spherical mass alone in the universe, edging towards flat spacetime inifinitely far from the mass) you can't simply add them together and get a new metric describing two spherical masses. In the weak-field regimes this will work OK but it's still only an a
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"Or do you mean something as strong as being unable to predict the evolution of some arbitrary lower-dimensional hypersurface matching a real observation?"
This may be the case. If nothing else, in cosmology we know we are not in a globally hyperbolic spacetime: the universe is riddled with geodesic crossing. That in itself makes a 3+1 split and any evolution based on it problematic. Cosmology is inherently built on a 3+1 split of some form, whether that's with respect to an observer comoving with the CMB or
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Actually, if you want to be accurate: no, it is not a simple calculation, due to the metric expansion of space and all...
I don't want to be accurate to that degree. There's no point. The expansion at 12 million light year scale is who knows how many orders of magnitude less than the accuracy of our best measurements of the distance.
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Well, if you argue that, you have to give up concept of distance, or concept of speed of light.
No, you just need to give up the concept of simultaneity: the idea that two events at different places can happen at the same time. And that's what you actually have to do to make relativity work. It sounds ridiculous ("counterintuitive" is the usual term), but it's the way the universe works [wikipedia.org].
It is in fact possible to determine distance of mirror by knowing how long ago sending and reflecting happened.
The time taken for the light to reach the mirror and come back, and hence the measured distance to the mirror, will actually depend on your reference frame (i.e. how fast you're moving when you measure it). Another
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You are needlesly introducing multiple reference frames. Here there's just on that is relevant: ours. If event happened 12 million light years away, it also by definition of speed of light happened 12 million years ago, when we see the light. When observing photons in vacuum, distance and time are same thing. "Now" would mean "here", and I don't feel the heat, so inverse square law must be in effect, which implies distance, which implies time.
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no, that ship can never outrun any of the light showing its history, so we can watch it launch and speed up and arrive.
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it doesn't matter that it's a ship, you could ask the same question about a baseball thrown at you. there is no "reconcile" point but a continuum, the object is seen to leave one place, travels and to arrive.
Re:It was on the rise... (Score:5, Insightful)
> I'm always stressing to people at our star parties the light you see is history.
I'm surprised they still invite you. They probably already know.
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> I'm always stressing to people at our star parties the light you see is history.
I'm surprised they still invite you. They probably already know.
I'm usually the one with the telescope, making peoples minds boggle. Explaining the speed of light and vast distances I usually have a rapt audience who aren't given to thinking about these things. Nothing quite like a Star Party to answer the questions the people themselves are asking. We don't have the great pictures of Hubble or Spitzer, but we have people who aren't watching TV, but are actually seeing things through the eyepiece and getting some of the science explained first hand.
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I can't see through a monocular eye piece, you insensitive clod. ;-)
Actually, that part is true ... when I try to look through a telescope eye-piece all I see is a blob, but strangely, I can see through my DSLR (which seems to have a larger eyepiece than most telescopes do). But I've literally never seen anything through a telescope, which kinda bums me out, because I'd like to.
I strongly suspect that m
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I can't see through a monocular eye piece, you insensitive clod. ;-)
Actually, that part is true ... when I try to look through a telescope eye-piece all I see is a blob, but strangely, I can see through my DSLR (which seems to have a larger eyepiece than most telescopes do). But I've literally never seen anything through a telescope, which kinda bums me out, because I'd like to.
I strongly suspect that means I'm either an idiot, or looking through the wrong end of the telescope. Of course, the latter could be a symptom of the former.
Years ago I invested in a motorized Reverse Crayford Focuser (from Jimsmobile) for my telescope. It's been the single best investment - no more motion on distant, high magnification objects from contact with the scope and I can hand the little control unit to anyone to adjust the focus best for their vision. Can't imagine doing these big star parties without one.
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Optical devices, such as cameras with optical viewfinders, telescopes and binoculars are designed to to be used with the eye a certain distance away from the eyepiece's lens. This distance is known as "eyepoint", and pesons wearing eyeglasses often have difficulty using "low eyepoint" devices.
Re:It was on the rise... (Score:4, Insightful)
Technically, everything you ever perceive is in the past. More often than not, two simultaneous perceptions of the same thing are not even the same past.
How brains manage to correct for both the perception latencies and the action latency, so that we can interact with our environment, is pretty amazing.
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Technically, everything you ever perceive is in the past. More often than not, two simultaneous perceptions of the same thing are not even the same past.
How brains manage to correct for both the perception latencies and the action latency, so that we can interact with our environment, is pretty amazing.
I try to convey to people that we are effectively, for the sake of explanation, a fixed point in the middle of an aquarium - with little floaty bits all around us in the water, moving at their own velocity on their own course. The light we see took some time to reach us and that floaty bit we think is there is since moved. If we got in a high speed star ship and traced the route back to it we'd find that route likely contains curves and even moves a bit as the gravity of other bodies have diverted it ever
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This is just patently abs.. ALL GLORY TO THE GREAT HYPNOGALAXY!
(and a few words for the all-caps filter)
Re:It was on the rise... (Score:5, Informative)
Except, in our frame of reference, it's happening now, even though it happened then.
Which means in the future, we will would have seen this from before, but we won't have yet known if more stuff which will would have happened in the past will be happening in the present as the future unfolds.
So it is simultaneously not happening now, and happening now -- it isn't really happening now there, but here it is happening now, except it already happened there, and technically it has already happened here, but we're only now becoming aware of it now, but in the future, both will have happened in the past.
Which is why we stick with tenses which make sense to our poor little brains. it's just too damned hard to conjugate the verbs. ;-)
So, from what I've been able to tell -- we discuss it in the present tense, and then occasionally remind ourselves that we're seeing something which happened a long time ago. But then we try not to mix up the two, because it hurts more than an ice-cream headache.
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Thank you, Dr. Streetmentioner.
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Never, as soon as it's then, then it will be now (but then), but then will refer to a different then than now, and a different now than now because it's then.
Then the now that will be used then is what we now refer to as then. Then we'll have another then from the now that is then, and the then then becomes now. The now we use right now will no longer apply, but the then we use now could still apply then if then was further out than then as of now and then.
And it's turtles all the wa
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When will then be now? [youtube.com]
Soon.
Re: It was on the rise... (Score:2)
Goon show what time is it
http://m.youtube.com/watch?v=-... [youtube.com]
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Time doesn't travel - that's as meaningless as saying "does left travel at the speed of light" or "does up move more slowly than diagonal?" It's just another dimension, and one the choice of which general relativity makes extremely arbitrary.
Re:It was on the rise... (Score:4, Informative)
Except, in our frame of reference, it's happening now, even though it happened then.
Nope. In our frame of reference, it most definitely happened then. The light is reaching us now. It's too late to emit a beam of light of our own to meet the supernova light halfway, which it wouldn't be if it was happening now.
The only reference frame at this point in space in which it is happening now is that of the light which is reaching us.
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Except, in our frame of reference, it's happening now, even though it happened then.
Nope. In our frame of reference, it most definitely happened then. The light is reaching us now.
Well, in common language, there really are at least two "nows". There's "now"(1), as in what may literally be happening somewhere I can't perceive at the moment. "My friend is working at his office now." What I really am saying most of the time is "Based on past information, I predict that if we measured the position and activity of my friend at time T0 -- this instant -- we would be likely to find out at some point in the future (T1) that at T0 my friend had been working at his office."
But there's als
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Well, in common language, there really are at least two "nows".
When someone starts a sentence during a discussion related to astrophysics with "In our frame of reference..." I think it's safe to assume they're talking about now(1).
from an epistemological standpoint.
Okay, now you're just making up words! ;)
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12 million years ago.
thanks for clarifying that, I mistaken from the article it was two weeks ago.
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12 million years ago.
thanks for clarifying that, I mistaken from the article it was two weeks ago.
12 million years + 2 weeks. News doesn't travel as fast as it once did.
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I might be bad at math, but 12 million years plus two weeks is still exactly 12 million years.
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Please tell me, precisely, the decimal value of Pi.
3
3.1
3.14
3.142
3.1416
3.14159
Saying "Precisely" and "Pi" is error in numeric values. 3 is no more wrong to say than 3.14159 is. Precision is relative at that point. How accurate do you need to be? a table with a circumference of 18 feet has a radius of just under 3. Saying pi is 3, radius is 3 is reasonable for getting a tablecloth, or knowing how much skirting you need or whatever else your measuring.
On the other hand, we now know the complete value of Pi to
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On the other hand, we now know the complete value of Pi to enough digits that we can encircle the entire Universe and be accurate to the NANOSECOND. How accurate is enough?
You can quit when you reach the last digit of Pi. That'll be enough. Call me when you're done.
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Just in time for the dupe.
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12 million years ago.
Well that depends on your frame of reference, doesn't it?
LOL ... (Score:3)
I love Astronomers ... sure, 12 million light years away can be construed as 'nearby' on some scales.
Obviously galaxies tend to be a little further away, but it's definitely a relative use of the term 'nearby'.
Having said that ... go science! This is pretty cool.
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I love Astronomers ... sure, 12 million light years away can be construed as 'nearby' on some scales.
Obviously galaxies tend to be a little further away, but it's definitely a relative use of the term 'nearby'.
Having said that ... go science! This is pretty cool.
I always get a kick out of the title "The Local Group", which means stars in our relative vicinity, 12 ly or so. Big distances, but if you can't handle 'relative' then it's tough sledding doing anything with astronomy.
Re:LOL ... (Score:4, Informative)
I always get a kick out of the title "The Local Group", which means stars in our relative vicinity, 12 ly or so. .
The Local Group is actually a collection of nearby galaxies, not stars. The closest member (not including the Milky Way) is 25k ly away...
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12 million light years away can be construed as 'nearby' on some scales.
I'm going to check that out. AFK, BRB.
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Obviously galaxies tend to be a little further away, but it's definitely a relative use of the term 'nearby'.
Conceptually?
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It's well within the Virgo Supercluster, but outside the local group, Happy now?
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Most of my career has been taken up in cosmology. To me, a megaparsec is the smallest smidgeon that I'll even consider looking at. (Well, until more recently when I've deigned to look at scales as small as a few thousand parsecs.) For context, a megaparsec is the size of a supercluster of galaxies, something like three or four million light years.
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Huge boon (Score:1, Offtopic)
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No boom today. Boom tomorrow.
Always boom tomorrow.
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+100 Ivanova points for you!
M81 and M82 (Score:2)
Re:M81 and M82 (Score:4, Funny)
The galaxies M81 and M82 are only about 300K ly from each other. A decent telescope can image them both at the same time.
Not if you were standing between them.
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The galaxies M81 and M82 are only about 300K ly from each other. A decent telescope can image them both at the same time.
Not if you were standing between them.
I will make sure not to do that during the next star party.
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The galaxies M81 and M82 are only about 300K ly from each other. A decent telescope can image them both at the same time.
Well, technically, the less decent the telescope is the better the chance of "imaging" both at the same time - less magnification = larger FOV. Any photo of the night sky at the right time would contain both, not that you'd actually see them.
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Actually the better telescope (Cost more) is the one with the largest apeture and the lowest focal ratio (lowest mag) because highly curved mirrors needed for lower mag are hard to produce.
I'm really not an expert in telescopes, but from what I've seen you can spend a lot of money on a telescope in almost any focal ratio. Also, strictly speaking lower focal ratio doesn't necessarily mean lower magnification, but it does mean lower magnification for a given aperture. Virtually all telescopes involve compromise from engineering feasibility to siting to cost. A moderately-priced scope with a nice wide FOV might be desirable for scouting for asteroids, while scopes placed in space don't really
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You're better off going to someplace like space.com or phys.org. More science news and better discussions than the old "that light traveled for 12 MILLION YEARS!!!!11111!!!!!" or "12 million light years is considered near by?!?!?!!!!!LOLzzz!!!! HeeHee... HERP" ramblings we have to hear anytime astronomy information is posted here.
Neutrinos? (Score:5, Informative)
THE question I am sure many will think about is how many neutrinos will be detected.
For supernova 1987a at 168'000 light years 24 neutrinos have been detected.
At 12 mega light years M82 is 71 times further, which dilutes the neutrinos by a factor ~5000.
So the answer is 0 neutrino if the detectors were the same as in 1987.
I doubt that the present detectors have improved by a factor 1000 in the meanwhile,
but I would be glad to be disproved.
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1987A was also in one of the Magellanic Clouds, which are climbing all over us. It seems unfortunately unlikely we'll get many neutrinos from this, although the improvement in technology since the 80s might mean we get roughly the same number as from 1987A. (Less than 20 detections -- 17 or so, if memory serves me, which these days it rarely does.)
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It's a type Ia supernovae, which do not produce neutrios in large numbers. So even if it were at the same distance as 1987A (a type II SNe), we still woudn't expect to detect any.
Rare to see the word nearby in astronomy articles (Score:2)
Should we get out our sunscreen?
Comment removed (Score:3)
I, for one (Score:1)
... would like to welcome our new supernova refugee overlords!
Easy to see? (Score:3)
It's currently already brighter than magnitude 12, and may get to mag 8, easy to see in small telescopes.
That's a pretty optimistic statement given the rampant state of light pollution around the world!
The naked eye limit is Mag. 3 for most of us who live near any streetlights. Magnitude 8 objects require a 6-8" telescope, preferably with tracking if you want to find the Mag. 8 galaxy.
I don't think of telescopes above 4" as "small."
I type this not to be annoying, but because a lot of people are going to waste a lot of time at night trying to see this thing when it is likely beyond their equipment (or patience) limit.
space (Score:2)
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Strictly speaking it goes to show that a white dwarf can have a life cycle. The galaxy this supernova went bang-bang in is going to happily carry on for billions upon billions of years yet.
Perk (Score:1)
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It does. I know Spaceward Ho! had events like that occasionally. Did Master of Orion 2 as well?
Re:it's not "new" (Score:4, Insightful)
The information is new to us. Take your meds.
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We're observing it some 12 million years after the fact. That hardly qualifies as "new".
Slashdot always lags behind the facts a few days, or more...
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> "The galaxy is less than 12 million light years away, ... so seeing one nearby ..."
We're talking galaxies here. Andromeda is the closest spiral galaxy to us, and that's 2.5 million light years away.
And it's HEADING STRAIGHT FOR US!!!