See a Supernova From Your Backyard

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See a Supernova From Your Backyard

Posted by samzenpus on Monday September 5, 2011 @05:00AM from the no-sunglasses-required dept.

hasanabbas1987 writes "Want to catch a glimpse of the closest supernova astronomers have discovered in the last 25 years? All you need to do is get yourself a small telescope or a pair of binoculars (some DSLRs would do just fine as well). Astronomers think that they may have found the supernova within hours of its initial explosion on August 24. Generally, supernovas are around 1 billion light years away but this one is only 21 million light years away. The supernova is in the Pinwheel Galaxy and you can see it within the Big Dipper."

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Discovered within hours of its explosion? by freaktheclown · 2011-09-05 05:07 · Score: 4, Informative

I'm pretty sure it exploded about 21 million years ago.

If a supernova were close enough to be seen within hours of its explosion, we probably wouldn't be here.
1. Re:Discovered within hours of its explosion? by freaktheclown · 2011-09-05 05:22 · Score: 4, Informative
  
  No the summary is not correct. It did not happen "hours ago" from any reference frame. Other articles written about this got it right; this one did not.
2. Re:Discovered within hours of its explosion? by Iskender · 2011-09-05 05:41 · Score: 2
  
  I suspect that a lot of the time the people pointing it out do so because they have nothing else to contribute to the discussion.
  I'm guessing it's a form of disinterest really - someone sees news about an exceptional supernova and would rather discuss a sentence in a Slashdot summary.
  Some other poster already posted a very constructive post though, I suggest we read that instead: http://science.slashdot.org/comments.pl?sid=2413680&cid=37309370 .
3. Re:Discovered within hours of its explosion? by exploder · 2011-09-05 05:49 · Score: 2
  
  There's not some cosmic clock that marks a simultaneous "now" for every point in the universe, such that the light from that supernova actually traveled for 21 million years to reach us. Simultaneity doesn't exist, independent of reference frame. In our reference frame, the supernova exploding and the light reaching us are simultaneous events. If you don't believe it, pick up a physics book--even a very watered-down pop physics book from Barnes & Noble will set you straight on this issue.
  
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4. Re:Discovered within hours of its explosion? by gmueckl · 2011-09-05 06:11 · Score: 5, Informative
  
  Yet, no time has passed for the traveling light. Or more precisely: if an observer had followed the light emitted from the supernova at almost the speed of light, very little time would have passed in his frame of reference. So what we take as 21 million years would have been nearly instantaneous for our traveling observer. Simultaneity is a weird thing when time is relative.
  
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5. Re:Discovered within hours of its explosion? by interkin3tic · 2011-09-05 06:12 · Score: 4, Funny
  
  Important lesson here: there is no "+1 pedantic" mod. On slashdot or in real life, which is why no one was too interested in making out with you new year's eve 1999 when you were telling everyone that the millennium wouldn't start until the next year.
6. Re:Discovered within hours of its explosion? by Missing.Matter · 2011-09-05 06:17 · Score: 3, Insightful
  
  Because that's what nerds do (and consequently why everyone hates them). They're infuriatingly pedantic, and love to correct people even on the smallest details because it makes them seem smarter (and therefore better).
7. Re:Discovered within hours of its explosion? by fyngyrz · 2011-09-05 06:33 · Score: 4, Insightful
  
  Because that's what nerds do (and consequently why everyone hates them). They're infuriatingly pedantic, and love to correct people even on the smallest details because it makes them seem smarter (and therefore better).
  More accurately presented / corrected is better, and the reason the people you call "nerds" infuriate others is because the lazy and low-functioning hate being reminded the things they believe are imprecise because they don't take the time (or have the ability) to think things out to a more precise conclusion.
  It is not anyone's job to dumb things down (or leave them down, when presented that way) so you'll be comfortable. If the status quo is to be moved, up is clearly the ethical and moral way to move it. If it is not to be moved, you'll need a better reason than "I'm uncomfortable with statements that are more accurate than mine."
  "Getting things right" is a much more laudable human goal than "keeping things approximate."
  Further, in this particular venue, the audience is generally a good deal smarter than, say, on Gawker. If you present in a clumsy or inaccurate manner here, it's really kind of silly to expect it to go unremarked.
  
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8. Re:Discovered within hours of its explosion? by rubycodez · 2011-09-05 06:36 · Score: 2
  
  Except you pseudo-relativity experts don't understand we can establish our reference frame as a standard, and that the exploding star is essentially in our reference frame, as it is not in relativistic motion in relation to us, nor is it or we in huge potential well in relation to each other. It's just a real-time signal propagation lag we experience, no different than sound of firecracker two city blocks away taking a second to reach you.
9. Re:Discovered within hours of its explosion? by Missing.Matter · 2011-09-05 07:00 · Score: 2, Interesting
  
  Right, exactly what I was talking about. Sanctimonious, enlarged ego, inflated sense of self importance. This post is a good example why the people I call "nerds" infuriate me and most others. You really believe you're better and smarter than most people don't you?
  
  Further, in this particular venue, the audience is generally a good deal smarter than, say, on Gawker.
  In this particular venue it's especially annoying because we all know about relativity and it's entirely tangent to the discussion.
10. Re:Discovered within hours of its explosion? by Cyberax · 2011-09-05 08:18 · Score: 3, Informative
  
  It IS different. With a firecracker we have a flash which reaches us 'instantaneously' and then a sound which takes a few moments to reach us. Moreover, different observers with clocks synchronized to a same source would see the flash at the same time (we're ignoring relativity) so they can agree on a universal frame of reference (Earth + UTC time).
  With light it's different. We have NO other faster channel. Imagine that you have no way of knowing that firecracker has exploded except by listening to a sonic boom. And you have no faster way to communicate except by shouting.
11. Re:Discovered within hours of its explosion? by superdave80 · 2011-09-05 09:15 · Score: 2
  
  Let's do a simple example to show you why you are completely wrong.
  Let's say your grandma dies right in front of me at 12:00 noon. I call you, and leave a message saying what happened. You don't check that message until 6:00 p.m. Are you really going to try and convince people that grandma died at 6:00 p.m.? Of course not.
12. Re:Discovered within hours of its explosion? by Raenex · 2011-09-05 10:34 · Score: 3, Informative
  
  It did not happen "hours ago" from any reference frame.
  Is that really true? Somebody mentioned elsewhere in this thread that:
  "Yet, no time has passed for the traveling light. Or more precisely: if an observer had followed the light emitted from the supernova at almost the speed of light, very little time would have passed in his frame of reference. So what we take as 21 million years would have been nearly instantaneous for our traveling observer."
  It seems that you can define a reference frame arbitrarily close to the speed of light at an arbitrary starting position and get the desired duration.
13. Re:Discovered within hours of its explosion? by gstrickler · 2011-09-05 11:08 · Score: 2
  
  This is correct. From the Earth's reference frame, this supernova just occurred, and it occurred 21M LY away. As I demonstrate with an example below, it is misleading and meaningless to talk about how long ago it occurred, or in which order things occurred using any other frame of reference.
  Suppose a supernova 1000LY away had two stars near enough that the supernova had an effect on them, and one of those stars (star B) was 5 LY from the supernova and one (star C) was 15 yr from the supernova. However, star C is 990 LY from earth, while star B is 1005 LY from earth. The high energy rays from the supernova will have an effect on star C 15 years after the supernova, and we'll observe that effect 990 years afterward for a total 1005 years after the supernova. Star B will be effected 5 yrs after the supernova, and we'll observe it 1005 years after that, or 1010 years after the supernova. So, 1010 years after the supernova, we will have seen all three events reach earth, but not in the order in which they occurred relative to the supernova. We observe the effect on star C 5 years before we observe the effect on star B, even though star B was 10 LY closer to the supernova and "happened first" or "longer ago".
  Now suppose (purely hypothetically, since we don't know that it's even possible) that stars B & C both emit deadly gamma ray bursts directed at earth as a result of the supernova. The burst from star C would reach us 5 years after we observe the supernova, and 5 years before we even observe the effect on star B. We would be dead and never see the effect on star B. It doesn't matter that B also emitted a deadly burst, or that "it happened first". What matters is the order in which they effect the destination, and as this example shows, that doesn't depend upon what order they occurred in from another reference frame (e.g. the frame of the supernova), or "how long ago" they happened. The effect on star B clearly happened "10 years before" star C, but what had an effect on earth first was star C, therefore making the effect on star B irrelevant to earth's frame of reference. While it's accurate that from earth's reference 10 yrs after we observe the supernova that the effects on star B happened 1005 years ago while star C was 995 yrs ago, it's also misleading and meaningless because the "more recent" event is the one that first caused a problem on earth. Causality is only relevant at the destination frame of reference, and everything occurs when it is observed, not "xx years ago".
  The physical universe is called space-time for a reason, you can not refer to space and time independently except from a single reference frame. Causality in relativistic frames (and all frames in space-time are relativistic, even if you're not moving at relativistic speeds), requires that all events be sequenced by the frame of the observer, otherwise you will encounter paradoxes of causality where some observers in different reference frames (different places in space-time) will observe two effects a and b in the opposite order. Each is correct from the frame of reference, yet it's inconsistent to say that a occurred before b, or that b occurred before a, and it's misleading to say that a occurred x years ago and b occurred y years ago because the effects on the observer are based upon their arrival at the observer's frame of reference, not the order in which they occurred in any other reference frame.
  
  --
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14. Re:Discovered within hours of its explosion? by Kagura · 2011-09-05 11:48 · Score: 5, Interesting
  
  TO READERS OF THIS STORY'S COMMENTS: If you want to read the real comments for this story, scroll 3/4 of the way down the page to skip that ridiculous "when is now in relativity" arguing that shows up in EVERY cosmology story on Slashdot. Seriously guys, shut up already.
15. Re:Discovered within hours of its explosion? by lennier · 2011-09-05 14:16 · Score: 2
  
  With light it's different. We have NO other faster channel.
  Are we so sure we don't? Or did we just decide that since we hadn't measured any such channel in 1905, then there isn't?
  It seems to me that Einstein arbitrarily decided to assume that there exists no faster channel than light in order to redefine the Lorentz contraction as a spacetime effect. Which was a clever hack and made the maths simple, but isn't much of an explanation because it then leaves us with not only no answer to "so what is the physical mechanism which causes space and time between events to appear to dilate as relative motion approaches C", but also makes it impossible to find an answer because it disallows asking the question - it shoves "why" under the carpet of kinematics, not dynamics. And assuming C is the maximum speed of signal propagation causes no end of trouble when you attempt to reconcile relativity with quantum mechanics.
  
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16. Re:Discovered within hours of its explosion? by gstrickler · 2011-09-05 16:52 · Score: 2
  
  You think wrong, I didn't lose or disprove my argument. Go back and re-read my entire post.
  For Earth, it happened a week ago. Only from the space-time of the supernova did it actually happen 21M years ago, and we're not in that space-time. From ANY other reference, it DIDN'T happen 21M years ago, it happened less than that, or (for distances greater than 21M LY) it hasn't even happened yet. That's why it's misleading and meaningless to say it happened 21M years ago. It happened last week, and it is/was 21M LY distant in space-time.
  We can calculate that in it's frame of reference it happened 21M years ago, but that frame of reference is meaningless to anyone/thing who wasn't in that space-time. Saying it happened 21M years ago for us requires a concept of a universal simultaneity (universal "now"), which would require that information be transmitted across space-time instantly, vastly exceeding the speed of light, which as far as we can tell, isn't possible.
  
  --
  make imaginary.friends COUNT=100 VISIBLE=false
Supernova fun! by Mr.+Underbridge · 2011-09-05 05:10 · Score: 5, Informative

Just as a warning to those trying star-hunting for the first time: finding this guy can be tricky. Best thing is to get some charts from AAVSO.org. Use 2011fe as the search. Print a 15 degree chart for finding the general area from the big dipper, then 1 degree and 2 degree charts for finding the supernova.
For now, the supernova is getting easier to find by the day - I tried last week and couldn't find it, but now it's pretty bright. However, finding the correct area can be tough because there's no obvious landmarks in the area unless your sky is dark enough to make out the face of the galaxy. And, unless you live in an exurban or rural area, it won't be. Otherwise, you'll need to rely on patterns of stars at the 1 degree scale. Otherwise, you can easily be looking at the supernova but not know which star it is.
There are good threads over at cloudynights.com that provide helpful images and advice. Good luck all! It's really fun to know that you're looking at something that didn't exist last month (correcting for travel time of the light, of course).
Re:ha, triangles by Dunbal · 2011-09-05 05:17 · Score: 2

Also chicks dig geometry. I get lots and lots of chicks... I think.
I think that has a lot more to do with you pouring bread-crumbs all over yourself than geometry.

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Huge Optics Needed by Iskender · 2011-09-05 05:32 · Score: 5, Informative

Another warning from another astronomy enthusiast: note that the guy in the video talks about "decent-sized" binoculars and then specifies 20x80 or 20x100.
That 100 at the end means the lenses at the front have a diameter of ten centimetres (four inches) each! So under any normal circumstances those are considered HUGE rather than decent binoculars.
My advice on how to see this supernova: ask someone into astronomy who has a telescope or huge binoculars. Doing the observing "from scratch" is probably a too tall order.
1. Re:Huge Optics Needed by Iskender · 2011-09-05 06:11 · Score: 4, Informative
  
  1.6x crop probably means you have a Canon DSLR. All I can say is that you should really explore the manual modes - with digital you can just try different shutter speeds until you get it right. The moon is illuminated by the sun so the settings that work in sunny daylight should work for photographing the moon too.
  Photographing stars often isn't a matter of magnification, but rather of light gathering. Only few stars are close/large enough to be imaged as disks, and that's with professional equipment - you'll never resolve a star into a disk yourself.
  Rather, stars are point sources. Everything comes from a single point, only the intensity and colour of that point varies. If you want to see fainter stars with a camera, you just need to expose longer. An 18-55 kit lens might very well be able to image this given the right other circumstances. The resolution of 500 mm would be more than enough in any case.
  In fact, the hardest problem would probably be to get low enough magnification - the sky moves all the time and therefore everything is blurred when you make the shutter speeds longer. This means you need large apertures more than you need long focal lengths, and pretty fast you need a tripod/mount that's capable of tracking the sky.
2. Re:Huge Optics Needed by ceoyoyo · 2011-09-05 07:55 · Score: 2
  
  The focal length of the lens and the distance of the object has very little to do with it.
  You can't get a good picture of the moon in an automatic mode because it's very bright. Go to a manual mode, dial in 1/250 s (to start) at f8 and move around until you get a picture you like.
  Focal length isn't going to make a bit of difference when you're looking at something 21 million light years away. It's a point, no matter what. The focal length of your lens will determine whether you JUST get a point of light in the frame, or whether you get some surrounding stars for context.
  No matter what, your light meter is completely useless when taking pictures of stars.
3. Re:Huge Optics Needed by GumphMaster · 2011-09-05 10:45 · Score: 2
  
  They recommended 20x80 or 25x100 binoculars. The second number is the diameter in mm of the objective (front) lens. It needs to be this big in order to collect sufficient light to make the object clearly visible to a naked eye. The first number is the magnification (crudely speaking the ratio of objective to eyepiece focal lengths). 20 is simply the common magnification in binoculars, which have fixed eyepieces, with objective lens sizes large enough to be useful.
  You'll also notice that when recommending a telescope there's no mention of focal length or magnification at all, just object lens/mirror size > 75mm. Eyepieces in telescopes can be changed to change magnification and field of view but it is the collecting area that is truly important to making the dim visible.
  Now, if only someone could move M101 about 10 or 15 degrees further south I might have a hope of seeing it.
  
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4. Re:Huge Optics Needed by gstrickler · 2011-09-05 12:55 · Score: 4, Funny
  
  All requests for moving galaxies or altering the axis of the earth must have been made (in triplicate) more than 1B years ago. Request denied.
  
  --
  make imaginary.friends COUNT=100 VISIBLE=false
Money by udachny · 2011-09-05 05:44 · Score: 2

Here is a great idea for improving the economy - stimulate more R&D, research and development, more supernovas need to be found, more telescopes must be built, put the money into this, get some engineering going. Fuck wars, lets build telescopes. Build more telescopes, build more space ships. Need more engineers for this, need more scientists, need more architects, need more of everything. Build more, spend on building, stop wars and get going.

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1. Re:Money by mikech2000 · 2011-09-05 06:03 · Score: 3, Informative
  
  Sorry but discovering interesting things about the universe offers no ROI during the next fiscal quarter.
2. Re:Money by dotancohen · 2011-09-05 06:14 · Score: 2
  
  Here is a great idea for improving the economy - stimulate more R&D, research and development, more supernovas need to be found, more telescopes must be built, put the money into this, get some engineering going. Fuck wars, lets build telescopes. Build more telescopes, build more space ships. Need more engineers for this, need more scientists, need more architects, need more of everything. Build more, spend on building, stop wars and get going.
  Go check how many space exploration lobbyists exist in Washington then check how many petroleum and military-tech lobbyists exist in Washington. Now try to rephrase your suggestion in terms of oil usage and military technology.
  
  --
  It is dangerous to be right when the government is wrong.
Re:Convenient by Noughmad · 2011-09-05 05:46 · Score: 2

Depends, is there a tinfoil commercial too?

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It's actually naked eye visible? by NotSoHeavyD3 · 2011-09-05 06:08 · Score: 2

Really? I mean I know the Andromeda galaxy is normally the furthest naked eye visible object and that's 2 million LY away. (This thing is 10X further and is still naked eye visible? That's amazing.)

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it's in our reference frame by rubycodez · 2011-09-05 06:32 · Score: 2

The star that exploded is not moving at relativistic velocities in relation to us, and the non-inertial part of our and its reference frames are tiny too. It exploded 21 million years ago in our reference frame.
Re:How Long Do They Last? by mojo-raisin · 2011-09-05 09:23 · Score: 4, Informative

I don't know how long it lasts, but its daily intensity is being plotted here. From what little I've read, it can be expected to increase like this for ~14 days from the initial explosion
Re:How Long Do They Last? by jmichaelg · 2011-09-05 10:34 · Score: 5, Informative

This web page has a graph that shows the different light curves for type 1 and type 2 supernovae.
A Type 1 supernova reaches it's peak light output around 10-15 days of the initial explosion and then exponentially decays over a period of years. As the curve is exponential, a good chunk of the luminosity is lost within a couple of months and then the loss rate tapers off somewhat.
A type 2 supernova reaches its peak output in a few days decays, plateaus for a few months and then begins decaying again over a span of years.
The mechanism behind a type 1 is fairly well understood but the variation in modeled and observed luminosity is greater than 2%. A paper a few years back suggested that the variation might be evidence of dark matter but subsequent modeling has shown that the 2% variation can be accounted for by where the observer happens to be relative to the explosion as the explosions aren't symmetric.
Re:I'm @south. by quenda · 2011-09-05 15:13 · Score: 2

I'm in the southern hemisphere, you insensitive clod!
That's OK. We had front-row seats for the 1987 supernova, a mere 168,000 light-years away, and visible to the naked eye.
The previous one brighter was in 1604.
http://en.wikipedia.org/wiki/SN_1987A