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Supernova 2011b Gradually Fading

Posted by timothy on from the worth-it-for-the-pictures-and-reflections dept.

An anonymous reader writes "The recent stellar explosion known as 'supernova 2011b' is gradually fading after outshining its host galaxy for over a month. The explosion first flared up in early January, and peaked at magnitude 12.9, putting it within the reach of many amateur telescopes. The host galaxy, NGC 2655, lies 64 million light years away, meaning that the star exploded while the dinosaurs still roamed the planet. My own sketches are available at gkastro.tk/."

31 of 122 comments (clear)

  1. Bam! by Suki+I · · Score: 3, Funny

    Emeril sure gets around.

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  2. Sketches? by TiggertheMad · · Score: 4, Insightful

    Pics or it didn't explode....

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  3. Here's my sketch by NEDHead · · Score: 5, Funny

                    *

  4. Dinosaurs? by name_already_taken · · Score: 4, Informative

    I thought the dinosaurs died out 65 million years ago?

    That means they were already dead for a million years, 64 million years ago.

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    1. Re:Dinosaurs? by JustOK · · Score: 2

      not enough, depending on the friend

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    2. Re:Dinosaurs? by Suki+I · · Score: 4, Funny

      We will know the real distance when the bang gets here, as long as someone remembered to count when they saw the bang.

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    3. Re:Dinosaurs? by Anonymous Coward · · Score: 2, Informative

      NO. In our frame of reference it happened ~64 million years ago and we are just now finding out about it. The only frame of reference where it occurs "now" is the frame of reference of the photons traveling at the speed of light. Relativity doesn't work that way.

    4. Re:Dinosaurs? by wierd_w · · Score: 4, Informative

      Sorry AC, Light cone is the correct terminology when discussing relativistic phenomena. It has to do with how the posibility function looks when graphed; it creates a cone shaped region. anything inside the cone is observable at some point in the lifetime of that photon generating event, anything outside that cone is not observable.

      The point that the GP was trying to drive home is that relativity outright rejects the notion of "standardized time", and also any notion of a "universal reference point" from which to observe without also suffering from relativistic effects.

      This is because time is a variable under relativity, and because all objects are in motion, and thus subject to relativistic effects. Your suggested correction of "light sphere" may not look very spherical from a specific vantage point, due to non-uniform spacial curvatures interacting with that light.

      Long story short, your correction is in fact, incorrect. Sorry.

    5. Re:Dinosaurs? by Anonymous Coward · · Score: 2, Interesting

      My thumb is the size of that car, from my frame of reference. The only way to compare them is to move both of them to the same frame of reference.

      Problem is, as I walk towards that car to compare my thumb with it, the car moves away faster than I can walk, so my thumb is getting bigger and bigger all the time.

      Sometimes we need an abstract frame of reference. It's no use saying "nothing moves faster than a photon" so we need to be limited to the speed photons can move. What we need to do is move both events to an abstract reference, possibly one in which both events are at rest with its own background microwave radiation, that is they are at rest with the "distant stars".

      Then you can say the supernova exploded 64 million years ago.

  5. Fading more newsworthy than exploding? by sosaited · · Score: 2

    Interestingly enough, the news of the supernova's explosion didn't made it to Slashdot, but it fading away was more interesting somehow. Kinda like when George W. Bush left the office I guess.

  6. Slasdot slow as usual by $0.02 · · Score: 5, Funny

    A supernova explodes. Slashdot reports 64 million years later.

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    If enithin kan gow rong it whil. (Murfey)
    1. Re:Slasdot slow as usual by SETIGuy · · Score: 4, Funny

      Don't worry, Slashdot will report it again tomorrow.

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  7. Damn it! by Lotana · · Score: 2

    If only I would of found out about the supernova back in January! Never seen one before and it is possible that there won't be another within my lifetime. At least I can still find this one in the sky before it completely fades.

    Obviously Slashdot can't be relied upon to give us up-to-date news. What sites do you use to be notified of non-mainstream events like this as they happen?

    1. Re:Damn it! by Suki+I · · Score: 5, Informative

      http://www.novaresource.org/

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    2. Re:Damn it! by jc42 · · Score: 4, Informative

      If only I would of found out about the supernova back in January! Never seen one before and it is possible that there won't be another within my lifetime.

      Don't worry. If you accept supernovas like this one, that's in a different galaxy than ours, there are plenty of them somewhere in the universe every year. It's only if you want one in our galaxy that you have to wait, since the frequency is on the order of one per century.

      There was one in the Large Magellanic Cloud back in 1987, easily visible to the naked eye (if you were in the southern hemisphere).

      Actually, it's getting to be time we had one in our galaxy. But unfortunately, they don't seem to be scheduled anywhere that we can easily read. The schedule has probably been on file at our local planning department in Alpha Centauri for 50 of our years, but we can't be bothered to make the short trip to check it out. So we'll just have to keep looking up at the night sky until something new appears there.

      --
      Those who do study history are doomed to stand helplessly by while everyone else repeats it.
    3. Re:Damn it! by robogun · · Score: 3, Informative

      It's not that bright, you need a good telescope to see it. Not that rare either, one hits 12th magnitude once or twice a year. It looks like just another very dim star in the scope. The difference between January and now isn't much at all.

      Now, if one were to pop off in our part of the galaxy it would be news. Astronomers have been waiting for one visible to the naked eye for about 400 years.

      Here's a list of current supernovae:
      http://www.rochesterastronomy.org/supernova.html

  8. rhetorical question by shadowofwind · · Score: 4, Insightful

    When an event is X light-years away, and we're just seeing it now, people speak of the event "having happened" X years ago, on the grounds that it takes X years for light to travel that distance. But how meaningful is it to think of the faraway event as being exactly concurrent with an earthly event X years ago? Light from faraway shows events from when the universe was/is in a less advanced state, so we may try to think of that as the "past". But in a way, for us, those far away events are really "now". There isn't a previous time at which we could witness them without time travel, not even in principle. Furthermore, the thought that "the event really occurred X years ago" seems to assume a universal standard of time, independent of the location and velocity of the observer, by which far apart events can be ordered. But time is not like that is it?

    1. Re:rhetorical question by Daniel+Dvorkin · · Score: 4, Informative

      No, it's not; you're absolutely right. In our frame of reference, it just happened recently -- and while you could say, "yeah, but in the star's reference frame, it happened tens of millions of years ago," it's also true that in the star's reference frame, dinosaurs on Earth are just now going extinct. IOW, it's not a very meaningful reference frame from where we're sitting.

      The "well, actually it happened X million years ago" comments that seem to accompany every /. story about some distant, recently observed astronomical event are an example of the classic nerd failing of assuming that because we're smart people who know a lot about a lot of things, we're geniuses who know everything about everything. And I'm probably as guilty of it as anyone else ...

      --
      The correlation between ignorance of statistics and using "correlation is not causation" as an argument is close to 1.
    2. Re:rhetorical question by SteveFoerster · · Score: 2

      You sound like Sinclair trying to convince G'Kar that he really didn't miss the right time to hold the G'Quan Eth ritual. But if it's good enough for G'Kar, it's good enough for me.

      --
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    3. Re:rhetorical question by jc42 · · Score: 3, Informative

      Furthermore, the thought that "the event really occurred X years ago" seems to assume a universal standard of time, independent of the location and velocity of the observer, by which far apart events can be ordered. But time is not like that is it?

      Well, yes and no. That can be true for events viewed by observers moving at a sufficiently high speed relative to each other. But this remote galaxy is probably only moving relative to us at a few hundred km/sec, which is a sufficiently slow speed that (for our purposes here) they can be considered in the same reference frame. In such cases, comparing time is simple (though perhaps not doable to nanosecond accuracy).

      An example on a smaller time scale: Light moves about 299 792 458 km in a second, and the Earth's diameter is about 12,742 km. So the Earth is approximately 43 light-milliseconds in diameter. Yet it's possible (if not trivial) to synchronize clocks on the Earth's surface to nanosecond precision, and there are communication protocols that keep them synchronized. The GPS system wouldn't work if this weren't possible, and those satellites are moving relative to us even faster than the Earth's surface or this supernova.

      One interesting use of this where such precision is critical is that astronomers sometimes combine the data from telescopes scattered around the world to make a large telescope with an effective aperture as wide as the Earth. Doing this requires measuring the arrival time of light waves with precision much better than 43 microseconds. The better precision, the less fuzzy the resulting images are.

      This is possible because all those telescopes have very small velocities relative to each other. The max relative speed of two objects on the Earth's surface is twice the rotation speed of a spot on the equator. That's such a small fraction of the speed of light that it's negligible, and they can be treated as being in the same frame to many more than 10 decimal places.

      If a remote astronomical object were moving at .99c relative to us, calculating relative times from both viewpoints would be complex and a bit strange to most people. But at relative speeds of .000001c or less, as with NGC 2655 and our galaxy, comparing times to within a few years is simple and straightforward (as astronomers measure such things ;-).

      --
      Those who do study history are doomed to stand helplessly by while everyone else repeats it.
    4. Re:rhetorical question by GNUALMAFUERTE · · Score: 2

      almafuerte@almafuerte-laptop:~/Desktop/android-sdk-linux_x86$ ping -c1 slashdot.org
      PING slashdot.org (216.34.181.45) 56(84) bytes of data.
      64 bytes from slashdot.org (216.34.181.45): icmp_req=1 ttl=241 time=197 ms

      Damn! I'm communicating with the past!

      Understanding time's true nature and the real effect that nature has on how we experience reality isn't simple. The fundamental question lies in whether we choose to refer to the actual event, or we choose to refer to the information about that event reaching us. Considering that everyday we refer to events happening in the present, when in reality light still takes time to travel any distance, regardless of how small, and therefore everything we experience is the effects of some past event, we should apply a consistent logic when dealing with this situations. Since the event is so far away that treating it as happening now or occurring 64 million years ago doesn't really change anything for us, and given that we find it convenient to refer to past events that happen close enough as "now", we should say that the event has just occurred, instead of pretending that saying it happened 64 million years ago changes anything for us.

      --
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    5. Re:rhetorical question by Anonymous Coward · · Score: 5, Informative

      In our frame of reference, it just happened recently

      That's not correct. Or at least that's not how simultaneity and past/present/future are defined in relativity, which seems to be what you're referring to with "frame of reference". I suppose you could define 'now' in that way... but that's not how it's defined in modern physics.

      In our inertial reference frame, it happened ~64 million years ago. In the star's reference frame, it also happened ~64 million years ago. It's true there is no such thing as a universal reference frame, so one can certainly construct inertial reference frames (e.g. with large velocities relative to us) where the event occurred at different times. Even 'now' (in that reference frame). But the velocity difference between us and the supernova is modest (in the grand scheme of the universe) and thus our two references frames roughly agree about simultaneity and so on.

      It's a strange misconception that people interpret relativity to mean that all space-time events on our past light-cone are 'now'. Relativity doesn't say that. It includes a well-defined concept about what is in the past, what is in the future, and the boundary between them being 'now'. We are not immediately aware of all space-time events on the 'now' plane... because it takes time for their signals to reach us. But when we receiving signals we are able to reconstruct and deduce what happened at previous moments. It is true that inertial reference frames do not agree on what 'now' means, and thus don't agree on simultaneity. But within a particular inertial reference frame, there is a meaningful concept of 'now'.

      Again, I suppose you could define 'now' in such a way, but it's not at all useful to think of the big bang happening 'right now' as we look far out into space. It makes much more sense to think in terms of it having happened 13.7 billion years ago, and we're only now receiving signals from the afterglow of the big bang from distant regions of space.

    6. Re:rhetorical question by mdielmann · · Score: 2

      And this is why simultaneous has a scientific definition. There is a frame of reference where any one of the three options (dinosaurs died first, star supernovaed first, both happened at the same time) is (more or less) correct.

      --
      Sure I'm paranoid, but am I paranoid enough?
  9. That's an old sketch. Here it is today. by Anonymous Coward · · Score: 5, Funny

    .

  10. Have we ever gotten something better? by Anonymous Coward · · Score: 2, Interesting

    Have we ever gotten something better than a few light plates worth of data from an in-progress supernova? I.e. an optical (false color or similar) shot of the thing going off?

    It would be fantastic if we could see the shockwave of matter grow and distort. The scale of the explosion should be easily identified but I suppose things may be too hot to image optically with known techniques?

  11. Sketches? by ddd0004 · · Score: 4, Funny

    Can't you just get the software they use on CSI Miami and click "enhance" like a million times.

  12. Wow Many amateur telescopes by Isaac-1 · · Score: 3, Interesting

    Translation, it is photographically within the reach of telescopes costing only a couple of thousand dollars, and from a good dark sky location visually within the reach of telescopes costing about as much as a typical reasonably nice used car (that is as a very dim pinpoint). The number of amateur telescopes in the world that can provide a decent view of this object is probably fewer than the number of people that will end up posting in this message thread.

    1. Re:Wow Many amateur telescopes by martinux · · Score: 3, Informative

      Magnitude 12.9 is quite visible to a 254mm (10 inch) newtonian (dobsonian) telescope that would cost you less than $600 if you picked one up second-hand. The trick is familiarising yourself with the night sky to be sure you're looking at the correct dim dot. ;)
      For thousands of dollars (and a lot of patience) you can discover them yourself using a computer controlled mount and a modest amount of aperture: Dave Grennan *discovered* a supernova from the outskirts of Dublin city using a 14 inch Cassegrain scope. http://www.science.ie/science-news/supernova.html

      https://secure.wikimedia.org/wikipedia/en/wiki/Limiting_magnitude#In_amateur_astronomy
      Magnitude calculator: http://www.cruxis.com/scope/limitingmagnitude.htm

      If only we could get more done about the horrible light pollution one wouldn't have to travel so far from urban areas.

    2. Re:Wow Many amateur telescopes by martinux · · Score: 2

      The illustration (in TFA) of 2011b was made with one of these (visually, of course):
      http://www.pulsar-optical.co.uk/prod/telescopes/sky-watcher/dobsonians.html
      (Please note I have no affiliation with the above company)

      As for seeing it as a faint cloud: What more do you want? Consider the image taken of supernova 2010 IK:
      http://cdn.thejournal.ie/media/2010/10/supernova1-478x377.jpg

      You're looking at something that's 290,000,000+ years old. Even a faint fuzzy is enough to appreciate the fact that light had to travel a somewhat lengthy distance to get to one's eye. I think a major problem with amateur astronomy is the unrealistic expectations of many newcomers. Images from professional observatories (including space-based telescopes) show large images with significant detail - some consider this to be 'what you see through a telescope' and don't think too much about the nature of the telescope in question.

      Educating people in what they're looking at and why it's so small goes a long way to improve their appreciation of the detail one can see through even a small telescope. :)

    3. Re:Wow Many amateur telescopes by Kentari · · Score: 5, Informative

      Photographically it is well within reach of DSLRs equiped with a 200mm lens. I managed to go down to magnitude 17 (or 100 times less bright) and even fainter with a Canon 20D and a 200mm f/2.8 lens, placed on a tracking mount and exposed for about 2 hours (accumulated in exposures of a few minutes). I'm sure it would even lie within the limits of a 50mm lens. The problem becomes distinguishing it from the host galaxy.

      Visually it was within reach of 4.5" beginner scopes at dark locations! These will set you back less than $200 nowadays. A $1000 12" would have produced very decent views of the SN together with it's host galaxy. There are a lot of telescopes of this size around. You obviously should take the time to visit a public observatory once.

  13. Re:relativity alert! by Urkki · · Score: 2

    The star exploded in January, not when the Dinosaur's were around.

    You've got some mighty fast photons then. I mean, just think, how long distance in our reference frame did the photons travel since January? Wow!

    Or if you're referring to a January 64 million years ago, I'm sure there are many scientists who'd love to see the math and observations, which let you calculate it was just January, and not for instance Terturary ;-)