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Supernova Casts Doubt on "Standard Candle" 132

Posted by kdawson
from the chandrasekhar's-the-limit dept.
Krishna Dagli writes, "A supernova more than twice as bright as others of its type has been observed, suggesting it arose from a star that managed to grow more massive than theoretically thought possible. The observation suggests that Type 1a supernovae may not be 'standard candles' — all having the same intrinsic luminosity — as previously thought. This could affect their use as probes of dark energy, the mysterious force causing the expansion of the universe to accelerate."
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Supernova Casts Doubt on "Standard Candle"

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  • by tttonyyy (726776) on Thursday September 21, 2006 @07:36AM (#16152636) Homepage Journal
    "twice as bright as others of its type"

    Obviously not a /. reader then. ;)
    • Yes, of their Type 1a [wikipedia.org] that is.
      • by ccarson (562931)
        I'm not an astronomer but I try to keep up on this stuff. Isn't this significant? Correct me if I'm wrong but don't they use the wavelengths and template makeup from type 1a novas to gauge the distance at which the explosion occurred? If 1a novas aren't all the same, which this article suggests, aren't the ramifications from this pretty big? Wouldn't this put into question not only the current map of the known universe but also whether the rate of universal expansion?
    • by Lissajous (989738) on Thursday September 21, 2006 @08:39AM (#16152944)
      "twice as bright as others of its type"

      Obviously not a /. reader then. ;)

      I don't get it.
  • Gravity Lensing? (Score:1, Insightful)

    by RyanFenton (230700)
    Could this be an effect of gravity of surrounding galaxies lensing [space.com] the light from a 'normal' large star in our direction and just appearing brighter?

    Ryan Fenton
    • Could this be an effect of gravity of surrounding galaxies lensing the light from a 'normal' large star in our direction and just appearing brighter?

      Or, for that matter, could it be a foreground star and not associated with that galaxy at all?

      • Not very likely since a massive star is short lived, and wont travel very far from it birth place in its short lifespan. Since a massive star obviuosly needs a lot of material, it cant very well be found outside a galaxy.
        • by LurkerXXX (667952)
          What if two (or more) not-so-massive stars collide outside a galaxy? Odds aren't great of it happening, but since the universe is so large, it's definitely going to happen somewhere.
        • by qeveren (318805)
          Type 1a supernovae aren't massive-star supernovae. They're accreting white-dwarf stellar remnants in binary systems. They can move a great distance from where they originated.
      • Re: (Score:1, Informative)

        by Anonymous Coward
        "...could it be a foreground star and not associated with that galaxy at all?"

        Simply put, no.

        A light spectrum clearly identifies a supernova for what it is. There is nothing else like it. Also, the redshift in the supernova and surrounding stars gives the distance fairly accurately.

    • by dknj (441802)
      i believe they have already factored that into the equation
      • by jdray (645332)
        Yeah, but did they factor in the idea that it could be the tailpipe of some alien spaceship heading away from us using some technology we're not aware of because we're too stupid to be useful and therefore scheduled for destruction to put in an interstellar bypass?

        I bet not!
    • by gutnor (872759)
      I wonder aswell but I guess ( I certainly hope ) that before putting some doubt on such a fundamental element of today science those professional astroner tooks the time to quickly discard most common reason for such a phenomenom: bad reading, bad calibration, lense effect, whatever other effect, ...
      Especially since the news seems to originate from Nature, and if it took only 6 min to find a slashdot reader with a sensible explanation, I suspect it would not have taken much more time within Nature Readers.

      B
    • Re:Gravity Lensing? (Score:4, Informative)

      by ByteSlicer (735276) on Thursday September 21, 2006 @08:45AM (#16152985)
      Probably not. Gravitational lensing would cause a noticible shift [wikipedia.org] in the star's spectrum.
      • Re: (Score:1, Interesting)

        by Anonymous Coward
        Probably not. Gravitational lensing would cause a noticible shift in the star's spectrum.

        And why would that be? Wouldn't the light be blueshifted as it fell into the gravitational potential of the lens, and then redshifted as it escaped, for a net spectral shift of zero?
        • Intreaguing question. Didn't consider the blueshift (mod me down :P).
          My gut feeling says that because the light trajectory was altered by gravity, there must be some effect on it's spectrum. But I would have to do some difficult calculations to see if my gut is right (it is, after all, a very dumb organ). Need more coffee...
  • by Anonymous Coward
    (note: I'm Canadian)
    Why is the telescope called "Canada-France-Hawaii" instead of "Canada-France-USA" telescope?
    Or did Hawaii separate from the US recently? ;-)

    Thomas Dz.
  • by Oligonicella (659917) on Thursday September 21, 2006 @07:49AM (#16152692)
    Models are just that, models. Change them when the universe shoves reality down your throat. Far too many people think that math defines the universe instead of describing it.
    • by rocketman768 (838734) on Thursday September 21, 2006 @07:55AM (#16152720) Homepage
      I think you are exactly right. I am a mathematician. People should understand that all of mathematics is an abstract concept created by humans. Why does 2+3 = 5? Because we said it does...not because it is universally true. Sometimes (in the case of 'models'), we put some math together to attempt to explain what we see. As we discover new behaviors in whatever system we're looking at, we have to change the math. So, this article is about one of those instances.
      • by MECC (8478) *
        "Why does 2+3 = 5? Because we said it does...not because it is universally true."

        While the notion that a mathematical model can be flawed is something that is easily conceivable, the "2+3=5 only true because of consensus" idea paints all of math as merely arbitrary, and I don't think it is. I think most, if not all, of math holds together rather well as an integrated system.

        • by KutuluWare (791333) <`gro.ulutuk' `ta' `ulutuk'> on Thursday September 21, 2006 @08:31AM (#16152892) Homepage
          I think his point would be more accurately expressed as this:

          "Why is 2 + 3 = 5?"

          Because the arbitrary definitions which we assigned to the symbols 2, 3, 5, +, and = happen to represent real-world concepts that exhibit the behavior that 2 + 3 = 5, and not because there is any abstract universal rule that "2 + 3 = 5" and we simply need to find real-world behavior to prove it. That is, the real-world behavior has always existed, but the mathematical language used to express it was invented by us and assigned to those behaviors specifically to make the mathematics true.

          (Or something, it's early.)

          --K
          • by inviolet (797804) <slashdot AT ideasmatter DOT org> on Thursday September 21, 2006 @09:23AM (#16153250) Journal
            Because the arbitrary definitions which we assigned to the symbols 2, 3, 5, +, and = happen to represent real-world concepts that exhibit the behavior that 2 + 3 = 5, and not because there is any abstract universal rule that "2 + 3 = 5" and we simply need to find real-world behavior to prove it.

            Quoted for truth. I want to elaborate (i.e. ramble) on it a bit . . .

            Numbers are indeed a deductive system: they are true because they are defined to be true. They are true in all conceivable universes. This makes them useful but also hollow: they contain no empirical content, and hence are immune to all conceivable experimental results.

            Nevertheless, they (and all other deductive symbols) can participate in inductive statements, such as "2 algae cells will combine with 3 fungi cells to produce 1 lichen".

            • by jdray (645332)
              Is that to say that the additive property of integers exists only because we've defined integers to be what they are? Seems reasonable to me. It makes me wonder how things would be different if we had (or even could have) decided to conceive of things in real numbers always.

              Ooohh... I just made my head hurt.
              • by c600g (30798)
                I believe that before numbers were in common use, it is thought that the concept of one/singular (e.g. me) and many (e.g. you all) was used. It was quite a leap to go to specific numbers, and a further leap to finally get the idea of zero/none. There was an interesting show on the Discovery|History channel about this a while back, I think.
              • by khallow (566160)

                Is that to say that the additive property of integers exists only because we've defined integers to be what they are? Seems reasonable to me. It makes me wonder how things would be different if we had (or even could have) decided to conceive of things in real numbers always.

                Integers are a natural way to count things. And they come embedded inside the reals as the real numbers generated by addition/subtraction over 0 and the multiplicative identity.
        • I think that those of us who have fingers can very easily define 2+3=5. There's nothing abstract about it, as if the numbers '2' or '3' were some sort of concept which could be defined in multiple ways depending on perspective. Can I by thinking about it, have 7 fingers instead of 5?
      • by The_Wilschon (782534) on Thursday September 21, 2006 @08:26AM (#16152864) Homepage
        So why is it that electric fields follow the law of superposition, which is an additive law working precisely as we said addition should thousands of years before we ever imagined electric fields? Furthermore, how is it that we can "prediscover" phenomena? We develop a model to describe existing data, and whoops!, there's another phenomenon implicit in our model, and sure enough when we look for it in reality, there it is!

        This is a fairly poor summarization of the argument made by Tom Siegfried (used to be chief science writer for the Dallas Morning News, now he's somewhere else) in his book Strange Matters.

        Perhaps you are right, and mathematics is just something we came up with. However, where did we come up with it from? Our brains. Our brains are part of the universe, so if the universe is goverrned by laws which can be well expressed in mathematical language, one might predict that brains would invent mathematics.
        • Perhaps you are right, and mathematics is just something we came up with. However, where did we come up with it from? Our brains. Our brains are part of the universe, so if the universe is goverrned by laws which can be well expressed in mathematical language, one might predict that brains would invent mathematics.

          There's little need for such an elaborate argument. Mathematics is something we came up with to describe and quantify the world we see around us. The fact that mathematics is so good at describing

          • Re: (Score:3, Insightful)

            by saider (177166)
            That the area of a triangle inscribed in a circle is equal to the product of its three sides divided by four times the circles radius is a physical fact...

            Only for perfectly flat space. In reality, all space is curved even if by just a little bit.

            We generally discover that what we believe to be a fundamental truth is often dependant on assumptions that we are not aware of. This is where brilliant minds discover more about our world by exposing these hidden assumptions.

            Also, we tend to aggregate things for c
            • by jdray (645332)

              That the area of a triangle inscribed in a circle is equal to the product of its three sides divided by four times the circles radius is a physical fact...

              Only for perfectly flat space. In reality, all space is curved even if by just a little bit.

              So your argument is with the physical fact part and not the rest, right? The description of the method for determining the area of a triangle is indeed fact where mathematics is concerned. Math, when applied to the real world, loses a certain amount of its ef

            • by Burz (138833)
              Yet apples are more than just a human concept; they are a class of real objects. Without classes (belonging to sets) we can't have numeracy. So we would have to ask whether the cosmos itself accomodates classes on a fundamental level. Looking at the subatomic world, I'd say it does. The underlying uniformity gives rise to increasing uniformity and predictability at higher levels, larger connected scopes of space, energy/matter and time... until we get to the point where we can count apples and stars with in
            • by AJWM (19027)
              but that is not what it really is. 2+3 works for most cases, but there will be edges where the simpler math breaks down and if you do not realize that you are dealing with quantum particles instead of a few apples,

              Case in point: let X be 0.25 critical masses of plutonium. 2X + 3X doesn't equal 5X, at least not for very long.

              you may become very frustrated.

              Or dead.

              (And for the nuclear physicists and engineers: yes, I know it's more complicated than that because of factors like shape, etc. substitue "pluton
          • by Control Group (105494) on Thursday September 21, 2006 @10:08AM (#16153662) Homepage
            This is certainly true, but don't undersell math, either. The amazing part of math is that, given certain axioms and definitions crafted to describe and fit easily-observed physical phenomena, logical extrapolations of those axioms and definitions can accurately describe physical phenomena we have not yet observed.

            That is, mathematics is not purely descriptive as it relates to science. As an example, it is my understanding that the phenomenon of time dilation as velocity increases towards c was first "observed" as a result of mathematical manipulations of exsiting models, long before it was (or could be) experimentally observed.

            If math were purely descriptive, this would not be the case - or, if it were, it would be only by sheerest chance; the exception, rather than the rule.

            I agree, of course, that math comes out of description; 2+3=5 because those numbers represent specific physical quantities, and when you have real items in those quantities, they behave in that fashion. However, I can't help believing that there is something inherently "real" about math itself, since the logical structure of math agrees so well with physical reality so often - enough so, in fact, that the mathematical understanding of a physical phenomenon can predate observation of that physical phenomenon.
            • by Kjella (173770)
              That is, mathematics is not purely descriptive as it relates to science.

              Math is just barely descriptive to science, the tables of values in my thermodynamics class was purely descriptive to science. But by the time you've gotten so far that you have mathemathical formula, it's essentially predictive. If we know that f(x) holds for x_min...x_max, the prediction would naturally be that it holds for 0.5*x_min or 2*x_max. If we know two formulas, the prediction would also be that f(x,y) = f(x) + f(y). Of course
            • by Thuktun (221615)

              The amazing part of math is that, given certain axioms and definitions crafted to describe and fit easily-observed physical phenomena, logical extrapolations of those axioms and definitions can accurately describe physical phenomena we have not yet observed. [...] If math were purely descriptive, this would not be the case [...]

              This is logically fallacious. If a mathematical model predicts previously-unknown real-world behavior, it is either descriptive of the world or it is prescriptive. While it might

              • Point taken; perhaps my use of the word "descriptive" is in error. I was using the term in opposition to "predictive," with the intended denotation to be that "descriptive" usage occurs after observation (the thought being that one can only describe what one has observed), while "predictive" usage occurs prior to the observation.

                I am open to suggestions as to what pair of words I should have used instead.

                Regardless of my possible misuse of terminology, I maintain that math's predictive power implies a reali
            • by gstoddart (321705)

              This is certainly true, but don't undersell math, either. The amazing part of math is that, given certain axioms and definitions crafted to describe and fit easily-observed physical phenomena, logical extrapolations of those axioms and definitions can accurately describe physical phenomena we have not yet observed.

              Aren't there sub-atomic particles which were believed to exist due to a negative square root or something?

              As I recall, they have been borne out by experiments.

              That just hurts my head. :-P

              Cheers

          • by Randolpho (628485)

            properties that we "prove" are simply physical facts, that exist independant of our ability to make theorems. That the area of a triangle inscribed in a circle is equal to the product of its three sides divided by four times the circles radius is a physical fact, not resulting from our mathematical manipulations, but one which our mathematics can only "prove" because they correctly describe and quantify all of the geometrical entites involved. And they do this beacause we built them to do that.

            To expand o

        • by lawpoop (604919)
          Real-world measurements don't exactly work out the way you would have us believe.

          "So why is it that electric fields follow the law of superposition, which is an additive law working precisely as we said addition should thousands of years before we ever imagined electric fields?"

          Except when you actually do the measurements, you get a slight variance. Why should we get some discrepancy? I thought this was precise mathematics, proven sturdy for thousands of years. 'Well,' the answer goes, 'the measurement
          • by gardyloo (512791)
            Real-world measurements don't exactly work out the way you would have us believe.

            "So why is it that electric fields follow the law of superposition, which is an additive law working precisely as we said addition should thousands of years before we ever imagined electric fields?"

            Except when you actually do the measurements, you get a slight variance. Why should we get some discrepancy? I thought this was precise mathematics, proven sturdy for thousands of years. 'Well,' the answer goes, 'the measurement tool
            • by lawpoop (604919)
              I admit you caught me -- I don't specifically know about "law of [linearj] superposition of electric fields", but any measurement I've seen of the real world has some small degree of divergence from the formulas -- small in orders of magnitude. The official line is that this variance is due to the imperfection of lab setup, imperfection of materials measured, and the imperfection of the measuring equipment.

              I suspect that most phenomena don't 'measure up' quite as exactly as electrical fields. If that's
              • by gardyloo (512791)
                I admit you caught me -- I don't specifically know about "law of [linearj] superposition of electric fields", but any measurement I've seen of the real world has some small degree of divergence from the formulas -- small in orders of magnitude. The official line is that this variance is due to the imperfection of lab setup, imperfection of materials measured, and the imperfection of the measuring equipment.

                I'm generally agreed. On the other hand, most experimentalists (and many of the
              • by be-fan (61476)
                So you don't actually know anything, you're just speculating pointlessly?
        • Re: (Score:3, Insightful)

          by maynard (3337)
          Furthermore, how is it that we can "prediscover" phenomena? We develop a model to describe existing data, and whoops!, there's another phenomenon implicit in our model, and sure enough when we look for it in reality, there it is!

          I suspect this is like our response to red traffic lights. We remember the annoyance of having to stop, but rarely remember all the times we sail through a green light. Often, people will complain about 'bad luck' with red lights as a result. But the reality is that the red lights a
      • by kalirion (728907)
        Why does 2+3 = 5? Because we said it does...not because it is universally true.

        I don't know about that. I am not a mathematician, but I've always been pretty sure that we defined numbers and addition, but specific instances of their usage, like "2 + 3 = 5" are not defined but instead logically induced (or deduced, I forget) from those base definitions. And given the base definitions, 2+3=5 is universally true.
        • by TheRaven64 (641858) on Thursday September 21, 2006 @09:10AM (#16153154) Journal
          And given the base definitions, 2+3=5 is universally true.

          2+3=5 is not univserally true, it is true within the framework of a common set of axioms. Here is an example of a simple set of axioms which allow us to prove that 2+3 = 5 (within the framework of those axioms):

          Let s(X) be the successor function applied to the variable X.
          Let 0 be a symbol in our algebra.
          Let 0 = 0. (1)
          Let s(X) = s(X) if and only if X = Y. (2)
          We now have equality defined.

          Let X + 0 = X. (3)
          Let X + s(Y) = s(X) + Y. (4)
          Let X + Y = Y + X. (5)
          We now have addition defined.

          We define a set of symbols such that 2 = s(s(0)), 3 = s(s(s(0))), and 5 = s(s(s(s(s(0))))).
          2+3 = 5 is therefore equivalent to s(s(0) + s(s(s(0))) = s(s(s(s(s(0))))).

          We can rewrite this by applying our axoims (axiom number given in brackets) so that:
          s(s(s(0))) + s(s(0)) = s(s(s(s(s(0))))) (4)
          s(s(s(s(0)))) + s(0) = s(s(s(s(s(0))))) (4)
          s(s(s(s(s(0))))) + 0 = s(s(s(s(s(0))))) (4)
          s(s(s(s(s(0))))) = s(s(s(s(s(0))))) (3)
          s(s(s(s(0)))) = s(s(s(s(0)))) (2)
          s(s(s(0))) = s(s(s(0))) (2)
          s(s(0)) = s(s(0)) (2)
          s(0) = s(0) (2)
          0 = 0 (2)

          This gives axiom 0, and so is true.

          Anyone wanting to play with these ideas in a more hands-on way should download a prolog implementation (I recommend SWI Prolog [swi-prolog.org]). You can implement these axioms in prolog as the following program (the first two are implicitly defined):

          % add(X,Y,Z) predicate represents X + Y = Z
          add(X,0,X).
          add(X,s(Y),Z) :- add(s(X),Y,Z).
          add(X,Y,Z) :- add(Y,X,Z).
          You can then ask it questions in the following way:
          ?- add(s(s(0)),s(s(s(0))),Five).

          Five = s(s(s(s(s(0)))))

          Yes
          Your homework from this post is to extend this system to define multiplication.
          • by kalirion (728907)
            Me: And given the base definitions, 2+3=5 is universally true.
            You: 2+3=5 is not universally true, it is true within the framework of a common set of axioms.

            Now I think it should be obvious that by "base definitions" I pretty much meant your "common set of axioms", though of course I couldn't write out the exact axioms without doing some reasearch. And in my post I forgot that besides numbers and addition we also needed to define equality. So given the definitions, or the framework of a common set of axiom
      • by Bemopolis (698691)
        "Why does 2+3 = 5?" It doesn't — 2+3 = 10.

        You have to understand, my math teacher only had one hand.

        Bemopolis
      • by pmancini (20121)
        Its also well know that 2+2 = 5

        for very large values of 2.
        • by stevey (64018)

          Its also well know that 2+2 = 5

          for very large values of 2.

          Or very small values of 5.

      • by idonthack (883680)
        Why does 2+3 = 5? Because we said it does...not because it is universally true.
        So, if I said that you were a carrot, it would be correct because I said so? Even if it weren't universally true, you would still be a carrot. I could grate you and put you in a salad, like any other carrot.
        • by Randolpho (628485)

          Why does 2+3 = 5? Because we said it does...not because it is universally true.

          So, if I said that you were a carrot, it would be correct because I said so? Even if it weren't universally true, you would still be a carrot. I could grate you and put you in a salad, like any other carrot.

          No, if you said he was a carrot, you would be placing a label, "carrot", upon him. That label is external to the actual himness of him.
          2 is a label for a quantity. 3 is a label for a quantity. 5 is a label for a quantity

        • so, if I said that you were a carrot, it would be correct because I said so?

          No, but any deductions that you came up with would be true, provided that you accept that he is a carrot.

      • by bigpat (158134)
        Why does 2+3 = 5? Because we said it does...not because it is universally true.

        Wouldn't it be universally true because it is consistent with what has been defined? That is precisely what is so useful about mathematics in science, it is not dependent on observation, but merely needs to be consistent with simple rules that have been defined. In science, mathematics is used as a reference system.

        Certainly mathematics started as a way to describe real world phenomena, but its definition is no longer linked to
      • by aug24 (38229)

        People should understand that all of mathematics is an abstract concept created by humans.

        What utter cobblers.

        Consider that other animals show the capacity to do maths. Monkeys are surprised when, for example, a box is shown to them containing two apples, then another three apples are put in a box and when the box is opened there are only four in there. They have understanding of addition, subtraction and probably commutation.

        A lot of mathematics is stuff the brain (human or animal) has observed

      • If the universe does not work on principles of logic (and hence mathematics), then fairies and pink unicorns do roam the plains of Nebraska, while miracles occur via Mother Theresa, and Jesus walks on water. I mean what business are scientists in if they don't think that the universe follows some order? To say it follows this or that order some of the time is just crazy right? If things can happen in the universe without any cause or reason, then what is the point of science? What exactly are we investi
    • by kfg (145172) *
      But, but, there was a consensus. To go against the consensus isn't, ummmmmmmm, well, politics.

      KFG

    • Far too many people think that math defines the universe instead of describing it.

      I find that not at all odd, given how mathematics have proven unreasonably effective [wikipedia.org] in describing the universe we find ourselves to be a part of. Or so I feel. Math feels a little bit like magic to those who don't have a firm grasp of it. Hell, I have a decent grasp of mathematics in general, but it still seems a bit mystical to me. Sort of. Disclaimer: My worldview is entirely naturalistic. I'm not describing my reasoned

      • by inviolet (797804)

        I find that not at all odd, given how mathematics have proven unreasonably effective in describing the universe we find ourselves to be a part of.

        Yep yep. Mathematics makes possible the completely astounding feat of being able to build a bridge out of precise amounts of raw materials, knowing ahead of time exactly how much wind and weight it will ultimately be able to bear.

        Of course, any engineer worth his salt will build his bridge out of Rearden Metal . . . :)

    • by Nereus (733242)
      All models are wrong, but some models are useful. - George Box
    • by el_womble (779715)
      The difference between theory and practice is that in theory there is no difference, but practice there always is. -- Someone far cleverer than me

    • That's the Platonist viewpoint, that mathematicians are discovering mathematical truths that already exist, rather than constructing them out of a formal system. A mathematical reality exists independently of us, and of anything. We, as imperfect beings can only get close to it, to approximate it {perhaps with these things called models}. This view was quite popular among mathematicians until the 20th century turn on objectivity. Gödel is an example of a Platonist.
    • Re: (Score:3, Interesting)

      by Jeff DeMaagd (2015)
      There have already been doubts about the uniformity of brightness of a supernova. Some people think that non-polar and non-equatorial viewpoints are possibly less brigtht than polar or equatorial views.
    • by Speare (84249)
      • An engineer thinks that aside from imperfect materials, the models approximate reality,
      • A physicist thinks that aside from sensor unreliability, reality approximates the model,
      • A mathematician doesn't care.
  • by trip11 (160832) * on Thursday September 21, 2006 @08:08AM (#16152766) Homepage
    ...as supernova are not well understood. First off I am not an astrophysicist, though I am a high energy physicist (and have taken some astro classes). One thing that has been discussed in nuclear classes I have taken is how little we understand just how a supernova functions at the atomic level. The number of competing effects going on during the collapse of a star is just amazing. You have gravitational pull, thermal pressure, rotational 'pressure', electromagnetic forces in a regular star. Now you start to collapse the star and you have to add in the transition of millions of individual nuclei becoming in effect one large nucleous as they all mearge. (not to mention the energy output from this). In effect the strong force comes into play along with the standard EM and gravitational forces. It gets much more complicated than that, but it has been several years since those classes.

    So why do I think this is a 'good thing'? As the article speculates, it is likely that this supernova was different because of some rotational process or perhaps colliding stars, or some other exotic combination. This is exactly the sort of process that can be used as a test of supernova models to see how well they do. Over all I find this a very exciting observation and hopefully it produces more new science!

    • by inviolet (797804)

      The number of competing effects going on during the collapse of a star is just amazing. You have gravitational pull, thermal pressure, rotational 'pressure', electromagnetic forces in a regular star. Now you start to collapse the star and you have to add in the transition of millions of individual nuclei becoming in effect one large nucleous as they all mearge. (not to mention the energy output from this). In effect the strong force comes into play along with the standard EM and gravitational forces. It get

  • by i_should_be_working (720372) on Thursday September 21, 2006 @08:09AM (#16152771)
    The observation suggests supernovae of this type are not "standard candles" as previously thought, which could affect their use as probes of dark energy - the mysterious force causing the expansion of the universe to accelerate.

    If true, this wouldn't just affect their use as probes of dark energy. These standard candles are used to tell how far away things are and how fast they are moving. The age of the universe could be in doubt.

    But I have a hunch this particular supernova will turn out to be an anomaly. Not that I'm a astrophysicist or anything.
    • by The_Wilschon (782534) on Thursday September 21, 2006 @08:38AM (#16152941) Homepage
      I doubt it. Our actual measurements of dark energy won't come under much increased doubt. Although Type IA supernovae the first (IIRC) indicator of dark energy, we still have a number of other indicators. I was just as PASCOS 2006, and saw several talks on dark energy, where various quantities related to the acceleration of the universe were really overconstrained by about 4-5 different measurements. The only one I can recall at the moment is gravitational lensing. The neat thing is that although overconstraint has the possibility to show an inconsistency, it doesn't do so here. The measurements all line up at one point (well, a distribution around one point, but that distribution is quite nicely peaked in one location, indicating consistency.).

      Similarly, Type IA SN are not the only mechanism by which we measure the age of the universe, so I'm not too concerned. The other reason I'm not too concerned is that the age of the universe was already in doubt. Another talk at PASCOS dealt with something else that I can't recall at the moment (curse my memory in the morning!) that cast into simultaneous doubt all or nearly all of our universe age indicators. IIRC, according to his talk, the universe could well be 20% older than our current best estimate.

      Of course, since all these are not quite my field (I was at PASCOS for the particle physics), I can't answer for whether or not these guys were just crazies and all the cosmologists were ignoring them, or if these are serious problems that will be dealt with in the next few years. I'd be inclined, however, to assume that they were quite legit.
      • That's comforting that not too much depends on these supernovae. I had thought they were the beginning and end to many of the measurements we have on the universe.
    • Aside even from the age of the universe, at stake would be whether the universe is in fact expanding at the widely understood rate, or perhaps whether the universe is expanding at all. IOW at stake again is the question of ultimate fate.

      It seems in TFA that astronomers do have some data to reevaluate, toss, and that these fundamental calculations could be in flux. This is exciting, we might not be expanding to oblivion, instead we might be contracting to oblivion like we thought we were before! Knowledgea

    • by tehcyder (746570)
      The age of the universe could be in doubt.
      But I thought everyone knew that the universe is now 6010 years old?
  • This is astronomy. Astronomers are generally happy getting thing to an order of magnitude. I am not sure one supernova that is twice as bright is going to change things that much.

    Disclaimers: IRAAA (I really am an astronomer), but I know nothing about using SN as standard candles (other than the fact that they are used...). No, I did not RTFA.
  • http://www.proton21.com.ua/ [proton21.com.ua]

    They simulated a micro super nova here

    Producing micro fussion/fission and creation of new materials.
  • by StupendousMan (69768) on Thursday September 21, 2006 @08:13AM (#16152793) Homepage
    I study supernovae for a living.

    The Nature paper in which this work is published has a figure showing all the measurements of this supernova's brightness; you can see it on Nature's web site at

    http://www.nature.com/nature/journal/v443/n7109/fi g_tab/nature05103_F1.html [nature.com]

    There are four measurements near time of maximum light, in the red (r) and near-infrared (i) passbands. There are many more measurements starting about 15 days after maximum light in the rest frame, including some in a blue-green (g) passband. Here's what the researchers did to find the maximum brightness of this supernova, so that they could compare it to others:

        a) fit models based on the light curves of other supernovae to the r and i measurements,
                      and the late-time g measurements

        b) choose a different passband -- the greenish V passband of the Johnson-Cousins system,
                      which is closest to their own g passband (the one with no data at max light)

        c) use their models to estimate what the light curve in the V filter would have been

    This can be a tricky business. Their major conclusion, that this supernova was more luminous than typical ones, is probably correct, but their claim that they can measure the peak magnitude in the V-band to an uncertainty of 6 percent seems a bit bold.

    As the press release states, if atypical SNe are very rare, then this probably doesn't have any major impact on the use of Type Ia SNe in cosmology.

    • by JonnyCalcutta (524825) on Thursday September 21, 2006 @09:15AM (#16153200)
      So what you are saying is....eh....the thing with the........when the thing with the other thing goes...to.....because the wotsit is like the..eh....so, do they run Linux in their lab?
    • Question for you: These Type 1a Supernova are used as one step on the distance ladder, correct? So if we no longer believe they all have the same brightness, that means the distance we have on record for many objects is now wrong?
      • Re: (Score:3, Insightful)

        by StupendousMan (69768)


        These Type 1a Supernova are used as one step on the distance ladder, correct?

        Type Ia supernovae are indeed one of the last rungs on the distance ladder; they can be used to estimate distances to very distant galaxies.


        So if we no longer believe they all have the same brightness, that means the distance we have on record for many objects is now wrong?

        No, that's an overstatement. Type Ia supernovae are one of several different indicators used to estimate distances to very distant galaxies -- not the only

  • by rucs_hack (784150) on Thursday September 21, 2006 @08:15AM (#16152800)
    It's a pretty familier story, and essential for the advancement of science.

    The standard candle was a theory, one that worked well, and now it's in doubt, indicating either that its wrong, or it's incomplete. I'd vote for the latter personally.
    That's usually a safe bet...

    That's how things move forward.
    I shortcut this process. I proved one of my hypothesis wrong even though it had withstood initial tests which indicated correctness. It probably saved a lot of time, but lost me a conference trip, dammit.
    • >It's a pretty familier story, and essential for the advancement of
      >science.

      Sure, just like the ever-changing O.J. defense team theories in response to found evidence were essential to the advancement of justice ;)

      Now if you could actually do experiments, that would be pretty cool. I want to don the tinfoil glasses for the first supernova trial in the lab ...
  • dark energy, the mysterious force

    Dark energy? the mysterious force? Oh, I get it, we found the death star [wikipedia.org]!

    That was funny right? *nudge**nudge*

  • Lukas Rossi won (Score:1, Offtopic)

    by ylikone (589264)
    Can we stop talking about Supernova now? Besides, I really don't think this band has the ability to think about or comment on things such as "standard candle"... oh wait... wrong site... sorry
  • Skeptical... (Score:2, Interesting)

    by Anonymous Coward
    Two points:

    1) Never trust anything you read in New Scientist.

    2) Consider the following, discovered on Google:

    In section 5.4, for the SNe that were thrown out, are you sure that all of them had enough data to accurately measure the peak? I was just looking at SNLS-03D3bb, and there are only 3 or 4 points in in g-band (restframe B), and they are all >~ 20 days after maximum light. So the B-band measurement here is a total extrapolation. Also, in the fits Julien gave me I think it was 0.4 mag off, not

    • 1) The slashdot title, and a line in the New Scientist article are misleading. This does not cast doubt on SNe Ia as standard candles. It is an odd supernova, but we think we can screen these out -- we just have to be careful.

      2) That email refers to observations in the B filter, which are used for cosmology. Indeed there is not enough data from that g filter (which transforms to B) near peak to constrain this supernova, so it was thrown out from the cosmology partially because the B peak magnitude is a c
    • by tehcyder (746570)
      Never trust anything you read in New Scientist
      Absolutely, googling for out of context quotes on the web is far more likely to give you a balanced accurate view of things.
  • Since when do these guys [msn.com] know anything about astrophysics?
  • Why does the article not mention when the supernova was observed (date or time) nor where in the night sky it was observed? I would think that'd be something the author would expect people would want to know, no?
  • > "A supernova more than twice as bright as others of its type
    > has been observed, suggesting it arose from a star that
    > managed to grow more massive than theoretically thought possible

    Assuming the theory is correct...Contact! You heard it here first! [wikipedia.org]

    Sci-fi is replete with civilizations that are messing around with black holes and supergiant stars and crap.
  • I've never heard of Standard Candle, but I really don't know what Supernova [wikipedia.org] would have against them.

    Perhaps they're still miffed that Tommy Lee et al borrowed their name for a reality show recently...

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