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Space The Media Science

Betelgeuse To Blow Up Soon — Or Not 312

rubycodez writes "A wave of 2012-related hoopla has hit the internet about the star that makes the 'right shoulder' of Orion the hunter: Betelgeuse. Astronomer Phil Plait once again puts rumors to rest. The star will indeed explode as a type II supernova, and when it does it will be brighter than Venus when viewed from Earth, though not as bright as the full moon. It will be visible in the night sky for weeks, and could be visible in the day sky for a short time. But that event could happen today or 100,000 years from now, or as much as a million years from now. Since Betelgeuse is over 600 light-years away, its violent death will not harm Earth in any way, but will definitely provide a huge bonanza of scientific information about supernovae. As geeks, we can only hope the core of Betelgeuse undergoes catastrophic failure in our lifetime."
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Betelgeuse To Blow Up Soon — Or Not

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  • Soon? (Score:4, Informative)

    by RabbitWho ( 1805112 ) on Saturday January 22, 2011 @03:15PM (#34967032) Homepage Journal
    What they're saying is it might have blown up around 600 years ago... or not
    • Re:Soon? (Score:5, Insightful)

      by Anonymous Coward on Saturday January 22, 2011 @03:21PM (#34967076)

      To you and the other 17 people who have already stated this and who will state this, we know. But we don't mention it, because it's irrelevant. Some of those who state it are just pointing out an interesting fact, which is fine, but to those who are stating it like it changes the story itself, or the importance of the story, or the facts of the story--shut up.

      • If i had known so many people were going to say it I wouldn't have said anything. I feel like a bit of a drone now. But it's the first thing that came into my head when I saw the headline.. "Isn't betelgeuce the past?" I said to myself. Oh well.
        • by icebike ( 68054 )

          If i had known so many people were going to say it I wouldn't have said anything.

          Hey, somebody was sure to state it, and getting it in up front wards off all the redundant posters (hopefully).

          Perhaps not on Slashdot, but definitely in the general population the majority of people are so far away from understanding this fact that they may have already posted the same thing and we simply won't see if for a X number of posts or several life times.

        • Well... if nothing can exceed c, then does the state of things beyond that really matter to us?

          • Well... if nothing can exceed c, then does the state of things beyond that really matter to us?

            Technically incorrect, and for some reason this is a common mistake. Einstein's theories dictate that nothing can go as fast as c . I'm not saying there is anything that can go faster, just that that's not what his theories say. Relativity says nothing about faster than c.

            • Re:Soon? (Score:4, Informative)

              by ultranova ( 717540 ) on Sunday January 23, 2011 @09:41AM (#34972798)

              Einstein's theories dictate that nothing can go as fast as c.

              Actually, no: they are based on the observation that the speed of light relative to you doesn't change as you accelerate, which of course means that you can never catch it.

              And of course your statement is incorrect anyway, as light is something and goes as fast as c. So do all massless particles, for that matter. So do chances in electromagnetic and gravitational fields.

              Relativity says nothing about faster than c.

              Relativity states that to go faster than c is to travel in time. In other words, things going faster than c will violate causality. That's pretty much up there with point out that something results in perpetual motion engines, as far as strength of refutations go.

            • Einstein's theories dictate that nothing can go as fast as c . Relativity says nothing about faster than c.

              You're entire point is basically the distinction between >= and >?

              Tell me, how would an object arrive at a velocity greater than c without either reaching c or undergoing infinite acceleration?

      • Re:Soon? (Score:4, Interesting)

        by justin12345 ( 846440 ) on Saturday January 22, 2011 @04:43PM (#34967658)
        I have a serious question about the speed of light, and our ability to determine the relative distance and speeds of stellar objects. I specialized in the arts not the sciences, so maybe one of you physics buffs can help me. Please humor me if these are the dumbest questions in the world.

        How do we actually know that the wave/particle/whatever I see when I glance up at Betelguese is about 600 years old. It seems to me that we would need to know a few things first, before we could calculate that:

        How fast is the Earth moving through space? Not toward or away from Betelguese as in red and blue shifts of that particular star but just how fast are we moving through space in general. Can we look at one part of the sky and see everything red shifted and another part of the sky and see blue shifted and extrapolate the total speed from that (obviously we would need a series of measurements)? Do we know how fast the galaxy is moving, or even the speed that the sun moves around the center of the galaxy? For instance if I'm driving a car east at 60 mph, can we take all those factors, add them together and determine the total speed of me and my car.

        Does that combined speed cause a time dialation effect (even a tiny one) on Earth? I know time and mass becomes distorted as you approach the speed of light, but I've never heard how steep that gradient is or if there is a lower limit. Would a hypothetical stationary cup of water cooled to absolute zero experience time differently then a similar cup boiling at 100 degrees (obviously the difference would be very tiny, but would it be there or is there a cut off)?

        If the universe is expanding in the sense that there is more space between all particles (this was how it was explained to me: that with each passing moment the distance between all particles increases as the fabric of space-time slowly expands) wouldn't the speed of light be slowly increasing (or decreasing) as well. Would a lightyear 600 years ago be the same as it is now?

        I know that the margins of error in determining astrological distance are way larger then any of these factors, and wouldn't effect the "about 600 lightyears away" distance of Betelgeuse. I'm asking more hypothetically. "Are these even factors?" is what I'm asking. What do we know and what don't we?

        It's kinda hard to find the answers short of getting an astrophysics degree, so I'm hoping someone here with one could help me out.
        • I'm pretty sure you're wrong about the last part. All those questions have been discussed and argued extensively for decades by people who spend disproportionate amounts of times thinking about them... to the point where the "answers" can be found on wikipedia. I'm not a physicist, so I won't answer you unless noone else does, I really like your set of questions though.

          • The difficulty with the last part is the contradictory nature of the info when you ask these questions to a search engine. Though your Google-Fu might just be much better then mine, too.
        • Re: (Score:2, Interesting)

          The questions you raise are valid. We don't know how long it takes a photon to get here from Betelgeuse down to the nearest second. For stars which are fairly close astronomers can use parallax to get a precise distance. They do that by measuring the position of the star in the sky six months apart with the orbit of the Earth around the run providing a baseline. I don't know if they can do that for Betelgeuse. It might be a bit too far away. Beyond that they rely on measuring the brightness and spectrum of

          • Re: (Score:2, Informative)

            by Anonymous Coward

            Relativity says that the photon coming from Betelgeuse experiences no time when it travels those 600 light years. So the travel time is zero. If we see the star explode in 2020 then it would have exploded in 2020.

            IANAP but light does have a travel time: the speed of light is finite. However, the photon does not experience travel time because it's travelling at the speed of light.

        • by jc42 ( 318812 )

          JFGI ;-) Try "solar system" and "motion" as the search terms.

          You can find some of the numbers for the Solar System's orbit at wikipedia [wikipedia.org]. Scan the page for "Solar System". Thus, in the "Sun's location and neighborhood" section, it mentions that our orbital speed around the center of the galaxy is about 220 km/s, roughly in the direction of Vega. At that speed, relativistic effects are measurable, if you have good astronomical instruments, but you probably can't detect the effects with your own senses.

        • by turgid ( 580780 )

          If the universe is expanding in the sense that there is more space between all particles (this was how it was explained to me: that with each passing moment the distance between all particles increases as the fabric of space-time slowly expands) wouldn't the speed of light be slowly increasing (or decreasing) as well. Would a lightyear 600 years ago be the same as it is now?

          All particles are not moving apart from one another. Some are. Those within atoms are not, and the expansion of the universe does res

          • Thanks, I wasn't even thinking about the electromagnetic forces. Though isn't there a point (going by the heat death theory), that space-time expansion will overcome the electromagnetic forces? Or is that too controversial still?
        • Re:Soon? (Score:5, Informative)

          by Kjella ( 173770 ) on Saturday January 22, 2011 @06:04PM (#34968190) Homepage

          Long story short, our full motion is measured relative to the background radiation. The earth rotates around itself, around the sun, the sun rotates around the milky way and the milky way is moving itself. In total we move about 0.2% of lightspeed, and time dilation is relative to the fraction of c squared so time goes about 0.0004% faster than at rest. Imagine you stuck your finger in still water, the circle it'd make would continue to grow and the wave would go on forever but get thinner and thinner. Same thing with the universe, the distance to the edge keeps increasing but the earth and moon isn't being pulled apart by space "stretching". All this is really on a much grander scale though, in terms of a planet 600 light years ago it's like asking if you can find your way down to the corner store without taking into account that earth is round.

          The difficulty is in trying to get an accurate angle measurement, even taking pictures from both sides of the earth we only get a ~13000 km wide angle which is small when you're trying to see an object ~5000000000000000 km away. For Betelgeuse wikipedia lists the distance as 643 ± 146 ly so the uncertainty is almost 300 ly. If we could travel even a tiny bit in any direction that'd matter on a stellar scale and photograph the sky we'd have much, much, much better estimates on the distances. That said, we can still do a lot more from earth or near earth than we have so far and there's plans for far better telescopes than today, first up probably the James Webb Space Telescope in 2014 or 2015. Also ground based telescopes keep getting larger and better, even though the atmosphere limits them somewhat.

          • Re:Soon? (Score:5, Informative)

            by Ruie ( 30480 ) on Saturday January 22, 2011 @07:32PM (#34968806) Homepage
            Stellar parallax [wikipedia.org] is usually measured using positions of the earth at different points of the orbit around the sun, which provides a much longer measurement base.
          • The difficulty is in trying to get an accurate angle measurement, even taking pictures from both sides of the earth we only get a ~13000 km wide angle which is small when you're trying to see an object ~5000000000000000 km away.

            We don't take pictures from both sides of the Earth - we take pictures from each side of the Earth's orbit. (I.E. six months apart.) Thus the baseline is (roughly) 300,000,000 km, not 13,000 km.

        • Re:Soon? (Score:4, Informative)

          by guruevi ( 827432 ) on Saturday January 22, 2011 @06:09PM (#34968230)

          I would suggest you to read Einstein's "Relativity: The Special and General Theory". He explains it pretty well. It's available for free from a number of sources as part of Project Gutenberg (free on iTunes Book Store, 0.99 for the Kindle, ...).

        • As an art specialist, you know about stuff like parallax. When you move from side to side, object appear to move. The further away an object is, the less it appears to move. By comparing pictures of a star taken six months apart (when the Earth has moved to the opposite side of the Sun), astronomers and astrometric scientists, measure how far a star has moved relative to the background stars, and can determine how distant the star is [bbc.co.uk].

          Another thing you are probably aware of is the inverse square law.
        • Re: (Score:2, Informative)

          by Anonymous Coward
          I am a physicist (student), but I've never been awesome at astrophysics, so grain of salt with all of this. You raise a bunch of good questions. So first: How do we know how far away Betelgeuse is? Per Wikipedia, estimates of its distance have varied widely over the last hundred years, from ~100ly to ~1000ly, with the current one being ~640ly. We guess stars' distance with a combination of parallax (only good if they're close or really big--Betelgeuse is really big), apparent magnitude (how bright they seem
        • Re:Soon? (Score:4, Informative)

          by Teancum ( 67324 ) <robert_horning@@@netzero...net> on Saturday January 22, 2011 @07:16PM (#34968662) Homepage Journal

          How do we actually know that the wave/particle/whatever I see when I glance up at Betelguese is about 600 years old. It seems to me that we would need to know a few things first, before we could calculate that:

          How we know the distance to Betelguese is due to Stellar Parallax [wikipedia.org] and other stellar distance measurement systems that use the parallax as a baseline. This is a system of measurement that is roughly the same what is used for surveying land using a compass and a transit, but applied to astronomical object.

          The point is not that the light is so old but that the star is so far away that based upon our understanding of physics that it would take about 600 years (give or take some.... the number isn't exact) for that light to reach the Earth. Quite literally, Betelguese is "600 light years" or the distance that light takes 600 years to travel at 300,000 km/second before it gets to the Earth. If you prefer to use kilometers, miles, or furlongs for measurement I can do the unit conversion but when dealing with those kind of distances it is much more convenient to stick with either parsecs or lightyears as a distance measurement.

          BTW, Betelguese is actually a "close" star in a broad sense, considering that the nearest stars to the Earth besides the Sun are about 4-5 light years away. It is still far enough away that even stellar parallax is not really working well and needs other ways to measure the distance, but "roughly 600 light years" is a good approximation. The main Wikipedia article [wikipedia.org] goes into more detail specific to this star.

          As for the other factors you are putting into there, the main thing is to point out the Einstein described that the speed of light is constant in all directions from all points of view. In terms of getting into the esoteric philosophical minutiae, you can plow yourself into metaphysics if you want to that is to me more like contemplating the existence of your belly button and what implication it might have if it is missing from your abdomen. Compared to the speed of light and the uncertainty of the measurement of the distance to this star, worrying about minor tweaks that could distort the distance measurement in this fashion is irrational and not worth the effort of refuting or even acknowledging.

          • I completely agree from a practical point of view. I actually wasn't trying to challenge the distance to Betelguese. This just seemed a good threat to bring up all the other questions in my original post, which was more about getting answers regarding relativity and the whether the speed of light is constant in expanding space-time.

            Thank you though for your info on Betelguese, it's a facinating star.

            I'm not really contemplating metaphysics, just trying to understand better 20th century physics. I shou
        • Re:Soon? (Score:5, Interesting)

          by Ruie ( 30480 ) on Saturday January 22, 2011 @07:54PM (#34968976) Homepage
          All good questions and guesses ! You should go get a Physics Ph.D., it is much fun !

          After the Big Bang occurred the matter was very very hot. So it looked basically like fire. But since entire universe was "on fire" and light has a finite propagation speed we can still see light just reaching us now from very far away places in the universe - Cosmic Microwave Background.

          It has many interesting properties. First, as you point out you can measure our speed relative to it. Secondly, it has a very long wavelength which is due to expansion of the universe - the places farther away are moving away from us.

          The expansion of the universe is actually very very small even on the scales of a solar system or galaxy and starts to matter on the intergalactic scales. It is characterized by Hubble constant [wikipedia.org]= 70 (km/s)/Mpc - for each million parsecs the speed goes up by 70 km/s. For comparison, Earth's orbital speed is 30 km/s and the size of the entire Milky Way (our galaxy) is only 30 thousand parsecs.

          Yes, there is a time dilation effect.

          Btw, speaking of time dilation effect, the scientists at NIST has recently built an atomic clock based on a single Aluminum atom [nist.gov] that is so accurate that they can see time dilation from Earth gravitational field. They measured the rate of their clock, than raised the setup and measured a faster rate - clocks slow down in stronger gravitational field and Earth field decreases by a small amount as you get further away from Earth.

    • by ghjm ( 8918 )

      Not in our reference frame.

  • by tverbeek ( 457094 ) on Saturday January 22, 2011 @03:19PM (#34967064) Homepage

    Just say its name three times and it'll all be under control.

  • We do? (Score:3, Insightful)

    by Anonymous Coward on Saturday January 22, 2011 @03:30PM (#34967164)

    As geeks, we can only hope the core of Betelgeuse undergoes catastrophic failure in our lifetime.

    I dunno. Betelgeuse staying the way it is suits me pretty good. 1). Orion is the most recognizable constellation there is. It's supposed to be a man with outstretched arms, and well, it looks like one -- with his belt, and the 4 brightest stars. Yeah, they're his shoulders and knees, but so what 2). Betelgeuse is a bight star, and it's noticeably red. So it's a good example of star colors. Right next to Aldebaran, Antares, and Sirius, nearby and also red and blue (blue-white) 3). If it blows tomorrow, The Hitchhikers Guide to the Galaxy will soon be confusing. Well, more so. And that's a great geek book. Basically, the only people left out seriously will be kids. But seriously, Betelgeuse, is an important tool for teaching children. Not like there's much we can do about it.

    • 1. I always see it as a Christmas present with a really tight bow around the middle, so meh.
      2. Algol is fairly bright, and very noticeably red, so we have a spare, plus the ones you point out.
      3. The Hitchiker's guide is a classic, ergo there will soon be an annotated edition if there isn't one already. We can put in a footnote about Betelgeuse.
       

  • Insurance (Score:5, Funny)

    by chill ( 34294 ) on Saturday January 22, 2011 @03:31PM (#34967168) Journal

    The question is, can I make money selling Betelgeuse supernova insurance to the general public?

    • The question is, can I make money selling Betelgeuse supernova insurance to the general public?

      There is no doubt in my mind you could pull it off.

    • by arivanov ( 12034 )

      Fast Tony? Is that you?

      We all know you will sell your mother for a grape...

    • Any question based around the notion of selling a worthless item to the general public almost invariably can be answered "Yes".

  • Will we be able to find his home planet now that Betelgeuse will turn supernova?

  • Party? (Score:5, Funny)

    by gregor-e ( 136142 ) on Saturday January 22, 2011 @03:43PM (#34967244) Homepage
    Driving home one evening, someone said we should hold a party for the death of Betelgeuse, and invite Michael Keaton. My girlfriend responded "Why? Because he's a dying star too?"
  • Come 22 December 2012 there will come another Great Disappointment [wikipedia.org].

    Falcon

    • by khallow ( 566160 )
      I think we're still in the Great Disappointment of Y2K. When the Y2K bug and other stuff didn't end the world, that left a lot of people pining for the next big end of the world. 2012 was the same sort of deal too, a calendar roll-date.
  • how long does it take after it blows for us to see it?

    • That depends on how far away Betelgeuse is, and we do not know that very well. The best estimate is about 640 light years, with an uncertainty of about 145 light years. This means that it would take the light from the explosion about 640 years to reach us. The first sign that we will get, however, will be a dramatic increase in the number of neutrinos seen at neutrino detectors. This is because supernova generate neutrinos during the initial collapse of the core of the star. The light, however, is not

  • It's mass calculations and core composition is as stated, it'd be a bitch if it threw a fit and sent out a sweeping gamma burst (think of a lighthouse but with a gamma beam a trillion times more intense than anything yet experienced) it might have lasted only for a year or so as the core of the resulting neutron star stabilized.

    2012 anyone?

    • Re:Let's hope that.. (Score:5, Informative)

      by mrsquid0 ( 1335303 ) on Saturday January 22, 2011 @06:14PM (#34968266) Homepage

      It is extremely unlikely that Betelgeuse will produce a gamma-ray burst. The current thinking is that supernovae only produce gamma-ray bursts in stars that have been stripped of their hydrogen envelopes. Betelgeuse still has most of its hydrogen, and there is not enough time to lose it before the supernova is likely to happen. Even if Betelgeuse does produce a gamma-ray burst the bursts occur along the rotation axis of the star, and Betelgeuse's rotation axis is not pointed towards us. Fortunately, we do not have to worry about a gamma-ray burst from Betelgeuse, because it is close enough that such a burst would be rather nasty for us.

  • I assume it's way past the size limit for creating a black hole when it goes supernova. Would it be the closest black hole to us?
    • I'm not up on this research, but I think it's a little unclear whether Betelgeuse will turn into a black hole. It all depends on how much mass is left behind after it blows off most of its mass during the supernova explosion. To say this is a difficult computational problem is putting it mildly.

      For comparison, the Cygnus X-1 black hole may have come from a star that was originally 40 solar masses [wikipedia.org] in size, while the Crab Nebula's star may have been about 9-11 solar masses [wikipedia.org]. Betelgeuse is about 19 solar mas [wikipedia.org]

  • Even if it does explode with the full brightness of our sun, it won't look anything like those scenes from Tatooine. Instead of having all that light spread over a disk as wide as our sun, it will all be concentrated from what appears to us as a single point. Instead of looking like another sun, it will look more like an extremely intense electric arc. It will be even more damaging to the eye to look at it, compared to looking at the sun, because more energy is concentrated into a single point instead of

  • Insensitive (Score:4, Funny)

    by shiftless ( 410350 ) on Saturday January 22, 2011 @07:26PM (#34968744)

    As geeks, we can only hope the core of Betelgeuse undergoes catastrophic failure in our lifetime.

    My home plant orbits Betelgeuse, you insensitive clod!

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