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Astronomers Awaiting 1a Supernova 204 204

Aryabhata writes to tell us BBC News is reporting that astronomers have sighted a star on the brink of a "1a" supernova. This opportunity presents the first chance astronomers have ever had to view a supernova of this magnitude up close. From the article: "They are so rare that the last one known in our galaxy was seen in 1572 by the great Danish astronomer Tycho Brahe, who first coined the term nova, for "new star", not realizing he was in fact witnessing the violent end of an unknown star. It has long been believed that type 1a supernovae are the death throes of a white dwarf star. But all modern ones have been so distant that it has not been possible to see what had been there beforehand."
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Astronomers Awaiting 1a Supernova

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  • How long?!? (Score:3, Interesting)

    by TJ_Phazerhacki (520002) on Sunday July 23, 2006 @03:56PM (#15766664) Journal
    This seems interesting only in the way that a man shouting about the end of the world downtown is. The timeframe involved isn't really anything to get excited about...
  • by 0racle (667029) on Sunday July 23, 2006 @03:56PM (#15766665)
    Any decade now.
  • That's nice (Score:5, Funny)

    by guardiangod (880192) on Sunday July 23, 2006 @03:58PM (#15766666)
    /. Headline: Astronomers Awaiting 1a Supernova

    From TFA:
    But soon, RS Oph could pass the tipping point - the nuclear flame will detonate from deep inside the star and blow it apart. How soon is not clear.

    "It could be tomorrow, but most likely it'll be 1,000, 10,000, 100,000 years from now," says Jeno Sokoloski.

    Wow that's some long life astronomers. I wonder if they will be around to see DNF getting release.

    Stupid headline.

  • by antifoidulus (807088) on Sunday July 23, 2006 @04:04PM (#15766675) Homepage Journal
    version 1a? They aren't even in beta yet!
  • Rho Casspiopiae (Score:5, Informative)

    by 9x320 (987156) on Sunday July 23, 2006 @04:06PM (#15766679)
    Rho Casspioiae [astrosociety.org] is supposedly near the brink of explosion, too, and aside from that, I remember hearing about some luminous supergiant or hypergiant expected to explode in the same constellation, Casspioia.

    Coincidentally, two other supernovas have ocurred in that area, one of which was the one Tycho Brahe saw. Keep an eye on the hypergiants (see: Wikipedia's explanation of how stars are classified [wikipedia.org])
    • Re:Rho Casspiopiae (Score:5, Informative)

      by SetupWeasel (54062) on Sunday July 23, 2006 @04:54PM (#15766784) Homepage
      Giant stars do not produce type 1a supernovae. Type 1a SN are believed to be caused by a binary system of a giant star and a white dwarf. When the one star becomes a giant, the atmosphere can be so large that it fills its gravity well and spills material onto the white dwarf. The white dwarf, which would never be massive enough to become a supernova on its own, gains the mass from its partner at a trickle until it reaches the mass necessary for it to collapse.

      Because type 1a SN are believed to occur under nearly identical circumstances, they are considered especially important in astronomy. Astronomers believe that they can be used as what they call "standard candles." A "standard candle" is a light source of known brightness. Standard candles are important, because astronomers can directly determine the distance of these sources. Certain stars already act as standard candles, but stars can only be resolved at a certain distance. A type 1a SN can be seen at such a large distance that astronomers believe they can more accurately determine cosmoloigical properties if they can determine exactly how bright one is, and how it may fluctuate under different circumstances.

      Other SN are interesting, but a Type 1a SN in our galaxy might tell us a lot about the entire universe indirectly.
      • Sorry there, I was thinking of a type 1a star causing a supernova, not a type 1a supernova being caused by a binary system.
      • IANAA (I am not an astronomer), but let me guess. When you have a binary system you can guess the masses of the stars from the orbital period, and you also have an estimate of the distance between them. If the larger star is spilling material on the smaller one it's because it's exceeding its Roche radius, so you also have an estimate of its size. Is that it, or not even close?
        • by T.Hobbes (101603) on Sunday July 23, 2006 @10:31PM (#15767623)
          You are right that you can estimate stellar masses in binary systems by observing the system's orbital period. However, that is only useful for binary systems that are close enough for our telescopes to resolve (visually) the space between them. There are other, non-viusal methods that are used, but you basically have a limit on how far away a binary system can be for it to be observed in this way.

          The utility of type 1a supernovae is that they are all produced by white dwarf stars exploding. White dwarfs are roughly earth-sized stellar cores that have no thermonuclear reactions going on inisde - they are the remnants of stars between about 1 and 5 solar masses after the outer layers have been blown off.

          The imporant point is that the gravity of the stellar core's mass is not counteracted up by the pressure of the thermonuclear reactions inside. Rather, something called degenerate electron pressure holds the white dwarf up and prevents it from collapsing. Degenerate electron pressure can only counteract gravity for masses up to 1.4 solar masses, meaning that any white dwarf that somehow grows to a mass greater than 1.4 solar masses (usually by grabbing mass from a companion star), it will collapse. The collapse catastrophically increases the pressure inside the white dwarf, re-igniting nuclear fusion, and produces a sudden violent explosion.

          Because white dwarfs are all of the same mass when they explode - 1.4 solar masses (the Chandrasekhar (sp?) limit - they are all of roughly the same brightness (>10^9 times as bright as the Sun). Because of this, one only has to see a type 1a supernova to deduce from the apparent brightness the distance from earth to the explosion. If a type 1a supernova occurs inside a cluster of stars, it conveniently tells us the distance from here to that cluster of stars. Because the distances over which supernova can be observed is orders of magnitude greater than most other stellar phenomena, the are essential in determining distances to faraway objects (from 1 to 1000 megaparsecs away (1 parsec = ~3.2 light years)). Distances to other galaxies are determined this way.

          They type of supernova being observed can be determined by the specatra of light coming from it. I can't recall the distinguishing characterisitics of type 1a supernova, but suffice it to say they can be distinguished from other types of supernova.
      • Re:Rho Casspiopiae (Score:3, Informative)

        by niktemadur (793971)
        Astronomers believe that they can be used as what they call "standard candles."

        Something to add here, in regards to cosmic cartography:

        Parallax can only be used to measure distances within a radius of a couple of dozen light years beyond Earth. This technique gave us the Herzprung-Russell diagram, which is basically a profile of all known type of stars in the main sequence, various combinations of age, size, color and temperature.
        Cepheid variables allow us to measure distances outwards to a
    • more likely you're thinking of Eta Carinae [wikipedia.org] which is also expected to "go any time" (in stellar timescales) and has been playing up recently
  • by Anonymous Coward on Sunday July 23, 2006 @04:19PM (#15766701)
    I took Computer Science as a Humanities subject in college. My girlfriend took it through science. The CS courses feature the same modules, but she was able to take Astrophysics, while I took English. We both consider outselves to have a scientific leaning, though I wouldn't consider myself a "scientist" and she would.

    She read the /. blurb and was bouncing (literally!) with excitement, saying "they are reporting it now, so most likely it will be in ten, twenty years - within reasonable research time". I read it and my initial thought was that these reports are being made by science types. That means that this supernova will most likely occur in about 10,000 years, but that some scientist, in a lab somewhere, has just had the bright idea of pushing his research into the media spotlight, where it should (he hopes) be interesting enough to secure him a few more years worth of funding.

    From the article: "How soon is not clear [but] ...astronomers will be studying the star closely, to watch its every step towards destruction, and hoping to understand the full details of one of the heaven's great mysteries". *sigh*

    My girlfriend's lack of cynicism aside, this is one of my major problems with the science community. So much is driven by a desperate need to secure funding, that science "news", most of the time, is either hypothetical, theoretical, or so far in the future that it makes no difference to the present. In these cases, when a person finds out that no actual advance has been made, he feels both disappointed and betrayed.

    I am fed up with reading...

    "Newsflash: No physical reason humans cant live to be 300, once the technology arrives!" *

    or

    "Newsflash: the universe *might* be made up of string!" *

    or

    "Newsflash: in 100 billion years, this star will explode!" *

    etc, when the invisible postscript to every story is:

    * Now that I have your attention, please give me some more funding!
  • Tycho Brahe (Score:2, Funny)

    by Fishstick (150821)
    Isn't that the guy from penny arcade [penny-arcade.com] ?

    *yeah, I know
  • "Soon" ... (Score:5, Insightful)

    by kcbrown (7426) <slashdot@sysexperts.com> on Sunday July 23, 2006 @04:40PM (#15766746)

    "Space is big. Really big. You just won't believe how vastly hugely mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." -- the Hitchhiker's Guide to the Galaxy.

    Not only are the distances vast, the times are vast too. Stars live for billions of years. One year in the lifespan of a human is roughly comparable to perhaps 70 million years in the lifespan of a star.

    So when someone says "soon" in reference to a prediction of when some stellar event is going to occur, it's likely you'll have to scale up the term by roughly the same amount. "Soon" to a human generally means within/around a day or so, so scaled up to stellar times, that would be within/around 200,000 years.

    I expect that by the time this supernova happens, humans will either be unbelievably technologically advanced, or they'll be extinct.

    • I expect that by the time this supernova happens, humans will either be unbelievably technologically advanced, or they'll be extinct.


      So if something/someone doesn't kill us all in the meantime, will we be advanced enough to use this as a power source?
      • Re:"Soon" ... (Score:3, Insightful)

        by topham (32406)

        Based on the current trends it will provide just enough power for one person to travel to the corner store.

    • Re:"Soon" ... (Score:2, Informative)

      by Anonymous Coward
      So when someone says "soon" in reference to a prediction of when some stellar event is going to occur, it's likely you'll have to scale up the term by roughly the same amount. "Soon" to a human generally means within/around a day or so, so scaled up to stellar times, that would be within/around 200,000 years.

      That depends on the star though. Giant stars for example are quite short-lived (millions of years instead of billions), and the last step in the fusing process where the whole core of a star gets conver
    • This is why it annoys me to hear people bleating about wanting affordable space travel within their lifetime "so that we can preserve the human race".
    • Not only are the distances vast, the times are vast too.

      There is actually another star about to go nova that is only half the distance of RS Ophiuchi. Nobody talks about it, though, because no astronomer wants to waste time on a half-vast star.
  • by Baloo Ursidae (29355) <dead@address.com> on Sunday July 23, 2006 @04:52PM (#15766773) Journal
    I've never seen a star go supernova before. But if it's anything like my old Chevy Nova, it'll light up the night sky!
  • by Mantrid42 (972953) on Sunday July 23, 2006 @05:05PM (#15766807)
    http://en.wikipedia.org/wiki/Supernova#Impact_of_s upernovae_on_Earth [wikipedia.org]
    Speculation as to the effects of a nearby supernova on Earth often focuses on large stars, such as Betelgeuse, a red supergiant 427 light years from Earth which is a type II supernova candidate. Several prominent stars within a few hundred light years from the Sun are candidates for becoming supernovae in as little as 1000 years. Though spectacular, these "predictable" supernovae are thought to have little potential to affect Earth. Type Ia supernovae, though, are thought to be potentially the most dangerous if they occur close enough to the Earth. Because Type Ia supernovae arise from dim, common white dwarf stars, it is likely that a supernova that could affect the Earth will occur unpredictably and take place in a star system that is not well studied. One theory suggests that a Type Ia supernova would have to be closer than 1000 parsecs (3300 light years) to affect the Earth.

    Shit.

    • If you look at the next paragraph, things don't look so bleak.

      Recent estimates predict that a Type II supernova would have to be closer than 8 parsecs (26 light years) to destroy half of the Earth's protective ozone layer.[2] Such estimates are mostly concerned with atmospheric modelling and considered only the known radiation flux from SN 1987A, a Type II supernova in the Large Magellanic Cloud. Estimates of the rate of supernova occurrence within 10 parsecs of the Earth vary from once every 100 million y

    • At least you have 1,950 years to get out of the neighbourhood.
    • by KylePetty (990568) on Sunday July 23, 2006 @06:15PM (#15766983)
      Before everyone goes nuts saying our goose is cooked. It appears that not all sources agree as to the distance of this star. While some sources claim the star is 1,950 light years away, others claim it is as much as 5,000 light years away. http://www.sciencenews.org/articles/20060722/fob8. asp [sciencenews.org] On referring to RS Ophiuchi, ScienceNews states: "That finding could have two interpretations, suggests the report's coauthor Richard Barry of NASA's Goddard Space Flight Center in Greenbelt, Md. If the star system resides at about 5,000 light-years from Earth, then the emissions reflect a mysterious, dense reservoir of material surrounding the two stars. If the system lies at only about one-third that distance, then the emission may for the first time be revealing a short-lived epoch during which the white dwarf, soon after its outburst, becomes as bloated as its red giant partner." Sites like Space.com claim it is 5,000 light years away, while Wiki has it pegged at 1,950. Meanwhile, the Harvard Gazette reports that: "When do scientists think the Ophiuchi supernova will rock the universe? Of course, no one knows enough about what goes on out there to say. But the best guess is it will take thousands of years for the final bit of gas to accumulate and blow the white dwarf away. Meanwhile, these reports should stimulate many more astronomers to focus their attention on the constellation Ophiuchi." So... I think it's a bit premature to claim we are doomed.
      • Before everyone goes nuts saying our goose is cooked. It appears that not all sources agree as to the distance of this star.

        On the plus side, when it goes boom, since its type 1a we wil know _exactly_ how far away it is, and whether we're or not we're screwed.
    • But if you check the footnote, that "One theory" is a back of the envelope calculation and some guesses combined together to say it would provide 1000x as much gamma radiation on the Earth as a solar flare...
    • Aim matters (Score:2, Interesting)

      by Tablizer (95088)
      I believe the danger depends on where the star is "aimed". Magnetic fields focus the energy at the poles so that much of the energy is directed in narrow beams of radiation. If the star is fairly near and the "pole beam" is aimed at Earth, we may be fried. Some describe it as Cosmic Russian Roulette.
  • On the timescales they're discussing the 1572 sighting was "last year"!
  • Not to rain on anybodies parade, but if that supernova sends a gamma ray burst in our direction. We can kiss our asses goodby....

    Have a nice Sunday!
    • by istartedi (132515) on Sunday July 23, 2006 @06:15PM (#15766986) Journal

      IANAExpertOnThisCrap, but... if the burst lasts less than 12 hours, at least a north-south slice of the planet would be spared. If it's just a few minutes, only half the planet would be "fried", and if the Pacific Ocean happens to be facing it, then it's only bad for the relatively small island population, but if Eurasia is facing it, that's gonna be really really bad.

      Of course, that's based on the event being near the plane of the ecliptic. If the event was near a pole, then one of either the North or South hemispheres is fried, the other is spared.

      I'm also assuming that the gamma rays aren't powerful enough to turn surface matter into radioactive isotopes that pollute the atmosphere and ocean, or to do that to the atmosphere itself. In that case, it's more proper to say that the Earth is poisoned, not fried.

      • by klaun (236494) on Sunday July 23, 2006 @08:42PM (#15767379)
        I'm also assuming that the gamma rays aren't powerful enough to turn surface matter into radioactive isotopes that pollute the atmosphere and ocean, or to do that to the atmosphere itself. In that case, it's more proper to say that the Earth is poisoned, not fried.

        I think your confusing types of radiation here. Gamma rays are electromagnetic radiation and will not create radioactive isotopes no matter how intense they are. Generally, what they are going to do is ionize atoms and heat things up. Damage to biologicals from Gamma rays is via ionization and heat effects.

        If there were a very intense neutron burst, that could potentially "activate" some materials, i.e. transmute them into a radioacive isotopes. However, neutron burst are not going to be something we have to worry about at this distance from the event.

      • If a Gamma Burst from a supernova hits us it will not matter WHICH side of the planet get's it. First the Atmosphere would be toast then the planet would cook to a sinder.

        http://en.wikipedia.org/wiki/Gamma_ray_burst#Mass_ extinction_on_Earth [wikipedia.org]
    • Not to rain on anybodies parade, but if that supernova sends a gamma ray burst in our direction. We can kiss our asses goodby.... ...and get new big, mean, and green ones.
    • Not to rain on anybodies parade, but if that supernova sends a gamma ray burst in our direction. We can kiss our asses goodby....

      It won't make gasoline more expensive, will it?

      Although I'm sure technology will have advanced by then to let me use gamma rays to run my Hummer.
    • Not to rain on anybodies parade, but if that supernova sends a gamma ray burst in our direction. We can kiss our asses goodby....

      If we are all going to die then why did we invest in swift

      http://www.nasa.gov/mission_pages/swift/main/index .html [nasa.gov]
    • ...if that supernova sends a gamma ray burst in our direction, we can kiss our asses goodbye...

      Which begs the all-important question: Has the correlation between Type 1a Supernova and Gamma Ray Bursts been confirmed beyond a shadow of a doubt?

      The way I understand the theory, which is not yet engraved in stone, if either of this star's magnetic poles are pointing towards Earth, we're gonna get zapped. However, if we're facing the star's equator, or anywhere but the poles for that matter, we're home free.
    • Not to rain on anybodies parade, but if that supernova sends a gamma ray burst in our direction. We can kiss our asses goodby....

      Only if you moon it. [rimshot]
  • "May the best sentience win."

    (Psst: obscure nerdy reference.)

  • "It could be tomorrow, but most likely it'll be 1,000, 10,000, 100,000 years from now," says Jeno Sokoloski.

    I'll never complain about lag on IRC again!
  • tycho (Score:3, Funny)

    by minus_273 (174041) <aaaaa&SPAM,yahoo,com> on Sunday July 23, 2006 @05:48PM (#15766901) Journal
    "They are so rare that the last one known in our galaxy was seen in 1572 by the great Danish astronomer Tycho Brahe"

    from what i heard, Gabe was pretty pissed about not being invited to it. Apparently he also looked at his neighbor with a telescope ans stole a haribrush she thre out as well.
  • Range of lethality (Score:4, Interesting)

    by Short Circuit (52384) * <mikemol@gmail.com> on Sunday July 23, 2006 @07:25PM (#15767185) Homepage Journal
    I'm curious. At what range would a Type 1a supernova be lethal to life on Earth?

    As far as the size of the galaxy is concerned, 1,950 light-years is essentially in our back-yard. Keeping with scale, are we talking about a firecracker or a stick of dynamite?
    • by zepol (697768) on Sunday July 23, 2006 @08:15PM (#15767308)

      While this doesn't directly answer your question, you might find the following interesting. Steven Dutch, a professor at the University of Wisconsin at Green Bay has estimated what would happen if the sun were to go supernova [nagt.org]. Some highlights: the radiation flux on the daylight side of the earth would be the same as if our entire nuclear arsenal were to go off once per second at a distance of one kilometer. The reflected light from the full moon would be 10,000 times brighter than the sun; Venus would shine six times as intensely as the normal sun. The earth vaporize in a matter of days.

      By the way, the sun will never become a supernova. The calculations are illustrative only.

    • by KwKSilver (857599) on Monday July 24, 2006 @12:02AM (#15767844)
      According to Wikipedia, the "serious effects" range for Type Ia supernovae is about 1000 parsecs or 3300 light years. If 1950 light years is the correct distance to RS Ophiuchi, we are in the danger zone. Evidently from above posts & links Rho Cassiopeiae is also on the verge, but it's 8000 to 10,000 light years distant and a "mere" type II supernova candiate, anyway. Rho Cassiopeiae = fireworks display. RS Ophiuchi = hand grenade at least and maybe a 2000 lb bunker-buster. Lots of calculations here. [rit.edu]
    • According to the link I provided above, a Type 1a supernova would have a gamma ray flux equivalent to 1000 solar flares at 1000 parsecs (10 is the max on any given day!). My recollection of how inverse square works is fuzzy, but I think at our distance we get 1000/(1950/3300)^2 or a flux greater than 2850 solar flares. I dunno, sounds bad.
  • by Starker_Kull (896770) on Sunday July 23, 2006 @08:01PM (#15767269)
    We've had supernovas recorded throughout human history; Wikipedia lists ones occuring in our galaxy (meaning, close enough to be easily observable) in 1006, 1054, 1181, 1572, 1604, and I remember from other sources that several were observed during Roman times. It seems that we've been "unlucky" in that ever since we've started to have precision astronomical instruments, we haven't had one go off in our galaxy. It would be really interesting if we would finally get one in modern times - and since they seem to go off about every 200 years or so, it doesn't seem that unlikely we might get one in our lifetimes. So here's to a little optimism!

    • The supernova that made the Cas A remnant is estimated at 1665AD or so. There was so much dust in the way that no one even saw it with the possible exception of the astronomer Flamsteed who recorded what he thought was a normal star there but when we look there today there's no star of the brightness Flamsteed saw. Dust can really dim a supernova so much that we don't see it, but since we're looking around with even neutrinos and radio that dust doesn't stop it'll be detected even if it's on the far side o
    • by niktemadur (793971) on Monday July 24, 2006 @01:26AM (#15767992)
      Wikipedia lists ones occuring in our galaxy in 1006, 1054, 1181, 1572, 1604, and I remember from other sources that several were observed during Roman times.

      Isn't that typical. Before the telescope, there was a frickin' smorgasboard of supernovae at close range, then no sooner does man invent the telescope and the party's over, which draws me to the conclusion: I blame this supernovae drought on Galileo.
  • So basically, a star that MIGHT be reaching the THEORETICAL size limit of a white dwarf that actually may have gone Nova over a THOUSAND YEARS AGO, MIGHT, MAYBE, IF WE'RE LUCKY, be visiable from earth sometime between TOMORROW AND ONE HUNDRED THOUSAND YEARS FROM NOW.

    Wow. What incredible science. Did NewScientist buy the BBC over the weekend?
  • view a supernova of this magnitude up close.

    Not too close, I hope.

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