Astronomers spot ticking supernova time bomb

By Phil Plait | November 17, 2009 10:09 am

What does a star on the edge of death look like? Perhaps not what you think:

v445puppis

This series of images [as usual, click to embiggen], from the European Southern Observatory’s Very Large Telescope, will take some ‘splainin. Hang on.

A supernova — an exploding star — is among the brightest single objects in the known Universe. A supernova can release as much energy in a single second as the Sun will in a thousand years.

Most people think of supernovae as massive stars exploding at the end of their lives, but there is another kind. When the Sun finally dies in a few billion more years, it will shed most of the material making up its outer layers, revealing the white-hot, dense core. This superhot ball will have half the mass of the Sun in it, but only be the size of the Earth. We call such a thing a white dwarf.

If a white dwarf orbits a normal star like the Sun, it can draw material off. This matter piles up on the surface and can eventually detonate like a stellar thermonuclear bomb. We call these Type Ia supernovae.

The thing is, massive stars are bright, so we can see them a long way off. We know of many stars in our galaxy that can blow that way (though all too far away to hurt us). But a Type Ia progenitor is faint, and hard to spot. Usually, the first notice we get of one is when it explodes, and we see the sudden and vast increase in light in a distant galaxy.

But astronomers have spotted a potential Type Ia supernova in our own galaxy, a ticking time bomb about 25,000 light years away. Called V445 Puppis, in November 2000 it underwent an explosive event: not a supernova, but a regular nova, the detonation of small (in cosmic terms) amount of material. Still, it ejected a lot of matter — several times the mass of the entire Earth — at very high speed, about 24 million kilometers per hour (14 million mph). That would reach from the Earth to the Moon in one minute flat. Over the course of several years, astronomers have taken images of the expanding debris, and the change — seen in the picture above — is dramatic, lovely, and terrifying.

The debris did not expand spherically because the two stars are in a tight orbit, circling each other rapidly. The matter drawn off the normal star forms a thick disk around the white dwarf. When the material on the surface exploded, it couldn’t go through the disk, so it went up and down, above and below the disk. Over time it forms what’s called a bipolar structure, because it comes out of the poles of the star. We see lots of similar bipolar objects, but not usually in a system that’s about to go bye-bye.

Tellingly, there is no detectable hydrogen in the system. The surface of the white dwarf appears to be mostly helium, and the normal star looks to be dumping only helium on the white dwarf. Type Ia supernovae are hydrogen poor, even lacking it completely, so that fits.

Also, the mass of the white dwarf in V445 Puppis is on the thin hairy edge of the maximum it can be before it blows. When a white dwarf reaches 1.4 times the mass of the Sun, it goes kablooie (I had to calculate this as a homework problem in grad school). V445′s mass? 1.35 times that of the Sun.

Yikes.

So when will the system go off? Hard to say. It may not be for thousands millions of years. At that distance, it will be very bright in the sky, brighter than Venus. It won’t hurt us; it’s way too far away to to do that. But a nearby supernova of this type would be a huge boon to astronomy! It’s this flavor of supernova we use to measure the expansion of the Universe (since they are so bright they can be seen very far away, and tend to blow up with the same brightness every time).

It’s a little funny to think that the death of a star so many quadrillions of kilometers away can actually be a benefit to us. But remember, the calcium in our bones and iron in our blood came from supernovae like the one V445 Puppis will eventually become, so not only do we learn more about the Universe from them, we owe our very existence to them as well.

Comments (66)

  1. Dan I.

    Man how awesome would it be for this thing to blow up in our lifetimes. Talk about freaking people out though.

    Hey, maybe it’ll blow up on Dec. 21 2012 and REALLY freak out the Doomsayers.

  2. Any calculations out there on the rate of accumulation of mass on the white dwarf? Granted, we’re talking solar masses, so it’s not like that amount of material is built up in a matter of days. I really would love for this to happen soon so we can learn more stuff!

    How long would a Type Ia be luminous in our sky? Aren’t these rather short lived in that regard?

  3. DaveS

    So if one of the lobes was pointed right at us, would it fry us when it explodes? Or does it explode more spherically?

    (Reading DFTS right now, just finished the supernova section, into the black hole section, so this is timely for me.)

  4. Dan I beat me to the 2012 comment.

    Speaking of 2012, and OT, Discovery Channel (I think…might’ve been Sci-Fi) has been airing 2012: Startling New Secrets, recently, featuring the lovely Richard Hoagland. Phil, have you seen it yet? I know you’ve already commented on the whole 2012 thing before, but I was wondering if you had thoughts on this newest iteration in the media.

  5. Ah yes, the Chandrasekhar limit!
    I hope it blows while the Hubble is watching & taking spectra all the while!

  6. dcsohl

    Type Ia supernovae reach a maximum absolute magnitude of -19.3, with very little variation (+/- 0.15). At 25,000 ly, that absolute maximum would appear, as Phil says, brighter than Venus. I get a maximum of apparent magnitude -4.88.

    In the first 30 days after maximum, Ia types fade by about 2.7 magnitudes, so that would make this one around -2.2. Still brighter than Sirius.

    From the 30 day point, the rate of fading slows. It would be almost 90 days before it faded by 5 magnitudes, to around magnitude 0. Still a very bright star.

    And these supernovae don’t just pop into existence. There is a ramp-up in brightness, of almost 30 days from when they are typically first observed until maximum brightness.

    So, in summary, this one would be visible for a long time. It’d be immediately apparent to the untrained eye for about 4 months, and still observable for a number of months past that.

    Info gleaned from here (25th page of the PDF, labelled page 551) and here.

  7. Thank you dscohl! :D Exactly what I was looking for.

  8. Bill Nettles

    Dan I says “Hey, maybe it’ll blow up on Dec. 21 2012 and REALLY freak out the Doomsayers.”

    Dan, could it be that that IS what the Mayan calendar is really about? Woooooo…(Twilight Zone music) do do do do

    That would be supercool…er hot…a real blast…simply stellar!

  9. As a lobbyist for the Gloon Foundation, located in the Beta Zoondar cluster, a mere 2.5 lightyears from v445 Puppis, I would like to ask you all to kindly stop encouraging this sort of thing.

    Thank you.

  10. Dear Mr. kuhnigget,

    We regret to inform you that your world has been scheduled for demolition. You should have known, though, as the notice was clearly on display in the back of a filing cabinet in the subbasement of the clerk’s building for several millenia. It’s too late to whine about it now.

    Sincerely,
    Groflklork
    President, Supernovae-R-Us

  11. I calculate that ejection speed at just over 2% of c. Man, that’s fast!

  12. ND

    “It may not be for thousands of years, or even longer. ”

    grrr. I can’t wait that long! I want a Type Ia and I want it now!

  13. Brian

    What a cool thing to have in our sights. Apologies to the Beta Zoondarians. Still would love to see it blow.

  14. Steven

    So what happens to the other star in the pair? Do you get a chain reaction or does it just need to be directed to a good domestic abuse support service?

  15. If it is bipolar then perhaps it needs more lithium.

  16. Waaaaaaaaaaaaaaait a minute.

    Last I heard, the Chandrasekhar Limit wasn’t exactly 1.4 solar masses, it was more like 1.44 solar masses.

    So while 1.35 solar masses is PRETTY close, it’s not ZOMG-it’s-gonna-blow-any-second-now close.

  17. Gamercow

    I know this happened. Wanna know how? I drew a picture of it! http://antwrp.gsfc.nasa.gov/apod/ap091117.html

    Okay, so I didn’t draw that. Still, its interesting that Phil and APOD cover the same subject today.

  18. Clint Johnson

    Am I being a bit of a pedant in reminding all that this isn’t happening right now? Those pictures are from 25,000 years ago so if v445 Puppis went Ia supernovae 24,000 years ago then:

    A) We won’t see it for another thousand years.
    B) Poor Kuhnigget has been dead for 21,500 years.

    A moment of silence please.

    On a related note, I would suggest that the first task for any contemporary physics contradicting supra-luminal ships would be to jump out in a spherical pattern so as to make observations and give us advanced warning for any such large scale event that threatens out existence.

    Hmmm, I see a science fiction story in that… I’m off to the word processor.

  19. Jim

    From what I understand (correct me if I’m wrong, Phil) the mass limit for type Ia supernovae is a bit lower than regular core-collapse ones. So it’s closer than it seems.

  20. Yay, I was just reading about the Chandrasekhar limit today on APOD.

  21. When I read 24 million kilometers per hour, I didn’t think Earth-Moon, I thought of Sun-Earth transit time. By my calculations, if the Sun went Supernova like this, it would take just over 6 hours for the matter to reach the Earth. Of course, light goes faster than this so we’d see the supernova about 8 minutes after it happened. And then we’d have 6 hours to kiss our rears goodbye.

    Yes, I realize that before the Sun went supernova, it would expand and engulf the Earth (or at the very least fry us to a crisp). Still, this would make for an interesting disaster movie with poor science but fabulous special effects… You know, like pretty much any Hollywood disaster movie! ;-) I can see the tagline now: “What would you do if you had 6 hours to live?”

  22. MadScientist

    I want to see a star go kablooie! and put a nice bright spot in the sky visible to the unaided eye.

    As for Helios, that star is doomed to become a Red Giant, isn’t it?

  23. DrFlimmer

    Damn, I should have known this earlier.

    Some of those frakkin’ EU-guys showed this star as evidence for a current powering a star. I guessed that it would be outflows and that something is blocking our view in the middle. But that it is a possible Type Ia-candidate would have been much more interesting and much more compelling.

    This is sad. Such a glorious piece of astronomy and science, and I think of the EU-crap. Sorry, guys.

    Great article, Phil, thanks a lot :)

  24. Steve in Dublin

    Coincidentally, I just finished reading the corresponding chapter of Death From the Skies! a few hours ago. Great timing!

  25. Azam

    An amateurish question but I hope someone would be kind enough to embiggen my knowledge. Exactly how does the explosion of a typeIa supernova allow us to measure the expansion of the Universe?

  26. @ ND:

    grrr. I can’t wait that long! I want a Type Ia and I want it now!

    That can be arranged. Buwah ha ha ha haaaa!

    @ Todd:

    Do I have time for some peanuts?

  27. Stevie

    Well, Perhaps, It’s a ” New Star ” , much like the star that signaled the coming of Jesus … Perhaps , it will signal the Second coming that everyone is yapping so much about . I think it will signify the increase in sales of small , backyard telescopes ….

  28. How does a star close to exploding from old age look like (hourglass) a star that is just forming?

  29. Evil Eye

    What’s in YOUR universe? ;)

    This would be SOOOOOOO cool.

  30. Why Big Snake it wouldn’t have something to do with pinching from magnetic fields and plasma would it?

  31. Gary Ansorge

    31.Shane:

    Actually, from what I’ve read recently, it’s the accretion disk that’s blocking our view AND preventing the exiting material from escaping thru the disk so it has to exit from the poles. Thus, hour glass shape.

    GAry 7

  32. @Gary
    Thanks. I’ve been trying to find out exactly what causes the hourglass shape and the magnetoplasmaelectricuniverse stuff kept coming up.

  33. Brian Too

    What are these hypernova I’ve been hearing about? Besides being bigger, how are they different from supernova?

  34. Matthew Ota

    I want to see a local nova go off in northern hemisphere skies, so I can see it with my own eyes.

  35. 22. TechyDad Says:
    I can see the tagline now: “What would you do if you had 6 hours to live?”

    Reminds me of one of the few ‘New’ Twilight Zone episodes I liked with Michael (Tremors 1-4) Gross, where he saw a sudden brightening of the Moon, and determined (incorrectly) the Sun had ‘gone nova’ and the Earth was being scorched as it moved into ‘sunrise’.

    The fact that we can’t (yet) determine the time when the star will ‘go boom’, also brings to mind the sequel to The Mote In God’s Eye (The Gripping Hand), where the ‘Moties’ accurately predict a stellar event (nova? star ‘igniting’? don’t recall exactly), but the Humans (an interstellar society) can’t.

    J/P=?

  36. nicknameNick

    @Azam

    All 1a supernova’s appear to produce very similar amounts of light, so if we identify one, we can measure how bright it appears to be from out point of view, and compare that to how bright it should be at its source, and trivially calculate the distance, probably using the inverse-square law for the relationship between signal strength and distance.

  37. StevoR

    Awesome post BA. Thanks. :-D

    @ 23. MadScientist Says:

    I want to see a star go kablooie! and put a nice bright spot in the sky visible to the unaided eye. As for Helios, that star is doomed to become a Red Giant, isn’t it?

    Me too – Eta Carinae, Betelgeux and Antares seem to be our best hopes for that but there may well be many obscure white dwarfs that could surprise us which would be uber-cool! 8)

    As for Helios (our Sun I presume you mean) yes – it’ll evolve into a sub-giant then an orange giant then a second ascent /AGB branch red giant then a Mira variable star then a planetary nebula then a white dwarf before slowly cooling & fading away as a crystallised black dwarf after hundreds of trillions of years.

    Something to look forward too – or not! ;-)

  38. StevoR

    @ 35. Matthew Ota Says:

    I want to see a local nova go off in northern hemisphere skies, so I can see it with my own eyes.

    Ah but I want one to go off in the southern* hemisphere skies so that *I* can! ;-)

    Hmm .. Shall we compromise and have a star near the celestial equator go BOOM! ;-)

    (Betelgeux is a possibility there.) If only we could arrange it! ;-)

    NB. I did read an SF novel ‘Starhammer’ by Christopher Rowley which featured a machine that could blow up stars like that – ah the fun I could have with that toy!

    34. Brian Too Says:

    What are these hypernova I’ve been hearing about? Besides being bigger, how are they different from supernova?

    They completely destroy their more massive progenitor stars not even leaving a neutron star or Black Hole behind and involve a slightly different mechanism – proton-antiproton the pair instability reaction.

    PS. See : http://en.wikipedia.org/wiki/Hypernova &
    http://en.wikipedia.org/wiki/Pair-instability_supernova

    @ 17. tracer Says:

    Waaaaaaaaaaaaaaait a minute.

    Last I heard, the Chandrasekhar Limit wasn’t exactly 1.4 solar masses, it was more like 1.44 solar masses. So while 1.35 solar masses is PRETTY close, it’s not ZOMG-it’s-gonna-blow-any-second-now close.

    Ah, but hang on again .. What are the error bars there? 1.44+/- ?? ;-)

  39. Astroquoter

    A possibly pertinent quote here :

    “…about 40 supernovae are exploding somewhere in the universe every second. However, light from most of these events won’t reach Earth for billions of years, if ever.”

    - Page 73, “Ask Astro” in ‘Astronomy’ magazine October 2008.

  40. Here is a chalenge for the LHC Super Collider, cCreate a Supernova. A small one please. For those not familiar with the LHC mini-blackhole generator, see http://en.wikipedia.org/wiki/SuperCollider

  41. JIm Deeson

    Boy I wouldnt want to be anywhere near that when it goes off!

    RT
    http://www.online-privacy.at.tc

  42. these are natural but in the coming time LHC will produce big bang and supernova artificial for getting clue of origin of universe.

  43. 1. Question. -the speed of light is constant. -Nothing can travel faster than the speed of light -

    How is it then possible that this star 25,000 light years away will blast light/matter at such a speed that it will reach earth in 1 minute.

    Am i missing something here?

  44. Allan

    Embiggen? Embiggen!

  45. Flying sardines

    @ 42. Lila Sovietskaya Says:

    Here is a chalenge for the LHC Super Collider, cCreate a Supernova. A small one please.

    I don’t think supernovae come in “small” – & I think you need a star before you can have a supernova too.

    So I somehow doubt that the LHC will be able to grant that particular request there! ;-)

  46. Nigel Depledge

    Dr Flimmer (24) said:

    Some of those frakkin’ EU-guys showed this star as evidence for a current powering a star. I guessed that it would be outflows and that something is blocking our view in the middle. But that it is a possible Type Ia-candidate would have been much more interesting and much more compelling.

    This is sad. Such a glorious piece of astronomy and science, and I think of the EU-crap. Sorry, guys.

    Hey, what’s your beef with the European Union anyway?

  47. Gary Ansorge

    39.Shane

    Ref your link: “There is a constrant stream of high-energy galactic and solar radiation interacting with the Earth’s upper atmosphere,” the report noted. “This interaction creates a cascade of secondary particles. Some of the secondary particles, in particular neutrons, can affect aircraft avionics systems.”

    I guess that means the electronics they use aren’t radiation hardened. I note they imply neutrons are secondary radiation, but from what I recall of my basic physics, energetic interactions between cosmic rays and the atmosphere should mainly produce charged particle secondaries, not neutrons.
    Ah well, I guess we can’t expect all avionics experts to also be grounded in physics.

    Gary 7

  48. DrFlimmer

    @ Nigel Depledge:

    With the European Union? Nothing. Thank god they finally signed the new treaty, so finally the EU can do politics, again.

    But EU in this case meant something different (as you might have guessed ;) ). It has the meaning of PU or PC. ;) (And no, the latter does not mean personal computer ;) ).

  49. ND

    @ kuhnigget

    “@ ND:
    grrr. I can’t wait that long! I want a Type Ia and I want it now!
    That can be arranged. Buwah ha ha ha haaaa!”

    You have a stargate lying around?

    Testing to see if blowing up a star using a stargate sounds like a great Mythbusters episode!

  50. i8taterz`

    What if we could capture the energy produced when that thing explodes. Imagine that. We would have the energy that the sun would produce in over 1000 years! Talk about being efficient. Not only would we have to stop depending on other countries for our energy. AND we could find a way to sell this energy and our economy would boom. Think about it :)

  51. Gary Ansorge

    47. ND

    Let’s see. Since a stargate only allows matter to flow one way, I suppose we could connect one star with another, then open the Gate and watch the flow build up,,,,oh, wait, we don’t have access to a Gate big enough for starships to pass,,,oh well, never mind.(Ok! So! There would be matter flow, but it would take about a billion years to get enough mass accumulation to trigger a nova).

    A better way might be to use a super particle accelerator to accelerate protons into a target and produce muons, to catalyze the stars nuc reactions. Could maybe increase the reaction rate to a bigga boom.

    Gary 7

  52. All the explanation is appreciated.

    But any analysis & interpretation of the observation & measurements is dependent on the model one applies to data.

    Applying a different model to the same observations & measurement will result in different conclusions.

    Mention has been made of magneto-hydro-dynamics, in other words, the study of electrified plasma dynamics.

    Electromagnetism in plasma flows is scale independent with no limit established (confirmation of scale-independence has been observed to at least 14 orders of magnitude).

    The explanations provided thus far are primarily of the gravity “only” model with some reference to MHD.

    But if one applies an electromagnetic model to the data, one can easily come to different conclusions.

    Z – pinch phenomenon are well understood and documented in plasma physics laboratories:

    http://www.plasma-universe.com/index.php/Pinch

    If one applies that model of the phenomenon then one comes to a different conclusion from the primarily gravity “only” model’s conclusions.

    To refresh my question: How does a near to exploding star have the same shape as a star forming region (why the beginning and ending are similar) ?

    The answer is easy to explain: The processes governoring the processes are the same. The Z- pinch process constrains both how a star forms and how it ends. In the ending senario, the current is increased until the circuit overloads and explodes, i.e., exploding double layers.

  53. Alan

    Let’s remember the laws of time travel. At 25,000 LY away, we are seeing this as it was 25,000 years ago. It may have already exploded and we will not know it until the light from the event reaches us. So predictions seem pointless.

  54. ND

    Gary Ansorge,

    Yeah, the biggest problem with that episode was how small the stargate was compared to the star.

  55. Theron Pray

    Funny, it looks exactly like chromosomes being pulled apart during mitosis.

    It would be awesome to see a supernova with my own eyes, thanks for the info! You’ve got another reader. :)

  56. Sili

    What? No “puppy” jokes?

  57. Janis

    Last night (November 19th at approx 1:45AM PT) I was still awake laying with my eyes closed in bed. I have a good view of the stars from my cathedral windows – With my eyes closed, saw a bright flash of light and opened them to see a star (or something in space) flash big, then die down like a match, then gone…could this have been THIS supernova? I cannot find any info anywhere on this event last night…

    If this was not a supernova, anyone know what it was?

  58. hmmm 25,000 light years away… lets see 186,000 miles per second times 60 seconds times 60 minutes times 24 hours times 365 days times 25,000 years… thats a tad more than a stones throw. Given the distance, its probably already happened and the light is still headed in our direction.

  59. DrFlimmer

    @ Janis

    Sorry, to destroy your hope, but a supernova does not rise or fade very quickly. In fact, they tend to shine for several weeks and fade very slowly. I read somewhere that this special supernova in this thread would be visible with the unaided eye for about 3 month.

    So what else could it have been? A meteor, a satellite or the ISS (did you see some movement? But even if you detected none does not rule out these possibilities). It could even have an earthly cause.

  60. Peter B

    Davis asked: “How is it then possible that this star 25,000 light years away will blast light/matter at such a speed that it will reach earth in 1 minute. Am i missing something here?”

    Yes you are. Read again what the BA said: “…it ejected a lot of matter…at very high speed, about 24 million kilometers per hour (14 million mph). That would reach from the Earth to the Moon in one minute flat.”

    So not from the supernova to the Earth in one minute, but at a speed which would allow it to travel the distance between the Earth and the Moon in one minute.

  61. tayga

    OK, I can follow the reasoning behind the accretion disc constraining this material so it only comes out along an axis of symmetry but why doesn’t it then fan out? A radiating point inside a cylinder would produce two roughly conical emissions surely? These are definitely constrained to cylinders but why? And what’s with the extra lobes at the limits of the structure that start to appear at Oct 2006?

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