Supernova! Supernova! Supernova!

I do love a good supernova, don’t you? This latest one has just recently burst into existence in the galaxy M82. Check out this flashy little gif animation, blinking between a usual picture of the galaxy and a recent one. That bright spot on the outskirts of the galaxy marks the death of a massive, luminous star.

M82-supernova

Well… I say recently. Actually, given the distance to M82, this star actually died around 11.5 million years ago. Which was during the Miocene epoch here on Earth. So in actual fact, this supernova exploded before humans had even evolved, and the light from its explosion is only just reaching us here on Earth. Humbling stuff.

But this supernova is exciting, because even though supernovae happen all the time, one near enough to see like this is a rare event. A typical galaxy like our own may yield perhaps 3 or 4 supernovae every 100 years. Only a fraction of those will be visible to us though, because galaxies are dusty things. Thick, swirling interstellar clouds line most galaxies, and many are dense and vast enough to completely block the light from a supernova. Which, is really saying something, when you consider that a supernova can shine with the light of one hundred million suns.

Most of the supernovae we see exploding in the sky are in distant galaxies. They’re too faint to be observed without a powerful telescope, and too distant for us to pick out much detail in what we see. M82 (also known as the Cigar galaxy), on the other hand, is pretty close. 11.5 million light years is a long distance, certainly, but that’s just peanuts compared to space. In other words, this supernova is pretty nearby as astronomical distances go. So it’ll be interesting to see what we can learn as we watch the explosion occurring…

Anyway, I don’t have much time to write about this now, but I’d feel remiss if I didn’t at least mention it. Better and more detailed analyses can be had by going to visit Discovery Space, Universe Today, or the Bad Astronomer

About Invader Xan

Molecular astrophysicist, usually found writing frenziedly, staring at the sky, or drinking mojitos.
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4 Responses to Supernova! Supernova! Supernova!

  1. Baribal says:

    This is brely related, but anyways… What would you recommend to a very lazy programmer to simulate nebulae? Algorithmically, that is. I have neither problems nor qualms about working with nearly arbitrarily large numpy matrices, or learning OpenCL for that matter, but I have pretty much zero idea about what formulae I’d use to update the relevant particles or grid cells.

    • invaderxan says:

      Hmmm… I’ll be honest, simulations of that kind aren’t really my area of expertise. It would also depend a little on what kind of nebula you were interested in. As a good place to start, however, you might want to investigate smoothed-particle hydrodynamics simulations. This technique effectively describes fluid flows, and it’s used in a variety of research fields including astrophysics. Hope that’s some help?

      • Baribal says:

        It does provide a starting point,thanks. I’m feeling a bit like the formulae involved slapped me in the face with a wet fish, but I guess that that is to be expected by hydrodynamics. Also, “hydrodynamics plus gravity” seems to be the answer to the subquestion about which formulae govern the updates of each particle, although there also seems to be a provision for changing the number of particles involved on the fly, which I don’t quite understand so far.
        To provide a little context, my goal is to simulate nebulae and other stellar phenomena to generate pretty skyboxes for space games, and factoring in my rather limited knowledge about actual nebulae (which can be summed up as “They’re what happens when a star blows up, right?”), the answer to what kinds of nebulae I want to simulate is “Errr… Pretty ones?”

      • Baribal says:

        Okay, I think that by now I do get the basic basics:
        * There are particles. Each particle represents a volume of gas smeared out over a spherical space, approximating a (cut-off) gaussian distribution.
        * Each particle has a set of properties, including mass/density (usually all particles seem to share those), linear and angular momentum, and probably others.
        * The number of particles is usually constant, but a star object may just as well act as an emitter for new particles.
        * The simplest scheme to advance the simulation is: At each step, for each particle P, find all particles R within a radius of k. Plug them into a set of formulae, and out comes the new state of properties for P. Then move it accordingly. More complicated schemes involve the Leapfrog method, Runge-Kutta integration and so on.

        That being said, I can’t find a resource that enumerates the particle properties and formulae (actually I have found a part of a thesis, “Smoothed Particle Hydrodynamics” (being part 3 of said thesis, arXiv: 1007.1245v2), which contains a LOT of formulae… completely without any explanation of the symbols involved, making it practically impossible for me to follow what is going on), so… you wouldn’t happen to know an astronomer who would be able to provide those, but doesn’t really feel like to implement them?

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