A few years back, when I was working on using NASA satellite data to create educational materials for kids, we had this idea of using the steady beats from pulsars in a song. Pulsars are the rapidly-spinning über-dense fantastically-magnetic collapsed cores of exploded stars. As they spin, they emit beams of matter and energy that sweep out into space much like a lighthouse beam, and we see a blip of light when that beam passes over us.
Some pulsars spin hundreds of times per second, some take several seconds to spin once. If you take that pulse of light and translate it into sound, you get a very steady thumping beat with very precise timing. So making it into a song is a natural thought.
But we certainly didn’t take it as far as the German band Reimhaus did, making a music video out of it! They used several pulsars for their song "Echoes, Silence, Pulses & Waves". So here’s the cosmic beat:
If you’re a fan of over-the-top ridiculously huge violent explosions, then you won’t do any better than gamma-ray bursts. With apologies to Douglas Adams and Eccentrica Gallumbits, GRBs are the Universe’s largest bangs since The Big One. When they were first discovered, during the Cold War, it was unclear what caused them. There were more theories than there were observations of them! Now we’ve observed hundreds of these things, and we’ve learned quite a bit about them, like a) every one of them is different, 2) they have lots of different sources, and γ) even after five decades they can still surprise us.
Last year on Christmas, the light from a gamma-ray burst reached Earth and was detected by NASA’s orbiting Swift satellite. Designated GRB 101225A, it was weird right off the bat: it lasted a staggering half hour, when most GRBs are over within seconds, or a few minutes at most. Followup observations came pouring in from telescopes on and above the Earth, and the next weird thing was found: the fading glow from the burst seemed to be coming from good old-fashioned heat: some type of material heated to unbelievable temperatures. Usually, the afterglow is dominated by other forces like rapidly moving super-intense magnetic fields that accelerate gigatons of subatomic particles to huge speeds, but in this case it looked like a regular-old explosion.
Both of these things are pretty dang weird. So what could have caused this burst?
Normally, we think GRBs are the birth cries of black holes. When a giant star explodes, or two tiny but ultra-dense neutrons stars merge, they can form a black hole and send vast amounts of gamma rays (super high-energy light) sleeting out into the Universe. In this case, though, something different happened, and two ideas of what was behind it are emerging…. but both involve neutron stars. And I’m not sure which idea is cooler.
If you were wondering what was going on with the bright new supernova in the spiral galaxy M101, it’s now getting very difficult to observe due to its proximity to the Sun in the sky. But happily my friend, the accomplished astronomer Travis Rector, got a shot of it using the Mayall 4-meter telescope at Kitt Peak National Observatory. I would venture to say it’s one of the prettiest ones I’ve seen so far:
[Click to Chandrasekharenate.]
This was taken on September 18th, and the supernova is the bright blue star above and to the right of the center of the picture (to the left of the fuzzy red nebula). Pictures like this are important in pinning down the exact location of the supernova in the galaxy, so that after it fades the potential prescursor star can be found (though in this case, we already have pretty decent Hubble images of the field). Also, of course, big telescopes with sensitive detectors can give very accurate brightness measurements, which are absolutely critical in understanding how these objects change with time. This particular flavor of supernova is key to our understanding the size and scale of the Universe itself, so the more data — and the more accurate the data — we have, the better.
Image credit: T.A. Rector (University of Alaska Anchorage), H. Schweiker & S. Pakzad NOAO/AURA/NSF
Some new research just released asks a question near and dear to me: are there thousands of spinning white dwarfs in our galaxy, just waiting to explode as they gradually slow their rotation?
The answer is very probably yes. Let me be clear, as I always must be when covering topics like this: we’re not in any real danger from these things. Space is vast, and supernovae are few. If these things were that volatile we wouldn’t be here to talk about them in the first place.
But it’s still a very cool scientific question, and actually a fairly simple concept. Here’s how it works.
Imagine a binary system of two stars like the Sun, orbiting each other. One star nears the end of its life, swells up into a red giant, and blows off its outer layers. After a few millions years, all that’s left is its core: a dense, hot ball called a white dwarf. The size of the Earth but with the mass of a star, white dwarfs are pretty weird. They have incredibly strong gravity, which wants to crush them down even further, but they are supported by the electric repulsion of electrons, which is a pretty mighty force. It’s an uneasy truce.
It’s made even uneasier by the other star. It too eventually swells up, and can start to dump matter onto the dwarf (like in the picture above). If enough mass piles up, the immense gravity of the dwarf can induce nuclear fusion. Sometimes the material explodes, flaring in brightness, and we get a nova. Other times, if enough matter piles up — making the total mass of the white dwarf a bit more than 1.4 times that of the Sun — the ignition of fusion can cause a runaway reaction in the star, disrupting it entirely. The white dwarf tears itself apart, and you get one of the biggest and most violent explosions in the Universe: a supernova.
A couple of weeks ago, astronomers spotted a star exploding in the nearby face-on spiral M101. They quickly determined it was a Type Ia, the kind used to calibrate the cosmic distance scale, and therefore a star of exceeding importance: we don’t see them close by (well, if 20+ million light years is "close", which it is to astronomers) very often. This one promised to get bright enough to study extremely well, which will help us understand these "standard candles" better.
The supernova is labeled. It was found by the Palomar Transient Factory, a group of folks looking for nearby supernovae, and was given the temporary name PTF 11kly; the official designation is SN 2011fe, the 136th supernova seen so far in 2011 (they’re named alphabetically for a given year, so the first 26 are 2011a – z, the second 26 are 2011ba – bz, etc.). This image was taken using a 0.8 meter telescope at the Las Cumbres Observatory Global Telescope Network; that’s a relatively small ‘scope, which tells you this a pretty bright object!
In fact, it appears to be reaching its peak brightness right now, and should be visible in binoculars. If you have a good view of Ursa Major, currently in the northwest at sunset, finding it shouldn’t be too difficult. Any decent star chart will show it (here’s one on wikipedia, for example). It’s raining here in Boulder (figures) but I’m hoping to get a chance to see it with my binoculars soon. Supernovae usually brighten for a couple of weeks and then fade more slowly, so if you can’t see it tonight or tomorrow it’s not critical, but of course the sooner you look the better.
Image credit: BJ Fulton/LCOGT. Tip o’ the accreting white dwarf to Dan Vergano (you should follow him on Twitter for lots of sciencey updates).
Images are starting to come in already of the new supernova in the nearby spiral galaxy M 101. Here’s a color image of the exploding star from the Faulkes North telescope on — wait for it — Haleakala:
[Click to embiggen.]
That’s color and very pretty, but I think this one is more impressive, showing the supernova gaining in brightness by a factor of six in a single day:
[Again, click to endeflagrate.]
That’s taken by the Palomar 48 inch telescope in California. The images show M 101 on August 22, 23, and 24. You can see (or not see in this case) how it wasn’t there on the first night, shows up on the second, and is now much brighter. It will get brighter yet, and may get into range of visibility using good binoculars! Certainly even a small telescope will be able to see this supernova once it reaches maximum brightness, which won’t happen for at least a week, if not more.
Right now, the Moon is a waning crescent, so it won’t be a problem for 10 days or so. If you have a telescope and a camera, get out there!
Credits: BJ Fulton, LCOGT; Peter Nugent and the Palomar Transient Factory
Attention all astronomers! There is a new Type Ia supernova that has been seen in the nearby spiral galaxy M101, and it’s very young — currently only about a day old! This is very exciting news; getting as much data on this event as possible is critical.
Most likely professional astronomers are already aware of the supernova, since observations have already been taken by Swift (no X-rays have yet been seen, but it’s early yet) and Hubble observations have been scheduled. Still, I would urge amateur astronomers to take careful observations of the galaxy.
[As an aside, I'll note that this supernova won't get bright enough to see naked eye and poses no threat at all to us here on Earth. It may be visible in decent-sized telescopes, though, and as you'll see this may be a very important event in the annals of astronomy.]
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
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A few years back, when I was working on using NASA satellite data to create educational materials for kids, we had this idea of using the steady beats from pulsars in a song. Pulsars are the rapidly-spinning über-dense fantastically-magnetic collapsed cores of exploded stars. As they spin, they emit beams of matter and energy that sweep out into space much like a lighthouse beam, and we see a blip of light when that beam passes over us.
