April 8th, 2010

star-forming nebula

Ringworld discovered, plus aliens don't need oxygen.

First off, this could turn out to be one of the most important discoveries of all time: Astronomers have directly observed something huge (about four times the width of Earth's orbit) eclipsing another star, Epsilon Aurigae. After astronomers discovered some 200 years ago that it dims every 27 years, they postulated it was an eclipsing-binary star: two stars orbiting one another - in this case, a smaller one orbiting Epsilon Aurigae every 27 years - with their orbits on a direct line toward us, thus one star eclipses the other from our point of view.

But an odd detail threw a monkey-wrench into the theory: During the eclipse, the star briefly brightens. WTF? The theory was modified to include a cloud of gas and dust orbiting the primary star, perhaps surrounding the secondary (blue) star. What would that look like? Here's an artist's impression of this amazing and unique binary-star system. Note That the secondary star, young and blue, is mysteriously shrouded in a clinging disk of gas and dust, something we have not observed anywhere else in the universe:

Click the image to see the Wiki article about Epsilon Aurigae.

The solar winds and radiation pressure from a star are more than enough to blast such a cloud into smithereens in short order, yet here it is, 200 years later, still intact. This explanation seems pretty unlikely, but the observations make us come up with some pretty wacky explanations, like a shrouded star orbiting another star, or an invisible star (no, really, that was one hypothesis), or a black hole with an accretion disk. Here, check out this just-released video of the eclipse, showing the mysterious eclipse in action:

What's that look like to you? I have my own hypothesis, no less crazy than the currently operating ones. If you're an SF reader, you've probably heard of ringworlds, Dyson spheres, and other megastructures like these:

Halo players will recognize this one, also fans of Banks' Culture series.

Artist's impression of the megastructure from Niven's Ringworld.

Does it not make more sense that we're looking at an alien artifact, some kind of super-massive structure (such as a ringworld under construction, the relic of a long-destroyed megastructure, or a vast colony ship) rather than some mysterious form of binary system? Why not! Can't wait to learn more about this.

EDIT: Matt submits another potential Dyson Sphere, the "Cynus Bubble":

Click the image to see the story.

In related news, scientists have discovered multicellular life-forms on Earth that do not need oxygen to survive. This opens up opportunity for life on worlds we previously would have considered to be barren and lifeless. Of course, science fiction has given us oxygen-free aliens for decades, but now we have some scientific evidence to back it up. Like this little guy:

Click the image to see the BBC News story.

Once again I note that we live in amazing times!