another interpretation of FRB 150418

There’s a very different take on the Fast Radio Burst 121102 published this week on Nature than the one published last week. A team using the Arecibo Observatory reports that the reported burst was accompanied by ten more bursts, and qualifying it as repeating. There’s so much weird speculation that still seems plausible that I’m baffled. They dispute that the origin of the FRB is 6 billion light years away, emitting from two colliding neutron stars.

the source of a series of fast radio bursts identified

A series of FRBs have been traced to two colliding neutron stars in a galaxy 6 billion light years away. Because LIGO is in the news, it popped into my head that LIGO could have picked up on one of these bursts too, but:

Well, damn. It’s still cool. Why is it significant?

Now that Keane and his team know the distance to the new FRB, they can use the length of the signal to reveal how much material it passed through. This could solve a longstanding mystery: precise measurements of the cosmic microwave background — the afterglow of the Big Bang — suggest that around 4% of the observable Universe today should be composed of ordinary matter (not dark energy or dark matter). But after totting up what they can see, researchers say around half that matter remains unaccounted for.

From the data Keane’s team has, it looks like the matter is really there.

KIC 84628532: It’s not comets

An astronomer checked out a century of photographic plates of the night sky to find that KIC 84628532 has been dimming for a century. It’s dimmed by 19% in that time.

Schaefer saw the same century-long dimming in his manual readings, and calculated that it would require 648,000 comets, each 200 kilometres wide, to have passed by the star – completely implausible, he says. “The comet-family idea was reasonably put forth as the best of the proposals, even while acknowledging that they all were a poor lot,” he says. “But now we have a refutation of the idea, and indeed, of all published ideas.”

So, no… It’s not comets. It also demolishes the argument that the dimming was the result of an artifact in the Kepler telescope. The phenomenon is real.

What’s going on with KIC 8462852?

KIC 8462852 is a mature star that is emitting an unusual pattern of light that suggests a large amount of objects orbiting it that are not planets. The most plausible theory is that it’s a swarm of comets, but the astronomers in this article are uncomfortable with this theory, as this event would have had to happen very recently, only a few thousand years ago. Now something that almost never happens is happening- people are seriously proposing that there is a remote possibility that these objects are artificial constructs, alien megastructures, “perhaps stellar-light collectors.” They’re pointing the VLA at the star in January:

Assuming all goes well, the first observation would take place in January, with the follow-up coming next fall. If things go really well, the follow-up could happen sooner. “If we saw something exciting, we could ask the director for special allotted time on the VLA,” Wright told me. “And in that case, we’d be asking to go on right away.”

I saw that New Scientist was already scoffing at the hype, pushing the comet swarm theory, but their article didn’t even mention the VLA news. Phil Plait has a good post on KIC 8462852. Dyson sphere, eh?