Wednesday, July 6, 2016

Help -- One of our Stars is Missing!

Suppose there were amazingly advanced alien civilizations out there -- aliens capable of harnessing the energy of entire galaxies. (These are the Kardashev Type III civilizations). Surely such a civilization would easy to spot?

I've noticed a surprisingly large number of serious astronomy papers on this subject recently. As you might imagine, nobody has seen any evidence for such a civilization -- if they had seen something, you probably would have heard about it by now. But here's a fun new idea from Beatriz Villarroel and collaborators at Uppsala University: searching for disappearing stars. These scientists compared two surveys of the sky -- one from the US Naval Observatory, based on observations of the sky between 1950 and 1999, and the more recent Sloan Digital Sky Survey. They examined 10 million objects, and found exactly one object in the first survey that seems to have disappeared in the later survey.

Does this mean that an advanced civilization has caused a star to vanish?

Probably not, and the authors of the paper don't make such a claim. Maybe the star was simply much brighter in the past and then dimmed rapidly. On the other hand, it's a rather intriguing observation....


Kathy said...

Story idea:

An enthusiastic and poorly equipped amateur reads a similar post in the blog "Galactic Tales," and rushes out to look at the star where it should be today.

She finds the original observation of the missing star was an artifact that recorded a star where none should be.

Of course, that would be more than a bit anticlimactic... :)

So instead let's say she finds incontrovertible proof of a Dyson sphere now obscuring the star. She can tell, because now and then the solar collectors orbiting the star (easier to do than a solid shell millions of miles in diameter) let a bit of light through. The rest of the time, the infrared radiation (where does a poorly equipped amateur astronomer get an infrared detector?) is consistent with a star's light being intercepted near the source. Proving once and for all the fictions can be stranger than truth :)

Bobby B said...

Peter F. Hamilton's Pandora's Star/Judas Unchained used this idea as a significant plot device.