
Astronomers may have found giant alien 'megastructures' orbiting star - awjr
http://www.independent.co.uk/news/world/forget-water-on-mars-astronomers-may-have-just-found-giant-alien-megastructures-orbiting-a-star-near-a6693886.html
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koverstreet
Just finished reading the paper. It's worth reading - it's well written and
they've already put a lot of effort into characterizing the star, and
modelling/ruling out any explanations they could think of.

The thing that makes this star _really_ peculiar is the lack of any excess
infrared - if there was as much material (dust, asteroids, debris) orbiting
the star as you'd expect from how often/how much the star is being occulted
(that is, there should be a lot more material on orbits that don't intersect
with our line of sight) - then there should be quite a bit of excess infrared
radiation from all that material, but we don't.

The most plausible explanation they could come up with is comets - but the
profile of the occultation events doesn't match comets very well (sharp dip
initially corresponding to the optically thick head of the comet, then a
slower rise back to normal from the tail).

My question regarding the comet hypothesis is - could there even be enough
material in the oort cloud to produce the amount of occultation we're seeing?
Given that Jupiter apparently only occults our sun by 1% and we're seeing 22%
occultation here, it seems unlikely.

You'd have to assume an average object size to calculate % occultation -> mass
of occulting objects, but we should be able to make a reasonable assumption on
that from observations in our own solar system. And apparently our own oort
cloud has been estimated at a few earth masses, so if that's typical we've got
a rough upper bound for the amount of material available. I wonder if anyone's
done that calculation yet.

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DomBlack
Link to the paper
[http://arxiv.org/pdf/1509.03622v1.pdf](http://arxiv.org/pdf/1509.03622v1.pdf)

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dang
[https://news.ycombinator.com/item?id=10386214](https://news.ycombinator.com/item?id=10386214)

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fjarlq
Phil Plait's take on it:

[http://www.slate.com/blogs/bad_astronomy/2015/10/14/weird_st...](http://www.slate.com/blogs/bad_astronomy/2015/10/14/weird_star_strange_dips_in_brightness_are_a_bit_baffling.html)

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hliyan
As much as I'd like to believe it, another case like the faster-than-light-
neutrino incident is more likely than alien megastructures.

