The Astronomy Thread

Scientists on the Rosetta mission have found oxygen in the gas cloud around comet 67P in what they described as the most surprising discovery about the comet to date. It is the first time that molecular oxygen - the form of the gas we breathe - has been detected on a comet, and points to a gentle birth for comet 67P some time before the formation of the solar system.

...The finding is puzzling because oxygen is highly reactive and scientists do not expect it to hang around for long in space. "We had never thought that oxygen could 'survive' for billions of years without combining with other substances," said Altwegg.

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When a star is oblate, it has a larger radius at its equator than it does at its poles. As a result, the poles have a higher surface gravity, and thus higher temperature and brightness. Thus, the poles are "gravity brightened", and the equator "gravity darkened."

The star becomes oblate (and hence gravity darkening occurs) because the centrifugal force resulting from rotation creates additional outward pressure on the star.

This creates patches of darker and lighter regions within these kinds of stars, so the light curves that make it back to Earth won't look completely uniform. What's more, planets often orbit "obliquely" from Earth's perspective and do not pass directly in front of a star.

So those especially weird light curves from KIC 8462852 could easily be caused by planets passing in front of darker and lighter regions - not alien artifacts floating around it.

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opiate82_sl said:

Sounds like they've come up with a more reasonable explanation than "alien mega-structure!" or "ummm... I guess it COULD be comet debris" for the strange dimming around KIC 8462852.

That 'alien megastructure' might be a lopsided star - Business Insider



TL;DR could be caused by planets orbits if the star isn't actually spherical.

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LachiusTZ_sl said:

Most 'Other Earths' Have Yet to Be Born

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