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Non-Spherical Stars
An anonymous reader writes "Now that the large interferometers are coming on line, the stars are no longer dots. Achernar (Alpha Eridani), is a huge ellipsoid whose polar radius (due to fast spinning) is 50% smaller than the equatorial one!"
I really don't think the fact that the star isn't a perfect sphere is surprising. The fact that we can measure it is a breakthrough. If we look at the sun, we can see that isn't a perfect sphere. It's not very much an ellipsoid either, but you could imagine a star (much younger) that spins very fast and is more like an ellipsoid. Even Jupiter (and also the earth!) are somewhat flattened.
The earth is not a sphere either. Any celestial body with a reasonable angular velocity will be slightly elliptical.
,i>Possibly not conforming to known ideas regarding rotating solid masses in general.
Well that makes sense, seeing as how this isn't a solid mass in the first place.
"We returned the General to El Salvador, or maybe Guatemala, it's difficult to tell from 10,000 feet"
The earth is not a 'solid mass' either.
IIRC, it is composed of a 'liquid' core that is rotating as well (and faster than the rotation of the earth about the sun).
No planet, to anything other than a zeroth order calculation, follows the I=MR^2 rule of solid spheres for inertial mass.