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Astronomers Determine the Length of Day of an Exoplanet

Posted by Soulskill on Wednesday April 30, 2014 @08:10AM from the now-we-know-when-to-launch-sneak-attacks dept.

The Bad Astronomer writes: "Astronomers have just announced that the exoplanet Beta Pic b — a 10-Jupiter-mass world 60 light years away — rotates in about 8 hours. Using a high-resolution spectrometer and exploiting the Doppler shift of light seen as the planet spins, they measured its rotation velocity as 28,000 mph. Making reasonable assumptions about the planet's size, that gives the length of its day. This is the first time such a measurement has been achieved for an exoplanet."

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At what point is it a star? by HeckRuler · 2014-04-30 08:49 · Score: 4, Informative

Beta Pic b — a 10-Jupiter-mass world
How is that not a star?
I thought Jupiter was half-way to critical mass where it all explodes into a fireball?
Searching...
Nope. I was wrong. Jupiter would need about 75 times more mass before it went nuclear, fused hydrogen at it's core and became a star. A 10-Jupiter mass planet is totally legit.