Today's exoplanet weather: 1,000°C, glass rain, 8,700 km/h winds Those readers who enjoy complaining about the weather might like to consider a short weekend break on 'hot Jupiter' exoplanet HD 189733b, where conditions will give them something to really moan about. Studies of HD 189733b – discovered in 2005 transiting the star HD 189733, which lies some 63 light years from Earth in the …
"the atmosphere must be boiing off at a fantastic rate even with the relatively strong gravity"
And Wikipedia doth spoke unto the internet "this planet is evaporating at a rate of 1-100 gigagrams per second."
Using the upper bound of 100 million kilograms per second, and noting the mass of 1.162 Jovian masses (or 2.2 x 10^27 kg), you'll need 2x10^19 seconds to evaporate it, or 697 billion years. At the lower bound, multiply that by a factor of 100.
But that's a sloppy linear extrapolation. As the mass drops, escape velocity will drop and the mass loss will accelerate on an exponential curve that I'm too lazy to calculate.
On the gripping hand, the K1V primary of 0.846 solar masses has a main sequence life span of 15 billion years, so I doubt the planet will boil away before it has to deal with red giant problems. With a near-circular 0.03AU orbit, HD 189733b will have a front row seat to such stellar change-of-life issues.
While I applaud your calculations, I'll have to mark you down for use of non-standard units.
The correct measurement of mass on El Reg is the Jub (the mass of the planet being 5.23 x 10^23 KiloJubs). Do keep up.
http://www.theregister.co.uk/Design/page/reg-standards-converter.html
"The correct measurement of mass on El Reg is the Jub (the mass of the planet being 5.23 x 10^23 KiloJubs). Do keep up."
Someone mentioned "free donuts!" and I prioritized reaching the donut box before the descending horde over niceties like unit conversions. Hence my crude and unpolished post, for which I apologize.
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how can a gas giant be both tidally locked and have circulating 5000mph winds?
gasses are quite difficult to 'lock' into place.
the researchers also say that they compensated for the planets spin, but if it's locked then its spin is the same period as its orbit and over a transit period won't have rotated much at all...
confused.com
Ignoring the possibility of a solid core most of the planet will not be gas but liquid. This can become tidally locked* (especially if its viscous) but this still leaves the atmosphere to move around. As one side is facing its sun it gets very hot and the other side is cold. This is all is a small butterfly to flap its wings and the temperature differences will whip up massive storms and winds - especially when you have glass precipitating out.
Even the small rotation as it rotates round the sun is enough to generate a pretty hefty Coriolis effect.
* there's probably a surface layer of relatively free moving liquid.
This place is the anti-Skegness. Sure, there's a screaming gale off the sea and it's pissing it down. The difference is that the precipitation is warm - thus eliminating the risk of freezing to death. You'll need some pretty good sunblock but your deckchair will still blow over. I bet the nightlife is better than Skeggy too...
One thing is clear; if it does have intelligent life they won't be arguing about the desirability of building wind turbines. A simple nickel alloy rotor a few tens of centimetres in diameter will drive the air conditioning for an average household. But being a wind turbine servicebeing would not be a fun job.
It's not that long ago [well within my adult lifetime and I'm not *that* old] that we were only able to speculate on the probability that there were planets orbiting other starts.
Now, not only have we found and catalogued thousands of the buggers, we're even able to speculate on their composition and calculate the wind-speeds in their atmospheres. Quite mind-blowing, when you think about it.
Hats off to the astro-boffins and trebles all round!
They have determined the wind speed on a planet 63 light years away by measuring the Doppler shift in a gas in the atmosphere of said planet as it crosses the glaring face of its parent star?
Wow. Just F'ng wow.
I know others have already commented on it but it hears repeating.
Wow, Just F'ng wow.
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