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5 December 2013 11:26 am ,
Vol. 342 ,
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
Thousands of scientists in the Russian Academy of Sciences (RAS) are about to lose their jobs as a result of the...
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
- 5 December 2013 11:26 am , Vol. 342 , #6163
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ScienceShot: Weighing an Alien Planet
27 June 2012 2:15 pm
Step on a tilted scale and it probably won't read your weight right. Planet hunters have a similar problem: When they detect a planet tugging on its star, they often don't know how tilted the planet's orbit is—and so they can't measure the world's exact mass. Now, as astronomers report online today in Nature, infrared spectra from the Very Large Telescope in Chile have unveiled the orbital tilt of one of the first planets ever found, allowing the researchers to derive its true mass. Located 51 light-years from Earth, this planet—named Tau Boötis A b—is a "hot Jupiter" that whirls around its sun every 3 days, 7 hours, and 30 minutes. The astronomers discovered carbon monoxide in the planet's air. Coupled with the orbital period, the poison gas's Doppler shift reveals that the planet's orbit is tilted 45° to our line of sight and that the world itself weighs six times more than Jupiter . Furthermore, the spectra of the carbon monoxide molecules indicate that unlike many other hot Jupiters, the planet's atmosphere has no temperature inversion; instead, temperature drops with increasing altitude. The reason? Tau Boötis A spins fast and emits ultraviolet radiation, which destroys compounds in the planet's upper air that would otherwise absorb starlight, heat up, and cause the temperature to rise with altitude.
*Update on 28 June: On 1 July in Astrophysical Journal Letters, another team of astronomers reports detecting carbon monoxide in the planet's atmosphere and derives an orbital tilt and planetary mass that agree with the results above.
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