WASP-18b is an extrasolar planet that is notable for having an orbital period of less than one day. It has a mass equal to 10 Jupiter masses,[1] just below the boundary line between planets and brown dwarves, about 13 Jupiter masses. Due to tidal deceleration, it is expected to spiral towards and eventually merge with its star, WASP-18, perhaps in about a million years. The planet is approximately 1.9 million miles from its star, which is about 325 light years from Earth. It was discovered by Coel Hellier, a professor of astrophysics at Keele University in England.[2]
Scientists at Keele and at the University of Maryland are working to understand whether the discovery of this planet so shortly before its expected demise (with less than 0.1% of its lifetime remaining) was fortuitous, or whether the system might not be behaving as current theory predicts.[3][1] Observations made over the next decade should yield a measurement of the rate at which WASP-18b's orbit is decaying.[4]
The closest example of a similar situation in our own solar system is Mars' moon, Phobos. Phobos orbits Mars at a distance of only about 5,600 miles, 40 times closer than our moon is to the Earth,[5] and is expected to be destroyed in about eleven million years.[6]
See also
References
- ^ a b Hellier, Coel (2009-08-27). "An orbital period of 0.94 days for the hot-Jupiter planet WASP-18b". Nature. 460. Nature Publishing Group: 1098–1100. doi:10.1038/nature08245. Retrieved 2009-08-28.
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suggested) (help) - ^ Suicidal planet seems on death spiral into star, breitbart.com, August 26, 2009
- ^ Hamilton, D. P. (2009-08-27). "Extrasolar planets: Secrets that only tides will tell". Nature. 460. Nature Publishing Group: 1086–1087. doi:10.1038/4601086a. Retrieved 2009-08-28.
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(help) - ^ Thompson, Andrea (2009-08-26). "Newfound Planet Might Be Near Death". Space.Com. Imaginova. Retrieved 2009-08-28.
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(help) - ^ Astrophysicists puzzle over planet that's too close to its sun, Los Angeles Times, August 27, 2009
- ^ Sharma, B. K. (2008-05-10). "Theoretical Formulation of the Phobos, moon of Mars, rate of altitudinal loss". arXiv. Retrieved 2009-08-28.
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