Billions of planets in the galaxy
Approximately 25 percent of the stars of the type of our Sun can have a planet of the size of the Earth in orbit around them according to a new study sponsored by Nasa.
Near a star known four in our galaxy possess a planet. N.A.S.A. / SIPA
Researchers of Berkeley used measures Doppler made with the telescope Keck of the Hawaiian Islands to study 166 stars of type G and K, situated unless 80 light years of the Earth. The sun is the most known for stars G, which are generally yellow, whereas stars K are smaller and of orange-red complexion.
Their purpose: to detect planets of 3 in more of 1000 times the size of the Earth and orbiting has nearness of their stars.
Only 22 observed stars had detectable planets, 33 in everything, in this range of masses and orbitales distances. After statistical correction, the authors who publish their results in the magazine Science, consider that approximately 1,6 percent of the stars of solar type has planets of the size of Jupiter and 12 percent had super-Earth (between 3 and 10 ground masses).
" For approximately 100 stars of solar type, one or two have planets of the size of Jupiter, about six have a planet of the size of Neptune, and approximately 12 have super-Earth between three and 10 ground masses ", declared A.W. Howard, an astronomer at the university of Berkeley. " If we extrapolate up to planets close to the Earth (between 0.5 and 2 ground masses) we predict that you will find there approximately 23 out of 100 stars ".
Because the researchers detected only planets close to their stars, he could have there some more of planets of ground size at bigger distances.
Their purpose: to detect planets of 3 in more of 1000 times the size of the Earth and orbiting has nearness of their stars.
Only 22 observed stars had detectable planets, 33 in everything, in this range of masses and orbitales distances. After statistical correction, the authors who publish their results in the magazine Science, consider that approximately 1,6 percent of the stars of solar type has planets of the size of Jupiter and 12 percent had super-Earth (between 3 and 10 ground masses).
" For approximately 100 stars of solar type, one or two have planets of the size of Jupiter, about six have a planet of the size of Neptune, and approximately 12 have super-Earth between three and 10 ground masses ", declared A.W. Howard, an astronomer at the university of Berkeley. " If we extrapolate up to planets close to the Earth (between 0.5 and 2 ground masses) we predict that you will find there approximately 23 out of 100 stars ".
Because the researchers detected only planets close to their stars, he could have there some more of planets of ground size at bigger distances.
Aucun commentaire:
Enregistrer un commentaire