Two groups of astronomers have taken the first pictures of planets going around other stars. The achievement, the result of years of effort on improved observational techniques and better data analysis, presages more such discoveries and will open the door to new investigations and discoveries of what planets are and how they came to be formed. Professor C. Marois is the leader of a team that recorded three planets circling a star known as HR 8799 that is 130 light years away in the constellation Pegasus. The other team, led by Professor Paul Kalas of California University, found a planet orbiting the star Fomalhaut, 25 light years away from earth, in the constellation Piscis Austrinus.
The planets appear as fuzzy dots that move slightly around their star from exposure to exposure. Astronomers who have seen the images agreed these looked like the real things. More than 300 so-called extra-solar planets have been found circling distant stars, making their discovery the hottest growing field in astronomy.
The observations have been made mostly indirectly, by lips in straight as planets cross in front of their home star or by wobbles they induce. Astronomers being astronomers, they want actually to see these worlds, but a few, recent claims of direct observations, have been made. The new planetary systems are anchored by young bright stars more massive than our own sun and swaddled in large discs of dust, the raw material of worlds. The three planets obtaining HR 8799 are roughly ten, nine and six times the mass of Jupiter and orbiting their star in periods of 450, 180 and100 years, respectively, all counterclockwise.
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