"We think that these small, round clouds have broken off from tall, dusty pillars of gas which were sculpted by the intense radiation from young stars. The study shows that the tiny clouds are moving outwards through the Rosette Nebula at high speed, about 80 000 kilometres per hour. The most massive of them can form so-called brown dwarfs," says team member Carina Persson, astronomer at Chalmers University of Technology.īrown dwarfs, sometimes called failed stars, are bodies whose mass lies between that of planets and stars. That tells us that many of them will collapse under their own weight and form free-floating planets. "We found that the globulettes are very dense and compact, and many of them have very dense cores. Now we have much more reliable measures of mass and density for a large number of these objects, and we have also precisely measured how fast they are moving relative to their environment," he says. Previously we were able to estimate that most of them are of planetary mass, less than 13 times Jupiter's mass.
"They are very small, each with diameter less than 50 times the distance between the Sun and Neptune. "The Rosette Nebula is home to more than a hundred of these tiny clouds - we call them globulettes," says Gösta Gahm, astronomer at Stockholm University, who led the project. They collected observations in radio waves with the 20-metre telescope at Onsala Space Observatory in Sweden, in submillimetre waves with APEX in Chile, and in infrared light with the New Technology Telescope (NTT) at ESO's La Silla Observatory in Chile. New observations of tiny dark clouds in space point out another possibility: that some free-floating planets formed on their own.Ī team of astronomers from Sweden and Finland used several telescopes to observe the Rosette Nebula, a huge cloud of gas and dust 4600 light years from Earth in the constellation Monoceros (the Unicorn). Until now scientists have believed that such "rogue planets," which don't orbit around a star, must have been ejected from existing planetary systems.
Previous research has shown that there may be as many as 200 billion free-floating planets in our galaxy, the Milky Way.
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