3 Dec

Star formation caught in the act

first_imgIn teenagers as in stars, the first years of life are times of great change. A massive protostar that lies about 4250 light-years from Earth has undergone a dramatic evolution over the course of just 18 years, a new study reveals. In 1996, when scientists used a radio telescope to observe a star-forming region dubbed W75N(B), one of the objects in that cloud—called VLA 2—had very little structure: Its magnetic field wasn’t oriented in any particular direction, and the ionized material streaming from the star—its version of solar wind—spewed outward at similar speeds in all directions. But observations last year hint that the protostar’s stellar wind was flowing more quickly from the object’s poles (relative speeds depicted in bluish ovoid in image above), and its magnetic field had become aligned with that of the larger cloud of gas and dust that surrounds it, the researchers report online today in Science. Material flowing out from the equatorial regions is slowed substantially as it runs into the doughnut-shaped disk of dust and gas that surrounds the protostar, the researchers explain. Over the next few hundred thousand years, W75N(B)-VLA 2 will evolve into a star about six times the mass of our sun, team members estimate. Another protostar forming in the same cloud of material, dubbed W75N(B)-VLA 1, sported an organized magnetic field in 1996 and therefore is farther along in its stellar evolution, likely because it’s more massive. Continuing observations of the handful of massive protostars in the cloud will shed new light on the earliest stages of star formation, enabling researchers to fine-tune their models of how such stars evolve.last_img

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