Image of the Day: Rare Glimpse of a Spectacular Protostar




Using combined data from a trio of orbiting X-ray telescopes, including NASA's Chandra X-ray Observatory and the Japan-led Suzaku satellite, astronomers have obtained a rare glimpse of the powerful magnetic fields that drive torrents of gas into the stellar surface, where they heat large areas to millions of degrees. X-rays emitted by these hot spots betray the newborn star's rapid rotation, showing that it is spinning so quickly it is on the verge of breaking up.

The nebula M78, a star formation region located in our galaxy about 1300 light years from earth harbors McNeil's Nebula, first noticed in 2004 when it was lit up by a protostar named V1647 Orionis, a stellar infant still partly swaddled in its birth cloud. Protostars have not yet developed the energy-generating capabilities of a normal star such as the sun, which fuses hydrogen into helium in its core. For V1647 Ori, that stage lies millions of years in the future. Until then, the protostar shines from the heat energy released by the gas that continues to fall onto it, much of which originates in a rotating circumstellar disk.

V1647's agnetic fields and intense X-ray hot spots thousands of times hotter than the rest of the star, are thought to be the footprints of streams that transfer gas from a disk that still surrounds the young star. Scientists think that magnetic reconnection events–the energy source for outbursts from our own sun–channel and drive the gas flows. The star, which spins once in about a day, rotates faster than the disk, and constantly winds up the magnetic fields, which release a great deal of energy when they snap back into lower-energy states. This protostar's X-ray variations are giving astronomers a rare glimpse of energetic phenomena accompanying the "toddler" phase of a low-mass star.*The team found strong similarities among 11 separate X-ray light curves based on data from Chandra, Suzaku and the European Space Agency's XMM-Newton satellites. V1647 Ori is among the youngest stars whose spin rates have been determined using an X-ray-based technique.

The Daily Galaxy via the Chandra X-Ray Observatory



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