Astronomers have discovered a previously unknown process in star formation which could prevent infant stars from destroying themselves. This process involves “cosmic winds” that circulate around gas and dust clouds, which eventually collapse to form stars. These winds help to slow the spin of the forming stars. This discovery was made by scientists from the Max Planck Institute for Astronomy using radio wave observations of a young star in a cosmic cloud called CB26, located around 460 light-years from Earth.
Stars form when dense regions of cosmic clouds collapse due to their own gravity. As these clouds collapse, they rotate due to their angular momentum, which must be conserved. As the cloud shrinks and turns into a star, it rotates more rapidly. The resulting centrifugal forces can tear the forming star apart by moving matter away from the axis of rotation. This is known as the angular momentum problem of star formation.
Scientists believe that matter falling to the central region of a collapsing cloud could form an accretion disk of gas and dust around the forming star. This disk could provide additional matter needed for nuclear fusion and help carry angular momentum away from the star. As the hydrogen gas in the disk spins, it heats up and creates a magnetic field, which influences the flow of plasma. This plasma can carry away matter and angular momentum in a “disk wind”, slowing the spin of the star.
Observations of the accretion disk around a young star in CB26 showed the kind of motion characteristic of a rotating disk wind. Further observations and sophisticated modeling allowed the researchers to measure the dimensions of the outflow of matter from the disk. They found that the disk wind is wide enough to carry away a significant amount of angular momentum, potentially preventing the star from tearing itself apart. The researchers plan to continue investigating this protostar using an upgraded observatory. Their research was published in the journal Astronomy and Astrophysics.
Key Takeaways:
- Astronomers have identified a previously unknown process in star formation, involving “cosmic winds” that prevent infant stars from self-destruction due to their own spin.
- Scientists reached this conclusion by observing a young star in a cosmic cloud, and modeling the flow of matter around it, revealing how some stars form without their own rotation tearing them apart.
- The research found that the disk wind around the forming star is wide enough to carry away a significant amount of angular momentum, thus protecting the star from ripping itself apart.
“Astronomers have discovered an important step in star formation, hitherto unknown, that could save infant stars from ripping themselves apart. The rescue mechanism is associated with “cosmic winds” that blow around clouds of gas and dust — and it’s these clouds that eventually collapse to form hot and dense stellar bodies. Plus, the clouds manage to slow these forming stars’ spins.”
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