Posts Tagged ‘jets’

How Stellar Death Can Lead To Twin Celestial Jets

February 13, 2014 Leave a comment

Credit: NASA/ESA & Valentin Bujarrabal

Credit: NASA/ESA & Valentin Bujarrabal

Astronomers know that while large stars can end their lives as violently cataclysmic supernovae, smaller stars end up as planetary nebulae – colourful, glowing clouds of dust and gas. In recent decades these nebulae, once thought to be mostly spherical, have been observed to often emit powerful, bipolar jets of gas and dust. But how do spherical stars evolve to produce highly aspherical planetary nebulae?

In a theoretical paper published this week in the Monthly Notices of the Royal Astronomical Society, a University of Rochester professor and his undergraduate student conclude that only “strongly interacting” binary stars – or a star and a massive planet – can feasibly give rise to these powerful jets.

When these smaller stars run out of hydrogen to burn they begin to expand and become Asymptotic Giant Branch (AGB) stars. This phase in a star’s life lasts at most 100,000 years. At some point some of these AGB stars, which represent the distended last spherical stage in the lives of low mass stars, become “pre-planetary” nebula, which are aspherical.

“What happens to change these spherical AGB stars into non-spherical nebulae, with two jets shooting out in opposite directions?” asks Eric Blackman, professor of physics and astronomy at Rochester. “We have been trying to come up with a better understanding of what happens at this stage.”

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Hubble Movies of Supersonic Jets from Young Stars

August 31, 2011 Leave a comment

Stellar jets HH 47, HH 34 and HH 2. Image credit: NASA, ESA, and P. Hartigan (Rice University)

Stellar jets HH 47, HH 34 and HH 2. Image credit: NASA, ESA, and P. Hartigan (Rice University)

Stars  aren’t shy about sending out birth announcements. They fire off  energetic jets of glowing gas travelling at supersonic speeds in  opposite directions through space.

Although  astronomers have looked at still pictures of stellar jets for decades,  now they can watch movies, thanks to the NASA/ESA Hubble Space  Telescope.




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