How red giant stars lose weight 'revealed'



How red giant stars lose weight `revealed` Washington: Astronomers claim to have finally revealed how the red giant stars of our galaxy lose massive weight every year -- winds from the upper atmosphere of the heavenly bodies are responsible for the process.

An international team says the winds that stream from the upper atmosphere of the red giant stars are responsible for removing massive amounts of matter, a finding which has profound implications across astronomy and beyond.

Using a state-of-the-art telescope at one of the world's leading observatories in Northern Chile, the team has created images of the faint starlight glinting off an unexpected halo of dust grains around the red stars.

"The grains that we have discovered here will come as a real shock to the accepted wisdom in the field. They are both much larger and much closer to the stellar surface than anyone expected," Barnaby Norris at Sydney University, who led the team, said.

This could be a critical new piece in the puzzle of how these old, dying stars manage to drive such powerful winds, say the astronomers.

"These myriad specks of dust seem entirely unimportant individually, but each one can act as a minute solar sail catching the rays of light from the star and adding its infinitesimal push to the gas, creating the wind," Prof Peter Tuthill, a team member, said in a release.



"Even more remarkable, the grains themselves are transparent like powdered glass, but so incredibly fine so as to appear like smoke. It is hard to imagine such a glittering halo doing the heavy lifting of more than an entire earth each year," he added.

The majority of the chemical elements critical to the formation of Earth-like planets and life come from the winds driven from dying red giant stars.

"Hopefully our findings will help to illuminate a key step in the grand cycle as matter is expelled from stars into the galaxy only to seed new generations of stellar and planetary birth," Barnaby said.

The findings have been published in the 'Nature' journal.

PTI