The August General Meeting will be Tuesday the 21st at 7:30 PM. We will be located in the classroom under Regis Hall due to a conflict with a St Ignatius group, otherwise the details are the same. Our speaker is Barnaby Norris, PhD candidate at USyd, who made the science publications and the SMH a few months ago with a paper published in Nature about dusty red giant stars and how they throw off their masses. He’ll talk to us on this subject, and his abstract follows:
During the death throes of the red giant stars known as AGB (Asymptotic Giant Branch) stars, they release enormous amounts of dust and gas back into the galaxy, which goes on to form the next generation of stars and planets. These dying stars account for 75% of mass loss in the galaxy. But the mechanism by which this happens is poorly understood – how do these dusty behemoths manage to blast away such huge quantities of matter? In this talk, I will highlight some exciting new results wherein we imaged, for the first time, the dusty layers close to the star, which revealed key insights into the mass-loss process (Nature 2012, 484, pp 220-222). These discoveries were made using an exciting new observational technique, based on the art of astronomical interferometry, which allowed us to virtually switch-off the seeing and ‘take the twinkle out of the stars’, permitting extremely high-resolution images to be made. Combined with polarisation measurements, we were able to distinguish the faint, tenuous dust just milli-arcseconds away from the blazing bright star.
In this talk, in addition to discussing the astrophysical processes we uncovered, I will introduce the fascinating world of astronomical interferometry and explain how our new technique works.
As usual, visitors are welcome.