asteroseismology tagged posts

This image shows a planet being stripped by host star’s heat. Credit: Peter Devine

Astrophysicists at the Uni of Birmingham have used data from the NASA Kepler space telescope to discover a class of extrasolar planets whose atmospheres have been stripped away by their host stars. Planets with gaseous atmospheres that lie close to their host stars are bombarded by a torrent of high-energy radiation. Due to their proximity to the star the ‘envelopes’ have been blown away by intense radiation. This violent ‘stripping’ occurs in planets that are made up of a rocky core with a gaseous outer layer.

The scientists used asteroseismology to characterize the stars and their planets to levels of accuracy not achieved before for these systems...

Stars like the Sun puff up and become red giants towards the end of their lives. The red giants (‘old’ Suns) of the same mass as the Sun do not show strong magnetic fields in their interior, but for stars slightly more massive, up to 60 percent host strong magnetic fields. Credit: University of Sydney

Finding to impact understanding of stellar evolution and potentially lead to a better understanding of the sun’s 22-year magnetic cycle – known to affect communication systems and cloud cover on Earth. Using data from NASA’s Kepler mission, the team found that stars only slightly more massive than the Sun have internal magnetic fields up to 10 million times that of Earth, with important implications for evolution and the ultimate fate of stars.

“This is tremendously exciting, and totally unex...

Artistic representation (not to scale) of a red giant star with strong internal magnetic fields. Waves propagating through the star become trapped within the stellar core when a strong magnetic field is present, producing a “magnetic greenhouse effect” that reduces the observed amplitude of stellar pulsations. Credit: Rafael A. García (SAp CEA), Kyle Augustson (HAO), Jim Fuller (Caltech) & Gabriel Pérez (SMM, IAC), Photograph from AIA/SDO

Using asteroseismology, which uses sound waves generated by turbulence on the surface of stars to determine their inner properties scientists found the fusion-powered cores of red giants, stars that are evolved versions of our sun, are strongly magnetized. The findings will help astronomers better understand the evolution of stars.

“In the same way medi...