Researchers have found that the rotation of inner core of old stars called as “red giants”, which in most cases have radius 5 times the radius of the sun. This study gives an insight about our sun that what our sun will be look like in five billion years.
This research has been done by a team of researchers led by PhD student Paul Beck from Leuven University in Belgium and published online in December 7 issue of the journal Nature.
Researchers have found, through ultra high precision of the data from NASA’s Kepler space telescope, that the inside core of the red giant stars spin ten times faster, completing one rotation in a month, than the outside surfaces, which often take almost a year or so to complete.
Beck and his collaborators studied waves moving through the stars appearing on the surface as rhythmic variations in the brightness of the stars. The study of such waves is called as asteroseismology. Different waves showed different parts of the star and by comparing the waves travelling towards inner core of the star, researchers were able to find the speed of the inner core and the outer surface.
“It is the heart of a star, which determines how it evolves“, says Beck, “and understanding how a star rotates deep inside helps us to understand how stars like our Sun will grow old.”
Paul G. Beck, Josefina Montalban, Thomas Kallinger, Joris De Ridder,Conny Aerts, Rafael A. García, Saskia Hekker, Marc-Antoine Dupret, Benoit Mosser, Patrick Eggenberger, Dennis Stello, Yvonne Elsworth, Søren Frandsen, Fabien Carrier, Michel Hillen, Michael Gruberbauer, Jørgen Christensen-Dalsgaard, Andrea Miglio, Marica Valentini, Timothy R. Bedding, Hans Kjeldsen, Forrest R. Girouard, Jennifer R. Hall & Khadeejah A. Ibrahim, (2011). Fast core rotation in red-giant stars as revealed by gravity-dominated mixed modes. Nature, doi:10.1038/nature10612