A Chalmers-led team of astronomers has for the first time observed details on the surface of an aging star with the same mass as the Sun. ALMA:s images show that the star is a giant, its diameter twice the size of Earth’s orbit around the Sun, but also that the star’s atmosphere is affected by powerful, unexpected shock waves. The research is published in Nature Astronomy on 30 October 2017.
A Chalmers-led team of astronomers has for the first time observed details on the surface of an aging star with the same mass as the Sun. ALMA:s images show that the star is a giant, its diameter twice the size of Earth’s orbit around the Sun, but also that the star’s atmosphere is affected by powerful, unexpected shock waves. The research is published in Nature Astronomy on 30 October 2017.
?A team of astronomers led by Wouter Vlemmings, Chalmers University of Technology, have used the telescope Alma (Atacama Large Millimetre/Submillimetre Array) to make the sharpest observations yet of a star with the same starting mass as the Sun. The new images show for the first time details on the surface of the red giant W Hydrae, 320 light years distant in the constellation of Hydra, the Water Snake.
W Hydrae is an example of an AGB (asymptotic giant branch) star. Such stars are cool, bright, old and lose mass via stellar winds. The name derives from their position on the famous Hertzsprung-Russell diagram, which classifies stars according to their brightness and temperature.
– For us it’s important to study not just what red giants look like, but how they change and how they seed the galaxy with the elements that are the ingredients of life. Using the antennas of Alma in their highest-resolution configuration we can now make the most detailed observations ever of these cool and exciting stars, says Wouter Vlemmings.
Read more at Chalmers University of Technology
Image: 320 light years from Earth, the star W Hydrae is a few billion years further on than the Sun in its life. For comparison, the dotted ring shows the size of the Earth's orbit around the Sun, seen from an angle. (Credit: Alma (ESO/NAOJ/NRAO)/W. Vlemmings)
