Mira has a burst for Alma
A giant flare on the surface of Mira, a red giant closest to us, and among the most famous of the sky. And that was observed through the Alma telescope at ESO. Activities such as these, like the ones we see on our Sun, in red giants represent a surprise for astronomers.
A giant flare on the surface of Mira, a red giant closest to us, and among the most famous of the sky. And ‘that observed through the Alma telescope at ESO. Activities such as these, like the ones we see on our Sun, in red giants represent a surprise for astronomers. But the discovery could help explain how the winds from giant stars contribute to the ecosystem of our galaxy.
Thanks to its “view” acute, the Alma telescope has allowed a detailed observation of the star Mira A and Mira B, making it possible to obtain details of the surface of Mira A.
Credit: Katja Lindblom, CC BY-NC-ND 4.0
“The view of Alma is so acute that we can begin to see the details on the surface of the star. Part of the stellar surface is not only very bright but also varies in brightness, “says Wouter Vlemmings, astronomer at Chalmers University of Technology, who led the research team whose results were recently published in the journal Astronomy & Astrophysics.
Red giants like Mira A are essential components of the ecosystem of our galaxy. As they approach the end of their existence they lose their outer layers in the form of winds. These winds carry heavy elements into space where they can form new stars and planets. Most of the carbon, oxygen and nitrogen in our bodies was formed in stars and redistributed by winds.
Mira is known for centuries as one of the most famous variable stars in the sky and is located 420 light years away in the constellation Cetus. It is a binary system, consisting of two stars of about the same mass of the sun: the first is a dense, hot, white dwarf while its companion is a fresh, red giant, which orbit between them at a distance as to that average between Pluto and the Sun
“Mira is a key to understanding how stars like our sun reach the end of their lives and what difference it makes for a star elderly have a close companion,” says Sofia Ramstedt, astronomer at the University of Uppsala and co- author of the research.
The Sun, our nearest star, shows activity powered by magnetic fields, and this activity, sometimes in the form of solar storms, pushes the particles that make up the solar wind, which in turn can create auroras on Earth.
“To see a flare of Mira A suggests that magnetic fields play a role in the winds produced by red giants,” continues Wouter Vlemmings that concludes: “Alma showed us, for the first time, details of the surface of Mira. Now we can begin to discover the giant red closest to us in observing a detail previously impossible. “