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Sharp-Eyed Alma Spots A Flare On Famous Red Giant Star


Artist’s impression of a giant flare on the surface of red giant Mira A. Credit: Katja Lindblom, CC BY-NC-ND 4.0

Artist’s impression of a giant flare on the surface of red giant Mira A. Credit: Katja Lindblom, CC BY-NC-ND 4.0

Super-sharp observations with the telescope Alma have revealed what seems to be a gigantic flare on the surface of Mira, one of the closest and most famous red giant stars in the sky. Activity like this in red giants – similar to what we see in the Sun – comes as a surprise to astronomers. The discovery could help explain how winds from giant stars make their contribution to our galaxy’s ecosystem.

New observations with Alma have given astronomers their sharpest ever view of the famous double star Mira. The images clearly show the two stars in the system, Mira A and Mira B, but that’s not all. For the first time ever at millimetre wavelengths, they reveal details on the surface of Mira A.

“Alma’s vision is so sharp that we can begin to see details on the surface of the star. Part of the stellar surface is not just extremely bright, it also varies in brightness. This must be a giant flare, and we think it’s related to a flare which X-ray telescopes observed some years ago”, says Wouter Vlemmings, astronomer at Chalmers, who led the team.

Link To Full Story

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New Method Detects Emerging Sunspots Inside the Sun

August 19, 2011 Leave a comment

New Method Detects Emerging Sunspots Inside the Sun

A full disk image of the Sun showing the sunspot group in AR11158 after emergence, observed by SDO/HMI. Courtesy of NASA/SDO and the HMI science teams.

The first clear detection of emerging sunspot regions prior to any indication of the region in magnetograms was published in Science on 19 August 2011.

Sunspots, dark features in the solar photosphere with strong magnetic field, have been observed for more than 400 years. They are the most visible components of regions where solar flares and coronal mass ejections (CMEs) occur, and these eruptive events may cause power outages and interruptions of telecommunication and navigation services on the Earth. Although it is widely believed that sunspot regions are generated in the deep solar interior, the detection of these regions before they emerge from the convection zone into the photosphere has remained undetected until now.

Full Story: http://hmi.stanford.edu/Press/18Aug2011/