Studying the sun as a star to understand stellar flares and exoplanets — ScienceDaily

New research shows that sunspots and other active regions can change the overall solar emissions. The sunspots cause some emissions to dim and others to brighten; the timing of the changes also varies between different types of emissions. This knowledge will help astronomers characterize the conditions of stars, which has important implications for finding exoplanets around those stars.

An international research team led by Shin Toriumi at the Japan Aerospace Exploration Agency added up the different types of emissions observed by a fleet of satellites including “Hinode” and the “Solar Dynamics Observatory” to see what the Sun would look like if observed from far away as a single dot of light like other stars.

The team investigated how features like sunspots change the overall picture. They found that when a sunspot is near the middle of the side of the Sun facing us, it causes the total amount of visible

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Largest ever sample of super flares — ScienceDaily

Ultraviolet light from giant stellar flares can destroy a planet’s habitability. New research from the University of North Carolina at Chapel Hill will help astrobiologists understand how much radiation planets experience during super flares and whether life could exist on worlds beyond our solar system.

Super flares are bursts of energy that are 10 to 1,000 times larger than the biggest flares from the Earth’s sun. These flares can bathe a planet in an amount of ultraviolet light huge enough to doom the chances of life surviving there.

Researchers from UNC-Chapel Hill have for the first time measured the temperature of a large sample of super flares from stars, and the flares’ likely ultraviolet emissions. Their findings, published Oct. 5 ahead of print in Astrophysical Journal, will allow researchers to put limits on the habitability of planets that are targets of upcoming planet-finding missions.

“We found planets orbiting young

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Can ripples on the sun help predict solar flares? Scientists analyze sunquakes to pinpoint flare energy source, perhaps predict flare severity — ScienceDaily

Solar flares are violent explosions on the sun that fling out high-energy charged particles, sometimes toward Earth, where they disrupt communications and endanger satellites and astronauts.

But as scientists discovered in 1996, flares can also create seismic activity — sunquakes — releasing impulsive acoustic waves that penetrate deep into the sun’s interior.

While the relationship between solar flares and sunquakes is still a mystery, new findings suggest that these “acoustic transients” — and the surface ripples they generate — can tell us a lot about flares and may someday help us forecast their size and severity.

A team of physicists from the United States, Colombia and Australia has found that part of the acoustic energy released from a flare in 2011 emanated from about 1,000 kilometers beneath the solar surface — the photosphere — and, thus, far beneath the solar flare that triggered the quake.

The results, published Sept. 21

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