Solar Splashdowns Provide Insight Into Evolution of Young Stars

NASA's Solar Dynamics Observatory has captured a dramatic event that offers new insights into the evolution of young stars.

NASA's SDO captured an eruption on the Sun on June &, 2011 that blasted tons of hot plasma into the space. Some of that plasma splashed back on to the Sun sparking bright flashes of ultraviolet rays during that process. This phenomenon, might explain how young stars are formed by sucking up nearby gas, say scientists.

SDO constantly monitors the sun providing images with better HD resolution. Researchers at the Harvard-Smithsonian Center for Astrophysics (CfA) designed and developed the Atmospheric Imaging Assembly instrument of SDO. With the help of these images the researchers are able to explain about the evolution of young stars.

"We're getting beautiful observations of the Sun. And we get such high spatial resolution and high cadence that we can see things that weren't obvious before," CfA astronomer Paola Testa said in a press statement.

On observing the movies of the 7^th June eruption, the researchers noticed dark filaments of gas being blasted outward from the Sun's lower right. Against the Sun's bright surface, the solar plasma looked dark but when the temperature reaches 18,000 degree Fahrenheit, the solar plasma glows. When the splashes of plasma strike the Sun's surface another time they heat up by a factor of 100 to a temperature of almost 2 million degrees F. Due to this, the spots lighten by a factor of 2-5 within minutes.

The release of such tremendous energy occurs due to the result of falling drops of plasma that are travelling at high speeds of 900,000 miles per hour (400 km/sec), that is similar  to the speeds attained by material declining onto infant stars as they mature by means of accretion. 

"We often study young stars to learn about our Sun when it was an 'infant.' Now we're doing the reverse and studying our Sun to better understand distant stars," said Testa.

Combining the observation with computer modeling, an endless argument on how to measure the accretion rates of growing stars can be solved.

The rate at which the young star collects material is calculated by the astronomers by observing their brightness at different wavelengths of light and how the brightness alters over time. Higher estimations were achieved from optical and ultraviolet light than from X-rays.

The research team noticed that ultraviolet flashes were produced by the falling material itself and not the solar atmosphere surrounding them. Scientists predict that if the same is true for distant infant stars then they can study about the materials they are accumulating by analyzing the UV lights they emit.

Testa says that it gets easy to study about how young stars accrue material and grow, just by seeing the dark spots on the sun.