Astronomers were able to photograph a solar eruption June 7 that could lead to a better understanding of how young stars grow. The solar eruption led to tons of plasma being hurled into space.
The solar eruption was captured by NASA's Solar Dynamics Observatory. In the June 7 eruption on the Sun, astronomers were able to witness eruptions of plasma on the star’s surface. The incredibly hot plasma, reaching temperatures of 18,000 degrees Fahrenheit, can’t escape the Sun’s atmosphere and soon plummets back to the star’s surface. As the plasma crashes back to the surface, the solar plasma can reach temperatures of 2 million degrees Fahrenheit.
The plasma’s descent is a source of interest for the astronomers as it is similar to how young stars accumulate matter. As the Sun erupts, it sends plasma out from its surface to its atmosphere, but the plasma cannot escape due to gravity, and, as it returns to the surface, it speeds up, reaching a speed of 900,000 miles per hour. The high speeds cause the plasma to heat up.
According to the press release from the Harvard-Smithsonian Center for Astrophysics, or CfA, young stars accumulate matter in a similar manner. A young star’s gravity will pull in nearby dust and gas through a process called accretion. The consumed matter is pulled into the surface of the star and accelerates, much like plasma after a solar eruption.
Paola Testa, an astronomer from CfA, said in the release, “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.”
As the plasma accelerates, it becomes two to five times brighter in the ultraviolet spectrum. Previous theories about how to measure how fast a young star is growing could not agree on which spectrum to measure brightness. Astronomers observing how much matter a star is accumulating could measure growth because the matter is giving off light, but measuring it via the X-ray spectrum produced lower estimates than observations in the optical or ultraviolet spectrums, the press release notes.
The plasma’s return to the Sun’s surface gave astronomers the data necessary to determine the ultraviolet spectrum should be used to determine how fast a star is growing. According to the astronomers, the plasma’s increase in brightness in the ultraviolet spectrum was independent of the surrounding atmosphere. Researchers could test out this theory on young stars to determine how fast they are growing as well as what material they are consuming.