Astronomers from the Harvard-Smithsonian Center for Astrophysics posit that a young suggests our Sun was a “feisty” toddler.
Astronomers have long been fascinated by the period, 4.5 billion years ago, that our solar system formed. Unfortunately, time travel has yet to be invented. However, astronomers can learn a lot about the birth of our Sun and its planets by examining young stars in our galaxy. This study reveals that our Sun was both active and feisty as a toddler, developing it fits and stars while belching out bursts of X-rays.
According to Nancy Brickhouse of the Harvard-Smithsonian Center for Astrophysics, TW Hydrae offers a plethora of information about what exactly happened to our Sun when it was younger.
Brickhouse and her fellow astronomers came to this conclusion by examining the young star TW Hydrae, situated approximately 190 light-years from Earth in the southern constellation Hydra the Water Snake. According to the astronomers, TW Hydrae is a type K star weighing approximately 80 percent as much as our Sun. The young star is still amassing gas from a surrounding disk of material.
TW Hydrae develops by “eating” gas from the disk. However, the young star isn’t able to “eat” from it directly because the disk doesn’t extend all the way to the star’s surface. Instead, infalling gas is sent along magnetic field lines to the star’s poles.
CfA member Andrea Dupree said that the astronomers are able to observe the accretion process because they are looking directly down on one of TW Hydrae’s poles.
Infalling material hits the star, producing a shock wave and heating the amassing gas to more than 5 million degrees Fahrenheit. As the gas moves inward, it cools and its glow shifts from high-energy X-rays to optical wavelengths of light.
The astronomers combined data from NASA’s Chandra X-ray Observatory and several ground-based optical telescopes, which allowed them to study the entire accretion process for the first time.
They discovered that accretion was “clumpy” and “episodic” in creating a star. In fact, the astronomers found that the amount of material smashing into the star differed by a factor of five over the course of several days.
Some of the infalling material is blown away by a stellar wind, while some gets channeled into large loops and stellar prominences.
Though astronomers have known for some time that young stars are a lot more magnetically active than our Sun, now they are actually able to see the interaction between the star’s magnetic fields and the protoplanetary disk.
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