So it looks like the sun is a bit rounder than we thought it was, but it's also a bit flatter too. Weird, huh? Well, when we say flatter, we mean scientists say it's a bit more squashed, making the star a bit wider at the middle than at its poles.
Yesterday's findings raise quite a few more mysteries about the star, mostly regarding to what the heck actually goes on inside of it. The sun goes through a rather rhythmic change in activity, and during the approximately 11-year-long solar cycles, the number of sunspots on the surface rise and fall in dramatic numbers. But until now, researchers thought that the shape of the sun changed along with this cycle. For over 50 years, researchers have found it a massive challenge to accurately measure the sun's shape.
Using data from NASA's Solar Dynamics Observatory, researchers have managed to measure the solar shape over a two-year period, from 2010 to 2012, during which the sun evolved from a minimum of sunspot activity to a maximum. Another factor to help identify the sun's shape is that the Observatory is located in space, which helps it avoid the Earth's atmosphere which would distort measurements through its influence.
Suprisingly, Jeffrey Kuhn and his colleagues found that the sun's slightly flattened shape, with a wide equator and shorter distance between its poles, is quite stable and pretty much unaffected by the solar cycle. This leads to suggestions that the shape of the sun "really is controlled by fundamental properties of the star, and not so much by the sun's perhaps superficial magnetism, which is highly variable," Kuhn said.
Still, despite the flatness depicted from their measurements, they have also found that the sun is still rounder than theory had predicted. "The peculiar fact that the sun is slightly too round to agree with our understanding of its rotation is also an important clue in a longstanding mystery," Kuhn said. "The fact that it is too round means that there are other forces at work making this round shape. We've probably misunderstood how the gas turbulence in the sun works, or how the sun organizes the magnetism that we can only see at the surface. Finding problems in our theories is always more exciting than not, since this is the only way we learn more."
I'm trying to picture the sun's shape, and all I can image is a slightly squashed, yet rounded orange. Can anyone help with that? [Space on NBCNews.com]
Image credit: Sun from Shutterstock