This image is way too cool! It looks like it's from a page of a comic book or graphic novel, but it wasn't drawn by an artist. A supercomputer made this simulation of a sunspot in striking scientific detail.
Here's a little trivia:
Did you know that most sunspots are bigger than Earth? Sunspots can be up to several times larger than the diameter of the Earth. And sunspots are really "cool", cooler than the surrounding region of the Sun's surface.
Now this pretty model of a sunspot may be similar to the spots on the surface of other stars. And so we call them Starspots.
Starspots may be pretty but it's not really appealing to planet-hunters. The reason is that starspots may interfere with the transit method of finding planets. It may even distort the measurement of the exoplanet's true size.
The transit method relies on measuring the slight dimming of starlight as the planet passes across our field of view of the star. But huge starspots of an active star may be mis-interpreted as a planet since it also dims the light as the spots move across the star, often in the same direction as the planets.
That is why planet-hunters hoping to bag a new exoplanet discovery are wary of starspots when trying to interpret their data. They use all sorts of noise-reduction techniques to normalize the figures, and avoid the confusion.
But here's the interesting part: because of starspots, known exoplanets are given a chance to help astronomers study the surface of other stars. Irregular dips, bumps and spikes along the lightcurves may be attributed to starspots (if proven that it was not another planet that caused the bumps). Thus, known exoplanets then allow astronomers to approximate the size of the starspot, it's speed of movement, and it's rotational period around the parent star.
And consequently, the spots tell a lot about it's parent star such as the "solar-like" activity cycle, and the star's speed of rotation.
And there you have it! The unexpected relationship between Starspots and Exoplanets is actually a bitter-sweet engagement that poses a challenge to planet-hunters at first, but eventually brings us greater knowledge of exoplanetary systems in the long run.