Check out this video, made from images taken by NASA's Solar Dynamic Observatory. Notice that weird object the size of Jupiter apparently connected to the Sun. Is it the Death Star refueling? Galactus' ship? An alien star dreadnought? What is it?
The answer is simple. According to Alex Young, one of the scientists at NASA Goddard Space Center's heliophysics department, it is just a "coronal cavity associated with a filament." Commenting to Gizmodo, Alex said that his phenomena is now commonly observed thanks to SDO:
[The sphere] is called a coronal cavity and it is part of a structure called a filament—or prominence when observed off the edge of the Sun.
Sun's filaments look dark while observed at certain light wavelengths because they are cooler than the surrounding material. But while these phenomena are common, he told us that this video is quite special:
The conditions were right—viewing angle, combination of image filters, etc.—so it seemed exceptional. It really isn't but it looks interesting. The one thing that is interesting and added to the combination of factors is that it is about to erupt just after the period in the original video.
You can see Alex's full explanation in the video to the left. And remember kids: these images are published constantly in the internet, all of them available to the public and watched by hundreds of scientists every day. If one day there's a star destroyer or a Death Star next to the Sun, you can bet your life that you will learn about it from NASA, ESA or any other space agency or astronomy organization in the world.