"My Favorite Enigma": Przybylski's Star

Within the Centaurus constellation you'll find the Alpha Centauri group, three stars that make up our closest neighboring star system. But also hiding inside this southern sky constellation, just beyond what our eyes can see, is a truly weird star.

Przybylski's Star, or HD 101065, is about four times the mass of the sun. Stars are fusion engines, creating heavier elements inside their cauldrons, but Przybylski's Star is cooking up the kinds of elements we don't normally see in stars—including uranium. (The Sun, like many stars, doesn't typically fuse anything heavier than nickel, which is number 28 on the periodic table.) In fact, this star seems to form only heavier elements, the kind of stuff seen in violent events like supernovae.

Jason Wright, an astrophysicist who also studies astrobiology at Penn State, called the star his "favorite astrophysical enigma" in a blog post. He says most of these elements have short half-lives, so something may be replenishing them. Searches for a small pulsar have failed, but it could be that the star cooked up super heavy elements that are decaying into ones never found on Earth.

Or maybe it's aliens dumping their trash into the star. (We just have to move past every other possible solution first.)