Astronomers aren't being poetic when they say this star is a diamond. Scientists have identified what is possibly the coldest white dwarf ever detected. In fact, this dim stellar corpse is so cold that its carbon has crystallized, effectively forming a diamond the size of Earth, astronomers said. "It's a really remarkable object," study leader David Kaplan, a professor at the University of Wisconsin-Milwaukee, said in a statement from the National Radio Astronomy Observatory (NRAO). "These things should be out there, but because they are so dim they are very hard to find." More via Space.com.