CAPE CANAVERAL, Fla.—NASA’s new space telescope has captured its first starlight and even taken a selfie of its giant, gold mirror. All 18 segments of the primary mirror on the James Webb Space Telescope seem to be working properly 1.5 months into the mission, officials said Friday. The telescope’s first target was a bright star 258 light-years away in the constellation Ursa Major. “That was just a real wow moment,” said Marshall Perrin of the Space Telescope Science Institute in Baltimore. Over the next few months, the hexagonal mirror segments—each the size of a coffee table—will be aligned and focused as one, allowing science observations to begin by the end of June. The $10 billion infrared observatory—considered the successor to the aging Hubble Space Telescope—will seek light from the first stars and galaxies that formed in the universe nearly 14 billion years ago. It will also examine the atmospheres of …