This is 3 books. Vulcan by Kathleen Sky. Due to a series of freak ion storms, the Neutral Zone separating the Federation from the Romulan Empire will soon shift--and the planet Arachnae will fall entirely within Romulan space. Our mission: seek out intelligent life there and, if it exists, offer full Federation protection. Planet of Judgement by Joe Haldeman. On a routine mission to Starfleet Academy, the sensors for the USS Enterprise detect the presence of a rogue planet in space, orbited by a sun no larger that a pea, a circumstance impossible to explain by any known scientific law. Assuming the star to be an artificial construct, a landing party is dispatched to the planet's surface, and there becomes trapped. Corona by Greg Bear. An awesome force of protostars known as Corona has taken control of a stranded team of Vulcan scientists. The Starship Enterprise* has come on a rescue mission, with a female reporter and a new computer that can override Kirk's command.