The Oceans Between Stars

It is Earth year 2223, but the Earth, along with the entire solar system, is gone.
Liam and Phoebe, having barely escaped our exploding sun with their lives, are in stasis for the decade-long journey to the rogue planet Delphi, where they hope to meet up with the rest of the human refugees, find help for their injured parents, and pass along the devastating things they discovered on Mars: that someone destroyed their world intentionally, and that that someone might still be after them, trying to finish the job.
Phoebe is carrying her own dark secret. One that finds her waking up secretly at various points in their journey, changing their path through space. One that will decide the fate of the human race, and many more besides. One that, very soon, she must reveal to Liam, whether he's ready for the truth or not.