There is a star whizzing through our galaxy that astronomers believe started out in a dwarf galaxy gobbled up by the Milky Way. That's not the Methuselah Star's main claim to fame, however. Early studies put the star's age at 16 billion years. That's fine-- except the current best, most sophisticated estimate of the age of the universe has the Big Bang banging 13.8 billion years ago.
New, more detailed study of the star has dropped its age at the lower end of an age range to 13.7 billion years, but the high end is still well over 14 billion years. Further refinement is necessary. Either this star's age must be shown to fit within our current conception of the cosmos, or that conception, including much of what we think we know about extreme high energy physics, will have to change.