The First Generations of Stars

The very first stars that formed after the Big Bang, some 13 to 14 billion years ago, are likely to have been quite massive and extremely short-lived; no examples are expected to remain in the universe today. However, they may have left behind their “calling cards” by producing a distinctive distribution of elements recorded in the atmospheres of long-lived stars that formed just after these massive progenitors. Stars that are extremely iron poor (hyper metal-poor stars) are believed to be very old, and are thus possible candidates for second-generation stars.