Barnard's star
At seven to 12 billion years of age, Barnard's Star is considerably older than the Sun, and it might be among the oldest stars in the Milky Way galaxy. Barnard's Star rotates just once every 130 days (compared with just over 25-30 days for the Sun). In 1998 astronomers saw an intense flare, showing that Barnard's Star is a 'flare star'. Barnard's Star has the variable star designation V2500 Ophiuchi.