... Star Atlas . ... Hubble finds that puny stars pack a big punch . ... These stars, which are smaller than the Sun, can unleash powerful eruptions called flares that may release the energy of more than 100 million atomic bombs. ... Osten and her team, including Adam Kowalski of the University of Washington in Seattle, found that the red dwarf stars flared about 15 times less frequently than in previous surveys, which observed younger and less massive stars. ... A few stars produced multiple flares. ...