Recent studies suggest that the universe will continue expanding and pick up speed over time. Because the universe is expanding the farther back astronomers look in time. Astronomers make regular searches of other galaxies for supernovae, the needed very large telescopes becaux the galaxies are distant and the supernovae so faint. Exploding stars represent the most significant stage of stellar evolution, supernovae are the explosive deaths of stars. The Universe is born from the Big-Bang 10 or 15 billion years ago and the solarsystem 4.6 billion years back in time.
Stars exist only in galaxies .
There are 100 billion galaxies in the Universe and maybe more . The Sun 864.000 miles in diameter is only an average star in size . It is situated three- quarters of the distance from the centre to the edge of the galaxy' s spiral arms . The galaxy M 31 in the constellation Andromeda, 2.2 million light -years away is similar to the Milky Way in appearance . Because the universe is expanding, the further back astronomers look in time .