• Question: whats the brightest star?

    Asked by Kyra2002 to Helen, Hugh, Julian on 20 Nov 2014.
    • Photo: Hugh Osborn

      Hugh Osborn answered on 20 Nov 2014:

      The bigger a star is, the brighter it becomes. This is because the force of gravity is stronger, compressing the centre of the star more, causing nuclear fusion (the reaction that powers all stars) to go much quicker.

      One of the biggest (and therefore brightest) stars we have ever found is R136a1 (not a great name, I know). That star is in our neighboring galaxy, the Large Magellanic Cloud, and is 260 times heavier than the sun and is more than 8.7 MILLION brighter. Pretty incredible.

      The brightests stars also live the shortest lives, so we expect this one to go bang in a supernova in the next few million years.

    • Photo: Julian Onions

      Julian Onions answered on 20 Nov 2014:

      When a star goes supernova, which only happens to very big stars, they become brighter still for a few months, and can outshine all the other stars in the galaxy for that time!

    • Photo: Helen Johnson

      Helen Johnson answered on 21 Nov 2014:

      Ok so the boys have got this question pretty much sorted, but I’ll just add a few things 🙂
      R136a1 might be the brightest star ever found, but it’s so far away that we can’t really see it so clearly here. The brightest star in our sky is called Sirius (actually loads of stars have names like Harry Potter characters, e.g. Bellatrix and Regulus!). It’s name means ‘glowing’ in Greek and you can find it just down a little further than Orion.
      We think that the reddish star in Orion, Betelgeuse, will actually go supernova any time now – and when that happens it’ll likely outshine everything else in the sky!

Comments