1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Light orbiting BH

  1. Aug 4, 2004 #1

    turin

    User Avatar
    Homework Helper

    I just wanted a quick affirmation. Can light orbit a black hole? That is, can light remain between two well-defined distances from the event horizon (or at a single well-defined distance, which I am leaning towards) indefinitely?
     
  2. jcsd
  3. Aug 4, 2004 #2

    DW

    User Avatar

    For a Schwarzschild hole it can orbit at the photon sphere [tex]r_{ps}[/tex] which is at
    [tex]r_{ps} = \frac{3GM}{c^{2}}[/tex].
    It is an unstable orbit though.
     
  4. Aug 4, 2004 #3

    turin

    User Avatar
    Homework Helper

    Thanks, DW. That's exactly what I was looking for.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?