Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What do you make of this?

  1. May 7, 2003 #1
    It's a galaxy in the form of a torus and the gas, dust and star forming regions lie on the surface of the torus.

    http://hyperphoto.photoloft.com/view/exportImage.asp?s=cano&i=10620506&w=640&h=800 [Broken]
    Last edited by a moderator: May 1, 2017
  2. jcsd
  3. May 7, 2003 #2
    I think it is really fascinating! I thought a taurus was a bull?
    Why is it shaped the way it is?
  4. May 7, 2003 #3
    a torus is a bulge or large swell. it is very weird though.
  5. May 7, 2003 #4


    User Avatar
    Science Advisor
    Gold Member
    Dearly Missed

    Hoag's object is a ring galaxy---several examples of ring galaxies are known----there is another in the picture

    blob of old (reddish) stars in the middle
    a ring of young blue stars---and star formation

    one theory is it used to be a barred spiral and something
    knocked the bar out

    There is a ring galaxy called Cartwheel which has evidence of its center having been crashed thru by another small galaxy which is visible leaving the scene and is already 250,000 LY away.

    There's a theory that a collision at the center could cause an expanding ripple of star formation out like a rock going thru the surface of a pond.
    Last edited by a moderator: May 1, 2017
  6. May 7, 2003 #5


    User Avatar
    Science Advisor

    Greetings !

    Yeah, I've seen it some time ago in the news.
    Can't remember if they said why does it look
    like that, but I suppose that statisticly if you
    look at enough galaxies you'd expect one to
    look like that. Anyway, what's that in the middle ?
    A quasar ? Just some star that was in the way ?
    Also, it's not exactly a torus because the
    matter seems evenly ditributed, not in a curved
    empty cylindrical form.

    Live long and prosper.
  7. May 7, 2003 #6


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    A torus is actually like a donut.
  8. May 8, 2003 #7
    oh well, i was using the definition of a torus in anatomy, thought they would be the same.
  9. May 8, 2003 #8
    Re: Re: What do you make of this?

    The yellow nucleus is just a bunch of older stars. The best explanation of the formation is a galaxy passed nearby, stripping it somewhat.

    Cartwheel galaxy-
    http://ftp.seds.org/pub/images/hst/Cartwheel.jpg [Broken]

    Another picture of Hoag Object, more realistic of what a person would see, I thought it was interesting-
    Last edited by a moderator: May 1, 2017
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook