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

Stars in the same constellation

  1. Jan 19, 2017 #1
    Do any of the constellations have two or more stars in them that happen to actually be close to each other (10 light years or less)? This excludes binary star systems of course.
     
  2. jcsd
  3. Jan 19, 2017 #2

    phyzguy

    User Avatar
    Science Advisor

    Yes, definitely. Many stars are associated in clusters of various sizes. For example, the head of the bull in the constellation Taurus is mainly made up of stars in the Hyades cluster, which has many stars in about a 10 light-year radius. The Pleiades cluster has ~1000 stars in a radius of about 8 light-years.
     
  4. Jan 19, 2017 #3

    davenn

    User Avatar
    Science Advisor
    Gold Member

    That is the only one I'm aware of

    doesn't count ... it isn't a constellation



    so in general, the answer is no


    Dave
     
  5. Jan 19, 2017 #4

    phyzguy

    User Avatar
    Science Advisor

    Not to nitpick, but the OP said, "Do any of the constellations have two or more stars in them..." Are you saying the Pleiades is not in a constellation? Every point on the sky is in some constellation.

    There are other examples. Most of the stars in Ursa Major are part of the Ursa Major moving group, a nearby cluster where many of the members are within 10 light-years of each other. For example ε Ursa Majoris and δ Ursa Majoris are only about 8 light-years apart. I'm sure I could find other examples.

    Clearly the answer to the OP's question is yes, not no.
     
  6. Jan 19, 2017 #5

    davenn

    User Avatar
    Science Advisor
    Gold Member

    No, I didn't say that

    The Pleiades is a star cluster ... NOT a constellation

    it's within the boundary of the Taurus constellation. And that goes for every other star cluster and other object in the sky
    a random one ... M44 cluster in Cancer is in that constellation but it's stars are not PART of the actual constellation as originally described

    I have seen argument that the Pleiades may be actually be a part of the actual constellation of Taurus ... I can accept that :smile:
    It would be the only constellation that has, not one, but two, open clusters whose stars and actually part of the constellation makeup

    upload_2017-1-20_13-17-14.png


    more correctly, Every star in the sky is within the boundary of a given constellation

    But don't forget that when the constellations were named was long before telescopes and other optical aides.
    So for the casual observer back then and now, it was the brighter stars that made up the constellation outlines


    D
     
  7. Jan 20, 2017 #6
    Sorry, I suppose I should have been more clear. I was referring the the major stars visible to the naked eye which are part of the shapes of the 88 modern constellations.
     
  8. Jan 20, 2017 #7

    davenn

    User Avatar
    Science Advisor
    Gold Member

    no problems ... that's the way I understood your question :smile:

    was your question answered or do you need more info ?


    Dave
     
  9. Jan 20, 2017 #8
    I believe it's been answered, thanks. Except for two stars in the constellation of Taurus, there are none.
     
  10. Jan 20, 2017 #9

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Who said that? I challenge you to find that in this thread anywhere.
     
  11. Jan 20, 2017 #10

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    That drawing looks more like Taurus the Bunny than Taurus the Bull. Where did you find it?
     
  12. Jan 20, 2017 #11

    davenn

    User Avatar
    Science Advisor
    Gold Member

    hahaha it's the skylore art that's in the Stellarium astro program

    ohhh and upside down as it's my view from the southern hemisphere


    D
     
  13. Jan 20, 2017 #12

    phyzguy

    User Avatar
    Science Advisor

    How did you conclude that??? What about the two I pointed out in Ursa Major? This was after about 5 minutes of searching. You've looked through all 88 constellations and confirmed there are no more?
     
  14. Jan 20, 2017 #13

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    While the angular spread is a bit wide, four of the brightest stars in the big dipper [UMa] are very nearly the exact same distance from earth; Alioth, Mezak, Mizar and Phedca all between 77- 80 light years. The same is true for Rasalhague and Sabik in Ophiuchus at 46-48 light years. And 2 of the 10 brightest stars in the night sky, Sirius and Procyon, are among our nearest neighbors at 8.6 and 11 light years, although technically in adjacent constellations.
     
    Last edited: Jan 20, 2017
  15. Jan 21, 2017 #14

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    The average constellation extends about 12 degrees from its center point. That means any pair of stars closer than 10 light years away and more than about 50 light years out has a good chance of ending up in the same constellation.
     
  16. Jan 21, 2017 #15

    davenn

    User Avatar
    Science Advisor
    Gold Member

    you do understand he is talking about distance from each other .... not common distance from earth ?
     
  17. Jan 21, 2017 #16

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Yes. Two stars that are 10 light years from each other AND at least 50 light years from earth will have a good chance of being in the same constellation. That's just geometry.
     
  18. Jan 22, 2017 #17

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    Yes, I realize that and already acknowledged the angular separation of the stars I listed puts them at a distance from each other that likely exceeds 10 light years. That does not change the fact they are within 10 light yeas of the same distance from earth. The stars in UMa mentioned belong to a cluster known as the UMa moving group and are no more than 30 light years distant from their nearest neighbor in that group.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted