The emission nebula known as M20, the Trifid Nebula in Sagittarius, is listed in catalogs as having an angular size of about 20 arc minutes and a distance of 2200 light-years from Earth. How large is it physically?

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     about 13 light-years, or about 4 parsecs across
      It is impossible to determine this from the information given.
      about 100 light-years, or about 30 parsecs across
      about 4 light-years, or about 1.2 parsecs across
      about 0.5 light-years, or about 0.15 parsecs across
asked Sep 20, 2012 in Astronomy by anonymous
    

1 Answer

0 votes
about 13 light-years, or about 4 parsecs across
answered Sep 22, 2012 by SkyStar ~Expert~ (2,855 points)



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