This method is fundamentally flawed. What happens when two stars have the same distance? Why are you calculating spherical co-ordinates with a cartesian distance? Are you aware that RA (Right Ascension) is measured in hours, (from 0-24), not degrees?

(Updated: Yes, [id://hardburn], technically 0h to 23h 59m 59.999999...s, but I was trying to be lazy.)

On the technical level, you are trying to index your array using a non-integer value $r2 which is much much less than one, so your calls to $foo[$sorted[$r2]] are returning $foo[$sorted[0]]. There are other stylistic issues, but this is your main technical problem.

You would do better to use a hash, as suggested by dpuu ... though for the wrong reason. Even better would be to rotate your coordinates so that your center point is at +90, as then distance becomes simple subtraction. Perhaps Astro::Coords can help?

  use Astro::Coords;

  $c = new Astro::Coords( name => "My center",
                          ra   => '05:22:56',
                          dec  => '-26:20:40.4',
                          type => 'B1950'
                          units=> 'sexagesimal');
  $t = new Astro::Coords( name => "My target",
                          ra   => '05:22:56',
                          dec  => '26:20:40.4',
                          type => 'B1950'
                          units=> 'sexagesimal');
  print $c->distance($t);
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