Are the stars that we see in constellations within the Milky Way galaxy?

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Discussion Overview

The discussion revolves around whether the stars visible in constellations are located within the Milky Way galaxy. Participants explore the visibility of stars and galaxies, the distances of stars, and the nature of celestial objects that may or may not be included in constellations.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants assert that the stars seen in constellations are indeed within the Milky Way galaxy, suggesting that individual stars are typically too dim to be seen from outside the galaxy.
  • Others mention that while individual stars are generally within the Milky Way, there are visible galaxies like Andromeda that can be seen with the naked eye, but not individual stars from those galaxies.
  • A participant proposes that the farthest naked-eye visible star is approximately 4000 light years away, indicating that stars in constellations can be quite distant yet still within the Milky Way.
  • There is a discussion about specific celestial objects, such as Omega Centauri, which is a star cluster and not a single star, and its classification in relation to constellations.
  • Some participants highlight that certain non-stellar objects, like the Orion Nebula, are included in the outlines of constellations, but they do not represent stars.
  • Several participants provide lists of the brightest stars and their distances, noting that many of these stars are relatively close, with some being over 1000 light years away.
  • One participant speculates on the distribution of star brightness and its relation to mathematical concepts, suggesting a potential homework problem based on this observation.
  • A later post introduces findings about distant stars in the Milky Way's halo, noting that some stars are over a million light years away, which raises questions about the definition of the galaxy's outer limits.

Areas of Agreement / Disagreement

Participants generally agree that the stars in constellations are within the Milky Way, but there are competing views regarding the visibility of other celestial objects and the classification of certain non-stellar entities. The discussion remains unresolved regarding the implications of distant stars and their relation to the Milky Way's boundaries.

Contextual Notes

Some claims about distances and classifications depend on specific definitions and observational limitations. The discussion includes various assumptions about visibility and the nature of celestial objects.

  • #31
Vanadium 50 said:
At one end you need very bright stars to see them, and they are rare, and at the other end you need dim stars to be very close and they are rare too. (Trivia question: how many stars are visible to the naked eye and are dimmer than the sun?)
That depends on the magnitude threshold your eye and sky allow.
Adopting +6,00:
  1. ε Eridani +3,73 +6,19
  2. 61 Cygni +4,7 +7,5 (Not resolved by naked eye but combined magnitude is not commonly quoted. Simple mathematics but some taking of logarithms, so I rounded)
  3. ε Indi +4,69 +6,89
  4. τ Ceti +3,49 +5,68 the brightest of these, about nr. 280 of all stars
  5. ο2 Eridani +4,43 +5,93
  6. 70 Ophiuchi +4,00 +5,66
  7. σ Draconis +4,67 +5,87
  8. 33 Librae +5,64 +6,79
  9. 36 Ophiuchi +4,3 +6,2 (again AB combined magnitude rounded)
  10. 279 Sagittarii +5,31 +6,41
  11. e Eridani +4,26 +5,35
  12. Gliese 892 +5,57 +6,49
  13. ξ Bootis +4,7 +5,59
  14. Gliese 105 +5,79 +6,50
  15. 96 Piscium +5,74 +6,37
  16. 107 Piscium +5,24 +5,86
  17. μ Cassiopeiae +5,17 +5,78
  18. p Eridani +5,0 +6,25
  19. 61 Virginis +4,74 +5,09
  20. 41 Arae +5,55 +5,83
  21. 5 Capricorni +5,73 +6,00
  22. κ1 Ceti +4,84 +5,16
  23. 66 Centauri +4,89 +5,06
  24. 61 Ursae Majoris +5,31 +5,41
  25. 289 Hydrae +5,97 +6,06
  26. 12 Ophiuchi +5,77 +5,82
  27. Gliese 75 +5,63 +5,61
  28. α Mensae +5,09 +5,03 the dimmest lucida and the only lucida to be dimmer than Sun
  29. 54 Piscium +5,88 +5,65
  30. 11 Leonis Minoris +5,40 +5,16
  31. ζ1 Reticuli +5,52 +5,11. Note that ζ2, resolved by naked eye, is so close to Sun in brightness that sources differ on which is the brighter
  32. 85 Pegasi +5,81 +5,34
  33. ρ1 Cancri +5,96 +5,47
  34. 285 Puppis +5,95 +5,45
  35. 24 Virginis +5,54 +4,99
  36. 86 Sagittarii +5,85 +5,28
  37. 58 Eridani +5,63 +5,01
  38. π1 Ursae Majoris +5,63 +4,86
  39. ψ Serpentis +5,86 +5,03
  40. Gliese 1021 +5,80 +4,93
There is a possibility of a few more just beyond 15 pc, but likely not many.
 
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  • #32
Ken G said:
So it's really a remarkable coincidence that the curve looks so perfect, given the statistics.
I think it's just a happy coincidence.
Expanding the grouping to 34 points yields a much dirtier fit.

Dirtier bell data. 2023-04-15 at 20.38.45.png

x-axis: 0.9 * ln( distance in light years )
y-axis: star count

Now if I can just figure out how to extract less than a billion data points from the Gaia database, I'll be able to make some more fancy graphs.
 
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