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How many degrees equal one hour of right ascension?

15 degrees equals one hour of right ascension.

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  1. 10 degrees
  2. 15 degrees ✔
  3. 24 degrees

Why: Right ascension divides the full 360-degree sky circle into 24 hours. Dividing 360 by 24 gives 15 degrees per hour.

Huh, didn't know that: Right ascension is measured eastward from the vernal equinox.

The dad joke
Right ascension keeps good hours because the stars hate overtime.
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References

Answer: 15 degrees. Right ascension divides the full 360-degree sky circle into 24 hours. Dividing 360 by 24 gives 15 degrees per hour.

  1. Earth and Sky openstax.org/books/astronomy-2e/pages/4-1-earth-and-sky
    Then each 15° of arc is equal to 1 hour of time.
    Checked 2026-10-10.

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