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How would I find the distance of a star in parsecs and light years if parallax is known? For example, Sirius, the brightest star in the sky, has a parallax of 0.379 arcsec. What is its distance in parsecs? In light years?

Answer 1

Layla Anderson

The distance to the star #= 1/.379=2.638# parsecs.

#1# parsec #= 3.26# light years

So, the distance to the star:

#3.26*2.638= 8.6# light years

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Answer 2

John Alexander

Using the formula distance (in parsecs) = 1 / parallax angle (in arcseconds), one can calculate the distance in parsecs to be about 2.64 parsecs for Sirius, which has a parallax of 0.379 arcsec. To calculate the distance in light years, one can use the formula distance (in light years) = distance (in parsecs) × 3.262, which gives the distance as about 8.60 light years.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.