Stars and Constellations
Name: kristina matarazzo
Date: 1993 - 1999
Why do stars always stay in the same place. For example, I can always
find the constellations. Why don't the stars change into other constellations?
Stars seem to stay in the same place for a long time, long compared to
our lifetime. This happens because of the large distance that separates us from
the stars. We can observe only changes in the angular position of stars. An
object at distance D will appear to move by one degree across the sky if it move s a distance D/60.
For a star at a distance of few light years from us, this displacement is also
of the order of a light year. Given the average velocity of stars, this distance
will be covered in a few thousand years
So these two reasons contribute, large distance to stars and small relative
velocity of stars, in making stars appear stationary.
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Update: June 2012