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The Question
(Submitted April 10, 1997)
Is Polaris bigger or smaller than our Sun? (I'm 8 years of age).
The Answer
Polaris
("The North Star") is a unique star because it is directly
overhead at the North Pole. This makes it very useful, because it is
always in the North. Not only that, but the farther North you go, the
higher up in the sky it appears. If you are ever lost at sea, you can
always tell which way is north, and what your latitude is, just by
looking at Polaris.
On the other hand, as a star goes it is quite typical. It is not the brightest star in
the sky, but plenty bright enough to see at night.
As far as how it compares to the Sun (which is type G2 V), it is only slightly hotter, but much
brighter, larger and heavier than the Sun. Here is the relevant information
on it and stars of similar type (F8 Ib).
Temperature = about the same as the Sun
Wattage = about 10,000 x brighter than the Sun
[Astronomers call this "luminosity"]
Our Sun gives off: 400,000,000,000,000,000,000,000,000 Watts
Size = 100 x our Sun
[in Radius, so 1,000,000 times bigger in volume]
Our Sun is 100 x the size of the Earth
Mass = 10 x our Sun
our Sun is 300,000 times heavier than the Earth
Thank you for your question.
Sincerely,
Jonathan Keohane and Mike Arida
-- for Imagine the Universe!
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