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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.


Jonathan Keohane and Mike Arida

-- for Imagine the Universe!

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