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The Question
(Submitted March 18, 1998)
I'm in 6th grade and studying the planets and the stars and galaxies and I
wanted to know what magnification of telescope it takes to take a picture of
other galaxies?
The Answer
Some of the closer galaxies, Andromeda in the Northern Hemisphere and
the Magellanic Clouds in the Southern for example, are visible with
the naked eye, so photographs can be taken with a 1X telescope, although
you would need to have a way to track the galaxy for a long exposure.
Far more important than the magnification is the size of the opening,
which determines how much light the telescope collects, and the quality
of the optics. Although many inexpensive telescopes try and sell
selves with magnification claims, a telescope is typically not useful
at magnifications more than 1X per mm of opening. So a 60mm refractor
is really only useful up to about 60X, although they'll sell them as
200X telescopes.
Thanks for your questions!
Eric Christian
for Ask a High-Energy Astronomer
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