Astronomy with an Opera-glass: A Popular Introduction to the Study of the Starry Heavens with the Simplest of Optical InstrumentsServiss, Garrett Putman
Science
Astronomy with an Opera-glass: A Popular Introduction to the Study of the Starry Heavens with the Simplest of Optical Instruments
Serviss, Garrett Putman
Astronomy
The center of the map is the zenith, or point overhead. The reader must
now exercise his imagination a little, for it is impossible to represent
the true appearance of the concave of the heavens on flat paper. Holding
the map over your head, with the points marked East, West, North, and
South in their proper places, conceive of it as shaped like the inside
of an open umbrella, the edge all around extending clear down to the
horizon. Suppose you are facing the south, then you will see, up near
the zenith, the constellation of Leo, which can be readily recognized on
the map by six stars that mark out the figure of a sickle standing
upright on its handle. The large star in the bottom of the handle is
Regulus. Having fixed the appearance and situation of this constellation
in your mind, go out-of-doors, face the south, and try to find the
constellation in the sky. With a little application you will be sure to
succeed.
Using Leo as a basis of operations, your conquest of the sky will now
proceed more rapidly. By reference to the map you will be able to
recognize the twin stars of Gemini, southwest of the zenith and high up;
the brilliant lone star, Procyon, south of Gemini; the dazzling Sirius,
flashing low down in the southwest; Orion, with all his brilliants,
blazing in the west; red Aldebaran and the Pleiades off to his right;
and Capella, bright as a diamond, high up above Orion, toward the north.
In the southeast you will recognize the quadrilateral of Corvus, with
the remarkably white star Spica glittering east of it.
Next face the north. If you are not just sure where north is, try a
pocket-compass. This advice is by no means unnecessary, for there are
many intelligent persons who are unable to indicate true north within
many degrees, though standing on their own doorstep. Having found the
north point as near as you can, look upward about forty degrees from the
horizon, and you will see the lone twinkler called the north or pole
star. Forty degrees is a little less than half-way from the horizon to
the zenith.
By the aid of the map, again, you will be able to find, high up in the
northeast, near the zenith, the large dipper-shaped figure in Ursa
Major, and, when you have once noticed that the two stars in the outer
edge of the bowl of the Dipper point almost directly to the pole-star,
you will have an unfailing means of picking out the latter star
hereafter, when in doubt.[A] Continuing the curve of the Dipper-handle,
in the northeast, your eye will be led to a bright reddish star, which
is Arcturus, in the constellation Booetes.
[A] Let the reader remember that the distance between the two
stars in the brim of the bowl of the Dipper is about ten
degrees, and he will have a measuring-stick that he can
apply in estimating other distances in the heavens.
Public-domain text, read in full here on John Shaqi.
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