Pleasures of the telescope: An Illustrated Guide for Amateur Astronomers and a Popular Description of the Chief Wonders of the Heavens for General Readers — John Shaqi
Pleasures of the telescope: An Illustrated Guide for Amateur Astronomers and a Popular Description of the Chief Wonders of the Heavens for General ReadersServiss, Garrett Putman
Science
Pleasures of the telescope: An Illustrated Guide for Amateur Astronomers and a Popular Description of the Chief Wonders of the Heavens for General Readers
Having looked at alpha (Betelgeuse), the great topaz star on Orion's
right shoulder, and admired the splendor of its color, we may turn the
four-inch upon the star Sigma 795, frequently referred to by its number
as "52 Orionis." It consists of one star of the sixth and another of
sixth and a half magnitude, only 1.5" apart, p. 200 deg.. Having separated
them with a power of two hundred and fifty diameters on the four-inch,
we may try them with a high power on the three-inch. We shall only
succeed this time if our glass is of first-rate quality and the air is
perfectly steady.
The star lambda in Orion's head presents an easy conquest for the
three-inch, as it consists of a light-yellow star of magnitude three and
a half and a reddish companion of the sixth magnitude; distance 4", p.
43 deg.. There is also a twelfth-magnitude star at 27", p. 183 deg., and a tenth
or eleventh magnitude one at 149", p. 278 deg.. These are tests for the
five-inch, and we must not be disappointed if we do not succeed in
seeing the smaller one even with that aperture.
Other objects in Orion, to be found with the aid of our map, are: Sigma
627, a double star, magnitude six and a half and seven, distance 21", p.
260 deg.; Omicron Sigma 98, otherwise named iota Orionis, double, magnitude
six and seven, distance 1", p. 180 deg., requires five-inch glass; Sigma
652, double, magnitudes six and a half and eight, distance 1.7", p.
184 deg.; rho, double, magnitudes five and eight and a half, the latter
blue, distance 7", p. 62 deg., may be tried with a three-inch; tau, triple
star, magnitudes four, ten and a half, and eleven, distances 36", p.
249 deg., and 36", p. 60 deg.. Burnham discovered that the ten-and-a-half
magnitude star is again double, distance 4", p. 50 deg.. There is not much
satisfaction in attempting tau Orionis with telescopes of ordinary
apertures; Sigma 629 otherwise _m_ Orionis, double, magnitudes five and
a half (greenish) and seven, distance 31.7", p. 28 deg., a pretty object;
Sigma 728, otherwise A 32, double, magnitudes five and seven, distance,
0.5" or less, p. 206 deg., a rapid binary,[2] which is at present too close
for ordinary telescopes, although it was once within their reach; Sigma
729, double, magnitudes six and eight, distance 2", p. 26 deg., the smaller
star pale blue--try it with a four-inch, but five-inch is better; Sigma
816, double, magnitudes six and half and eight and a half, distance 4",
p. 289 deg.; psi 2, double, magnitudes five and a half and eleven, distance
3", or a little less, p. 322 deg.; 905, star cluster, contains about twenty
stars from the eighth to the eleventh magnitude; 1267, nebula, faint,
containing a triple star of the eighth magnitude, two of whose
components are 51" apart, while the third is only 1.7" from its
companion, p. 85 deg.; 1376, star cluster, small and crowded; 1361, star
cluster, triangular shape, containing thirty stars, seventh to tenth
magnitudes, one of which is a double, distance 2.4".
Public-domain text, read in full here on John Shaqi.
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