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
Camelopardalus is a very inconspicuous constellation, yet it furnishes
considerable occupation for the telescope. Sigma 390, of magnitude five,
has a companion of magnitude nine and a half, distance 15", 160 deg.. Sigma
385, also of the fifth magnitude, has a ninth-magnitude companion,
distance only 2.4", p. 160 deg.. According to some observers, the larger
star is yellow and the smaller white. The star 1 is a very pretty
double, magnitudes both six, distance 10.4". Its neighbor 2 of magnitude
six has an eighth-magnitude companion, distance 1.7", p. 278 deg.. The star
7 of magnitude five is also double, the companion of magnitude eight
being distant only 1.2". A glance at star cluster 940, which shows a
slight central condensation, completes our work in Camelopardalus, and
we turn to Ursa Major, represented in map No. 26. Here there are many
interesting doubles and triples. Beginning with iota we find at once
occupation for our largest glass. The magnitudes are three and ten,
distance 10", p. 357 deg.. In the double star 23 the magnitudes are four and
nine, distance 23", p. 272 deg.. A more pleasing object is sigma^2, a
greenish fifth-magnitude star which has an eighth-magnitude companion,
distance 2.6", p. 245 deg.. A good double for our four-inch glass is xi,
whose magnitudes are four and five, distance 1.87", p. 183 deg.. This is a
binary with a period of revolution of about sixty years, and is
interesting as the first binary star whose orbit was determined. Savary
calculated it in 1828. Near by is nu, a difficult double, magnitudes
four and ten and a half, distance 7", p. 147 deg.. In 57 we find again an
easy double magnitudes six and eight, distance 5.5", p. 4 deg.. Another
similar double is 65, magnitudes six and eight, distance 3.9", p. 38 deg.. A
third star, magnitude seven, is seen at a distance of 114" from the
primary.
We come now to Ursa Major's principal attraction zeta, frequently called
Mizar. The naked eye perceives near it a smaller star, named Alcor. With
the three-inch glass and a medium power we divide Mizar into two bright
stars brilliantly contrasted in color, the larger being white and the
smaller blue-green. Beside Alcor, several fainter stars are seen
scattered over the field of view, and, taken all in all, there are very
few equally beautiful sights in the starry heavens. The magnitudes of
the double are three and four, distance 14.5", p. 148 deg.. The large star
is again double, although no telescope has been able to show it so, its
duplicity being revealed, like that of beta Aurigae, by the periodical
splitting of the lines in its spectrum.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account