Half-hours with the Telescope eBook

Richard Anthony Proctor
This eBook from the Gutenberg Project consists of approximately 116 pages of information about Half-hours with the Telescope.

The star 11 Monocerotis is a fine triple star described by the elder Herschel as one of the finest sights in the heavens.  Our observer, however, will see it as a double (see Plate 3). [delta] Monocerotis is an easy double, yellow and lavender.

We may now leave the region covered by the map and take a survey of the heavens for some objects well seen at this season.

Towards the south-east, high up above the horizon, we see the twin-stars Castor and Pollux.  The upper is Castor, the finest double star visible in the northern heavens.  The components are nearly equal and rather more than 5” apart (see Plate 3).  Both are white according to the best observers, but the smaller is thought by some to be slightly greenish.

Pollux is a coarse but fine triple star (in large instruments multiple).  The components orange, grey, and lilac.

There are many other fine objects in Gemini, but we pass to Cancer.

The fine cluster Praesepe in Cancer may easily be found as it is distinctly visible to the naked eye in the position shown in Plate 1, Map I. In the telescope it is seen as shown in Plate 3.

The star [iota] Cancri is a wide double, the colours orange and blue.

Procyon, the first-magnitude star between Praesepe and Sirius, is finely coloured—­yellow with a distant orange companion, which appears to be variable.

Below the Twins, almost in a line with them, is the star [alpha] Hydrae, called Al Fard, or “the Solitary One.”  It is a 2nd magnitude variable.  I mention it, however, not on its own account, but as a guide to the fine double [epsilon] Hydrae.  This star is the middle one of a group of three, lying between Pollux and Al Fard rather nearer the latter.  The components of [epsilon] Hydrae are separated by about 3-1/2” (see Plate 3).  The primary is of the fourth, the companion of the eighth magnitude; the former is yellow, the latter a ruddy purple.  The period of [epsilon] Hydrae is about 450 years.

The constellation Leo Minor, now due east and about midway between the horizon and the zenith, is well worth sweeping over.  It contains several fine fields.

Let us next turn to the western heavens.  Here there are some noteworthy objects.

To begin with, there are the Pleiades, showing to the naked eye only six or seven stars.  In the telescope the Pleiades appear as shown in Plate 3.

The Hyades also show some fine fields with low powers.

Aldebaran, the principal star of the Hyades, as also of the constellation Taurus, is a noted red star.  It is chiefly remarkable for the close spectroscopic analysis to which it has been subjected by Messrs. Huggins and Miller.  Unlike Betelgeuse, the spectrum of Aldebaran exhibits the lines corresponding to hydrogen, and no less than eight metals—­sodium, magnesium, calcium, iron, bismuth, tellurium, antimony, and mercury, are proved to exist in the constitution of this brilliant red star.

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Half-hours with the Telescope from Project Gutenberg. Public domain.
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