William Tyler Olcott

“ Although Jupiter appears to move slowly, it really travels at the incomprehensible rate of five hundred miles a minute.
The most interesting feature about Jupiter for the amateur astronomer consists in observing four of its moons, which are visible with a small telescope. They appear like mere dots of light, and their transit of or occultation with the planet (that is, their disappearance before or behind its disk) can be watched, and is a never failing source of pleasure. A large telescope alone reveals Jupiter's four other moons. ”

“ There is nothing of particular interest to be noted in this asterism. It does not appear on modern star charts and is considered obsolete.
So great is the distance that separates us from the stars that as for the great majority had they been blotted out of existence before the Christian era, we of to-day should still receive their light and seem to see them just as we do. When we scan the nocturnal skies we study ancient history. We do not see the stars as they are but as they were centuries on centuries ago. ”

“ The ruddy star Antares, the brightest star in the constellation, is in the heart of the Scorpion. It lies about 40° southwest of Ras Alhague, in Ophiuchus, and a little over 20° west of the bow of Sagittarius. The fact that it is the most brilliant star in this region of the sky renders its identity unmistakable. It is one of the reddest stars in the firmament. ”

“ Running east from α, at almost equal distances, are four other stars, two of which are of the second magnitude. The most easterly one is β Persei, known as Algol, the famous variable. Lines connecting the stars γ Andromedæ, Algol, and α Persei form a right-angled triangle. The right angle is marked by Algol.
The chief object of interest in this constellation is the great nebula, the first to be discovered. It can be seen by the naked eye and it is a fine sight in an opera-glass. ”

“ The planet may be mistaken for the first magnitude stars, Antares in Scorpius, and Aldebaran in Taurus, near which it frequently passes.
The fixed stars, however, twinkle, while Mars glows steadily. If there is any doubt in the student's mind as to the identity of the planet, a few nights of observation, noting the changes in the planet's position, will decide the point. It takes Mars about fifty-seven days to pass through one constellation in the Zodiac. ”

“ The nearest bright star west of Polaris is γ Cephei. Cepheus is an inconspicuous constellation, lying partly in the Milky Way. A view of this constellation through an opera-glass will repay the observer. Cepheus is characterized by a rude square, one side of which is the base of an isosceles triangle. Look for the so-called garnet star μ, probably the reddest star visible to the naked eye in the United States. The star ζ has a blue companion star. ”

“ Betelgeuze, in Orion, Procyon, in Canis Minor, and Sirius form a nearly equilateral triangle. These stars with Naos, in the Ship, and Phaet, in the Dove, form a huge figure known as the Egyptian "X."
From earliest times Sirius has been known as the Dog of Orion. It is 324 times brighter than the average sixth-magnitude star, and is the nearest to the earth of all the stars in this latitude, its distance being 8.7 light years. At this distance the Sun would appear as a star a little brighter than the Pole Star. ”

“ By careful observation for over fifty years the meteors, generally speaking, have been so arranged that they come under the head of one of the nearly three hundred distinct showers which are now recognized by astronomers.
Many of these showers are too feeble and faint to be worthy of the attention of one not especially interested in the subject, but certain ones are well worth observing. [Pg 131] There is always a pleasure in being able to recognize at a glance a certain definite manifestation of nature, be it a rare flower or a flashing meteor. ”

“ Arcturus, Cor Caroli, Denebola, and Spica form a figure about 50° in length, called the Diamond of Virgo.
The equator, ecliptic, and equinoctial colure intersect each other at a point close to the star η. This is called the autumnal equinox.
The star ε is known as the "Grape Gatherer." It is observed to rise just before the sun at vintage time.
Within the rude square formed by Denebola, and ε, γ, and β, Virginis, the telescope reveals many wonderful nebulæ; hence this region of the sky has been called "The Field of the Nebula."
Spica is an extremely beautiful pure white star. ”

“ The North Star is always elevated as many degrees above the horizon as the observer is north of the equator.
Compare the light of the four stars forming the bowl of the "Little Dipper," as they are each of a different magnitude. A standard first-magnitude star is 21⁄2 times brighter than a standard second magnitude star, etc. ”

“ The Milky Way in the vicinity of Cassiopeia is particularly rich, and well repays a search with an opera-glass.
"The Galaxy covers more than one tenth of the visible heavens, contains nine-tenths of the visible stars, and seems a vast zone-shaped nebula, nearly a great circle of the sphere, the poles being at Coma and Cetus." ”

“ The greatest distance it ever departs from the sun on either side varies approximately from sixteen to twenty-eight degrees. Its motion resembles a pendulum, swinging from one side of the sun to the other. ”

“ It may be that they have observed the heavens from time to time in a desultory way and have no notion that valuable and practical scientific research work can be accomplished with a small glass. If those who are willing to aid in the great work of astrophysical research will communicate with the author he will be pleased to outline for them a most practical and fascinating line of observational work that will enable them to share in the advance of our knowledge respecting the stars. It is work that involves no mathematics, and its details are easily mastered. ”

“ A triangle is formed by Vega, Altair, and Ras Alhague, in the Serpent Bearer, which is about 30° west of Altair.
This is a double constellation composed of Aquila and Antinoüs. Altair is in the neck of the Eagle, Alschain in the head of Antinoüs.
When the moon is absent, a rude arrowhead can be traced out, embracing almost all the stars in Aquila.
η is an interesting variable star, changing from magnitude 3.5 to 4.7 and back again within a period of 7 days 4 hours 12 minutes. ”

“ The splendid first-magnitude star Rigel is diagonally opposite Betelgeuze, and the girdle and sword of the Hunter lie within the parallelogram, a very striking group. The former is represented by three bright stars in a line 3° long known as the "Three Stars," because there are no other stars in the heavens that exactly resemble them in position and brightness. ”

“ Venus.
Venus approaches nearer to the earth and is more brilliant than any other planet. It is bright enough to cast a shadow at night, and is sometimes visible even at noonday. It is almost as large as the earth, and appears to oscillate, as Mercury does, on either side of the sun. ”

“ Castor and Pollux, in Gemini, point southeast to it.
The constellations Crater, the Cup, and Corvus, the Crow, both stand on the coils of Hydra, south of Denebola, the bright star in the tail of the Lion.
Hydra is supposed to be the snake shown on a uranographic stone from the Euphrates, 1200 b.c.
The little asterism Sextans, the Sextant, lies in the region between Regulus and Alphard. It contains no stars brighter than the fourth magnitude. ”

“ As this work is designed primarily to cover what is observable in the starlit heavens with the naked eye, the subject of meteors, or shooting-stars, comes properly within its scope.
There are few persons, if any, who have not witnessed the sight of a splendid meteor speeding across the sky, and such a sight always calls forth exclamations of wonder and delight. ”

“ It is claimed that Cepheus was known to the Chaldæans twenty-three centuries before our era.
Surrounding δ, ε, ζ, and λ, which mark the king's head, is a vacant space in the Milky Way, similar to the Coal Sack of Cygnus.
About 4° from γ, in the direction of κ is a pretty pair of sixth-magnitude stars.
Owing to precession, γ, β, and α Cephei will be successively the Pole Star in 4500, 6000, and 7500 a.d. respectively. ”

“ Arrhenius, a Nobel Prize winner, having had occasion repeatedly to treat new questions of a cosmological nature, questions largely arisen from new discoveries and observations within the scope of astronomy, opens to the reader vast new vistas, through the study of the relation of the stars to the "Milky Way" and through observations of our neighbor planets. ”

“ Confusion, therefore, respecting their identity can only arise in connection with a study of one of the twelve constellations named above, so that whenever a star of any size is seen in one of these constellations, not accounted for in the diagram, the student may conclude that this is a planet; especially if the unknown star does not twinkle. ”

“ The cluster 13 M., the Halley Nebula, can be easily seen in an opera-glass. In a recent photograph of this cluster 50,000 stars are shown in an area of sky which would be entirely covered by the full moon.
Hercules occupies the part of the heavens toward which the sun is bearing the earth and planets at the rate of twelve miles a second or 373 million miles a year. ”

“ In addition to first-magnitude stars the rhyme refers to the head of Capricornus, the Sea Goat, the Great Square of Pegasus, and Orion's Belt. All except Arcturus rise between 9 and 9.30 p.m. Arcturus rises at 10 p.m., February 1st.
Eight months of the year are identified by the position of the Dipper at 9 p.m. In April and May it is north of the zenith. During July and August it is west of north. In October and November it lies close to the northern horizon and in January and February it is east of north with the pointers highest. ”

“ The apparent velocity of the meteors is between ten and forty-five miles a second, and their average height is about seventy-six miles at first appearance, and fifty-one miles at disappearance. Occasionally a meteor is so large and compact as to escape total destruction, and falls to the earth. ”

“ The northern row if extended would reach Taurus, the southern one Orion. Note the fine cluster 35 M. Herschel discovered Uranus in 1781 a short distance southwest of it. Two wonderful streams of little stars run parallel northwest on each side of the cluster. Where the ecliptic crosses the solstitial colure is the spot where the sun appears to be when it is farthest north of the equator, June 21st. Castor is a fine double for a telescope, and Pollux has three little attendant stars. An isoceles triangle is formed by Castor, Aldebaran in Taurus, and Capella in Auriga. ”

“ A line drawn from Nath in Auriga to Pollux in Gemini, and prolonged about 15°, ends in Præsepe, the Manger, the great star cluster in Cancer, which is also called "The Bee Hive." It contains 300 stars. The stars γ and δ are called the Aselli—the ass's colts feeding from the silver manger. ”

“ As to the number of the stars as classified according to their magnitude, that is their brightness, it may be mentioned that there are approximately 20 stars of the first magnitude, 65 of the second, 300 of the third, and 450 of the fourth. We cannot see stars fainter than the sixth magnitude with the naked eye. ”

“ A Field Book of the Stars
16mo. With Fifty Diagrams.
To facilitate the fascinating recreation of star-gazing the author has designed this field-book. All matters of a technical or theoretical nature have been omitted. Only what the reader can observe with the naked eye or with an opera-glass have been included in it. Simplicity and brevity have been aimed at, the main idea being that whatever is bulky or verbose is a hindrance rather than a help when one is engaged in the observation of the heavens. ”

“ No two of the seven stars composing the Crown are moving in the same direction or at the same rate.
α Coronæ is seventy-eight light years distant and sixty times brighter than the sun. [Pg 51]
CORONA BOREALIS
[Pg 52]
HERCULES (her ́-kū-lēz) —THE KNEELER.
Location.—A line drawn from either Vega, in Lyra, or Altair, in Aquila, to Gemma, in Corona Borealis, passes through this constellation. The left foot of Hercules rests on the head of Draco, on the north, and his head nearly touches the head of Ophiuchus on the south. ”

“ This pathway is divided into twelve equal parts of thirty degrees each, and to these twelve divisions are given the names of the constellations of the Zodiac in the following order: Aries (♈) , Taurus (♉) , Gemini (♊) , Cancer (♋) , Leo (♌) , Virgo (♍) , Libra (♎) , Scorpio (♏) , Sagittarius (♐) , Capricornus (♑) , Aquarius (♒) , Pisces (♓) .
The sun, starting from the first degree of Aries, the [Pg 116] first day of spring, passes through one constellation a month. The planets follow the same pathway. ”