Star Maps for Beginners: 50th Anniversary Edition - Softcover

I. M. LEVITT, PH.D., an internationally recognized scientist, is Director Emeritus of the Fels Planetariurn at The Franklin Institute in Philadelphia.

EXPLANATORY NOTES

The maps in this book are drawn exactly for a latitude of 40 degrees North -- the parallel for Philadelphia, Indianapolis, Denver, Reno, northern Japan, Korea, Peking (China), Ankara (Turkey), northern Greece, the "foot of the boot" of Italy and Madrid (Spain). However, they will serve amply well for places as far as six or seven degrees north or south of this specific latitude (or 400 to 500 miles), thus accommodating approximately 20 per cent of the world's population.

From a position north of the fortieth parallel an observer will be able to see some stars that are beyond the northern horizon indicated on our maps, and he will be unable to see some stars that are represented near the southern horizon on our maps. Conversely, from a position south of the fortieth parallel an observer will have a more extensive view to the south and a less extensive view to the north.

Another convention we have had to adopt is that of showing the sky for the times given for the exact Standard Time meridians. Determine what Standard Time is used in your area and the longitude corresponding to it. Eastern Standard Time is based on longitude 75 degrees West; Central Standard Time on longitude 90 degrees West; Mountain Standard Time on longitude 105 degrees West; Pacific Standard Time on longitude 120 degrees West. Then, determine your own longitude, from an atlas. Take the difference in degrees between your own longitude and that of your appropriate Standard Time meridian; multiply it by 4 to convert the degrees into minutes of time. If you are east of the Standard Time meridian, subtract the minutes from the time given on the map to determine the moment to see the sky as pictured; if you are west of the Standard Time meridian, add the minutes of longitude correction to the time given.

A glance at the maps will suffice to show how to use them. The words "Looking North," "Looking East," etc., serve to orient the maps to match the sky. If you look east, the words "Looking East" should be right side up, and so on.

The charts are arranged more or less in the form of what is called a Formée Cross, except that the sides of the panels are convex instead of concave. This largely eliminates distortion; the star groups have nearly the same shapes in the sky and on the maps. If a group straddles a division between two panels of the cross, reference to a preceding or following map will show the whole outline. Many star maps designed for the beginner permit so much distortion that they defeat their purpose; practically no one who is not already acquainted with the constellations can recognize them on those maps. Too many such star charts, showing all of the sky in circular form, with the pole or zenith in the center, or half the sky as half of a circular disk, with the zenith at the top, have been circulated with too little regard for the possibility of practical use by a beginner.

Undoubtedly, many deviations from exact representation of the heavens will be spotted in the maps in this book, but they are comparatively small; moreover, because of the "open" appearance of the charts, resulting from the elimination of vast numbers of faint stars, there is never much chance for confusion.

Many people do not know that red light promotes and maintains dark adaptation -- the ability of the eyes to see faint objects out-of-doors after leaving a brightly lighted house. In using the maps out of doors, a flashlight with two or three layers of red cellophane over the lens can be used, to make sure that the stars on the maps can be seen, while at the same time the stars in the sky will be plainly visible.

Some classicists may object to the mixture of Greek and Roman names in the myths. We know that the Romans borrowed the Greek myths, which in turn the Greeks had borrowed from the Phoenicians, who had borrowed them from the Babylonians, and so on. The names of the characters given here are, it is believed, the commonest ones associated with them. Many good books have been devoted to mythology per se; they can be found on most library shelves.

A very exhaustive book for those who wish to know the origins of the names of stars is Allen's Star Names and Their Meanings, which contains a wealth of information about the constellations; it has long been out of print, but it is available in many libraries. Much of the history is found in Basil Brown's Astronomical Atlases, Maps and Charts; this too is out of print, but can be found in some libraries.

Those who find their appetites whetted by this elementary book of maps may care to go on to a more advanced atlas, in which many more stars, as well as the Bayer and Flamsteed designations, are given. Those by Schurig-Götze and by Norton are good ones. The most modern is Antonin Becvar's de luxe Atlas of the Heavens, which can be purchased in a less expensive edition called Field Atlas of the Heavens. Prices of many such publications can be obtained from the Sky Publishing Corporation, Harvard Observatory, Cambridge 38, Mass., which also publishes a fine monthly astronomical magazine, Sky and Telescope.

Many amateurs (beginners, really) have asked the authors to recommend material that would be helpful in pursuing the subject. The first thought would be to consult school and public libraries; even if the selection is small and poorly chosen, the beginner can profit by reading through it. Then, with references to newer publications in such journals as Sky and Telescope, the better volumes being printed today can be obtained or, perhaps, recommended to the libraries. The volume of material in this Space Age is enormous.

THE HISTORY AND DEVELOPMENT OF THE CONSTELLATIONS

Modern astronomy has become a highly specialized study, with a good knowledge of at least elementary physics and mathematics required to follow its many ramifications. We could hardly expect it to be otherwise, in a science which attempts to embrace as its field the whole of creation -- the universe.

The findings of modern astronomy make fascinating reading for one who is willing to realize that no one can expect to grasp quite all of what is contained even in a so-called "popular" book, without at least some measure of concentration and connected thought. This is not peculiar to astronomy, of course; modern physics, chemistry, geology, botany -- even economics and political science -- are such specialized subjects that the general reader must appreciate his handicaps and must not expect to be able to grasp completely in one hurried reading what other men learn only after many years of concentrated study.

But there is one part of astronomy in which the professional astronomer has little interest, and it is in this field that the interested amateur can become as proficient as the greatest of the ancient astronomers. This is the study of the apparent face of the sky, to the end of being able to identify the star groups or constellations, and to name many of the stars. One need not be a geologist to enjoy rolling hills or soaring mountains, or a botanist to enjoy a flower; to know and enjoy the stars requires no technical knowledge, but it is an achievement of which one may well be proud. It leads to greater appreciation of great works of music, art, and literature, for the heroes who fill the sky are favorites in these other aesthetic endeavors of mankind. Today most of us read very little of the old legends of Rome and Greece, but a study of the constellations will prove an incentive to greater enjoyment of these old stories.

The sky is parceled into named areas called constellations, as our country is divided into named areas called states. It is in just this way that a modern astronomer regards the constellations -- as named areas -- and it is quite likely that those forgotten stargazers who originally named the constellations thought of them in the same way. Sometime in between, however, there arose a demand that a constellation named Hercules, for example, should look like Hercules, the prodigiously strong son of Jupiter. Suppose we were to insist that a state named Washington should look like our first president! Or suppose the states of Georgia, North and South Carolina, Maryland and Virginia should have their boundaries changed, to force those states to be profile portraits of a King George, a King Charles, a Queen Mary, and a Queen Elizabeth (the Virgin) of England! We should regard such a thing as at least slightly silly, yet almost everyone is under the impression that the constellations are supposed to be pictures, because they bear the names of persons, creatures, and objects.

The earliest remaining complete description of the sky as seen from Greece was written by the poet Aratus, whom we shall mention again. He stated that certain mortals, "in ages long agone," finding that it was a tedious task and not particularly helpful in identification to give a name to every star, decided to name them in groups. Then, as we might refer to "that biggest oak tree in Johnson's meadow," the early watchers of the sky might speak of "the brightest star in the constellation Auriga." How soon after the naming process the pictures were associated with the constellations we do not know, but it must have been very early.

The earliest complete representation of the heavens as they were considered at the time appears to be the famous Farnese Globe, now in the Naples Museum. Discovered in Italy, it consists of white marble, and portrays Atlas on one knee, supporting on his bowed head and shoulders the celestial sphere, which he steadies with his hands. In an excellent state of preservation, it dates from at least as early as the first century before the Christian Era. Beautifully sculptured in raised relief, in the correct positions on the sphere, are the pictures of the constellations, but images of the stars are not shown.

Similarly, the earliest manuscript map of the sky contains only the constellation figures, and not the stars. The so-called Planisphere of Geruvigus, included in a Roman manuscript version of Aratus, dates from the second century A.D. and is now in the British Museum. It differs from the Farnese Globe and resembles modern maps in that it represents the actual face of the sky; that is, it shows the constellations as seen from the inside of the celestial sphere, as we see them from the earth.

In the earliest map showing the constellation figures and also the stars tolerably well located, we find a return to the practice of showing the sky as it appears on the surface of the sphere, as seen from the outside. It is the work of Peter Bienewitz (Latinized as Petrus Apianus), published as a single sheet, at Ingolstadt on August 5, 1536. It is a woodcut, well executed, representing forty-eight constellations.

But it was Johann Bayer, a lawyer and amateur astronomer of Augsburg, who published (1603) the star atlas which was the prototype of a number of fine atlases prepared by later astronomers. Bayer's Uranometria shows the positions of about 1250 stars, with their relative brightnesses quite accurately represented, and upon the star groups are shown the constellation pictures. The fifty-one plates were exquisitely engraved on copper by Alexander Mair. Here we find again a star map showing the sky as seen from the inside, as we actually see it, and practically every map of the sky (except, of course, celestial globes) has, since that time, been drawn this way. To Bayer, too, we owe our modern method of designating most of the naked-eye stars by letters of the Greek alphabet, in each constellation. His atlas passed through several editions.

It was more than a century before the star maps of Bayer were equaled, when John Flamsteed, the British Astronomer Royal, observed the positions of the stars for a catalogue and atlas (posthumously published in 1729). The constellation figures are in some respects superior to those of Bayer, without, perhaps, the same beautiful workmanship. There were many editions of this atlas, in which the practice of numbering the stars in each constellation, in order from west to east, was established. At a later moment, we shall explain and illustrate these designation schemes of Bayer and Flamsteed.

Later star atlases were published by Doppelmayer (1742), Bevis (1750), Burritt (1851) and others, but perhaps only that of Johann Elert Bode, about 1800, need be mentioned here. Bode seems to have been the first one to draw star charts to show the skies month by month, a scheme which has been quite popular for several generations, particularly for star maps intended for the beginner. It is a similar scheme which has been followed for the charts in this book.

Besides the sculptures and maps showing the pictures over the whole sky, there have come down to us descriptions of the sky and fragmentary representations which push yet farther back our knowledge of the framers of the constellations. Originally, modern astronomers believed that the Greeks had apportioned the sky into star groups, because most of the legends connected with the figures in the sky were known to be Greek. But, with the growth of our knowledge of the civilizations of the valley of the Tigris and Euphrates rivers, there has come a realization that many of the Greek myths had a Semitic origin. The Greeks simply changed the settings and the names, and took over the plots of the legends. Might they not similarly have taken over the constellations of the Euphratean peoples?

We know that the Akkadians and Sumerians, non-Semitic forerunners of the Babylonians, had names for many of the stars, chosen particularly from the words in use in shepherding. The stars were known as the "heavenly flock"; the bright star Arcturus was called Sibzianna, the "star of the shepherds of the heavenly herds." The sun was called the "old sheep"; the planets were the "old-sheep stars." This was the kind of astronomy inherited by the Babylonians from their predecessors in the Euphratean valley.

Examination of baked-clay tablets and cylinder seals which date from 3500 to 500 B.C. gives a few clues. One of the older myths describes a battle between Marduk, city-god of Babylon, and the dragon Tiamat. On a clay cylinder seal dating from at least as early as 3000 B.C., Izhdubar (better known in English literature as Gilgamesh) is pictured kneeling on a dragon. The Greeks inherited a constellation called En Gonasin, the Kneeler, who has one foot on the head of a dragon. They were reminded of their hero Herakles (Roman Hercules) and his struggle with the Dragon which guarded the Golden Apples of the Hesperides. So Hercules and Draco are surely two very old constellations. Another is Leo, the Lion, which is shown on an ancient clay tablet, with the star Regulus marking his heart. A cuneiform synthesis of all earlier inscriptions (known as the "Creation Legend," compiled about 650 B.C., during the reign of Assurbani-pal) indicates that there were recognized thirty-six constellations, divided into three groups -- northern, zodiacal, and southern.

The poems of Homer (Iliad and Odyssey, dating perhaps from the middle of the ninth century B.C., according to Herodotus) contain references to the constellations, but inasmuch as Homer was probably only the collector of the tales and ballads of earlier times, these constellations must be much older. The writings of Hesiod (Theogonia and Works and Days), about a century later, mention Arcturus, the Pleiades, the Hyades, Sirius and Orion, while Homer had referred to Ursa Major, in addition to these.

It is more than likely that the early Greeks received their astronomical lore from the Euphrateans, by way of the Phoenicians, a ...