How to Identify the Stars

7/30/2019 How to Identify the Stars

1/92


2/92

CORNELLUNIVERSITYLIBRARY

BOUGHT WITH THE INCOMEOF THE SAGE ENDOWMENTFUND GIVEN IN 1891 BYHENRY WILLIAMS SAGE


3/92

How to identify the stars,

3 1924 012 311 472


4/92

Cornell UniversityLibrary

The original of tiiis book is intine Cornell University Library.

There are no known copyright restrictions inthe United States on the use of the text.

http://www.archive.org/details/cu31924012311472


5/92


6/92


7/92

HOW TO IDENTIFY THE STARS


8/92

The.

THE MACMILLAN COMPANYNEW YORK BOSTON - CHICAGOATLANTA SAN FRANCISCOMACMILLAN & CO., LimitedLONDON BOMBAY CALCUTTAMELBOURNE

THE MACMILLAN CO. OF CANADA, Ltd.TORONTO


9/92

HOW TO IDENTIFYTHE STARSBY

WILLIS I. MILHAM, Ph.D.FIELD MEMOKIAL PROFESSOR OF ASTRONOMY

IN WILLIAMS COLLEGE

THE MACMILLAN COMPANY1909

rAll fHgkts reserved


10/92

COPYKIGHT, 1909, By the MACMILLAN COMPANY.

Set up and electrotyped. Published June, 1909.^

Norlnoal) ^nssJ. S. Cuihing Co. Berwick Jt Smith Co.

Norwood. Mu>., U.S.A.


11/92

CONTENTSFAGE

I. Introduction iII. The History and Number of the Constella-

tions 3III. The Methods of Designating a Star . . 12IV. Star Magnitudes 15V. Star Colors 20VI. The Number of the Stars .... 21VII. The Method of Locating the Stars and

Constellations 23VIII. The Method of Further Study . 33


12/92


13/92

I. INTRODUCTIONThe ability to recognize the more brilliant

stars and to locate the more conspicuous con-stellations or star groups, is both an interest-ing and a useful acquirement. The number ofpeople who have a real interest in popular as-tronomy and a fair acquaintance with the starsand constellations is steadily increasing andthey find real pleasure in their information. Tothe meteorologist who would make observa-tions of the position of the streamers of the Au-rora Borealis or locate the place of the appear-ance and disappearance of bright meteors, aknowledge of the stars and constellations isabsolutely necessary. The best way to locatethe position of an auroral streamer without theuse of apparatus is to observe the stars betweenwhich and over which it extends. Similarly thepoint of appearance and disappearance of a me-teor has been definitely determined if the near-est star in each case has been noted. If great


14/92

2 HOW TO IDENTIFY THE STARSexactness is desired, the angular distance anddirection of the point in question from thenearest star may be estimated. Whenever anobject is thus located by means of the stars, theexact time of observation and the place of ob-servation (latitude, longitude, and elevation)must also be stated. From such observationsmade at two, preferably more, stations, thedistance, height, and direction of an auroraldisplay, and the distance, height, direction ofmotion, velocity of motion, and orbit in spaceof a meteor may be determined by computa-tion.The purpose of the constellation tracings and

the descriptive material here given, is to serveas a guide in taking the first steps in learningthe stars and constellations and also to pointthe way to the acquisition of further informa-tion on the part of those who desire it. Themethod here followed and the material presentedis essentially the same as that used in the courseon Descriptive Astronomy in Williams College.


15/92

II. THE HISTORY AND NUMBER OFTHE CONSTELLATIONSThe first definite information concerning the

constellations comes from Claudius Ptolemy atthe Alexandrian School of Philosophy in about150 A.D. He was a great systematizer of in-formation and summarized the astronomicallearning of his time. His original writings inthe Greek are lost, but an Arabic translation ofhis manuscript on Astronomy, called the "Al-magest," has come down to us. In it he enu-merates, describes, and locates 48 constellations21 northern, 15 southern, and 12 zodiacal.These constellations by no means covered thewhole sky, as a large part of the southern hemi-sphere was not mapped and there were oftenunmapped spaces between the constellations.As the centuries passed, the need of more con-stellations became apparent, but it was consid-ered sacrilegious to add to the Ptolemaic list.Finally, in 1601, two constellations were added

3


16/92

4 HOW TO IDENTIFY THE STARSby Tycho Brahe. This opened the way, and fortwo centuries nearly every astronomer of noteconsidered it his duty to map a group of starsand give to the group a name of bis own choos-ing. Thus by 1800 there were at least 109fairly well known constellations, and a large con-stellation (Argo) in the southern hemispherewas divided into four, thus making 112. Thedifficulties w^ere now as great as before newconstellations had been added, for some of theconstellations overlapped and names had beengiven to some of th&m which could never be-come international. Graduall)^ by practicallycommon consent, 24 were dropped, so that atpresent there are 88 constellations. The ac-companying list shows the number of constel-lations added by each astronomer.


17/92

mSTORY OF THE CONSTELLATIONS140 A.D.


18/92

6 HOW TO IDENTIFY THE ST.\RSnorthern constellations. Some of the southernconstellations have boundaries which are forconsiderable distances arcs of great or smallcircles. The constellations are also of veryunequal size, some being ten times as largeas others.

The following list contains the names ofthe constellations, the Latin genitive of thename, the meaning of the name, and thename of the originator of the constellation :

Name


19/92

HISTORY OF THE CONSTELLATIONSName


20/92

HOW TO IDENTIFY THE STARSName

Erid'-anusFor'-naxGem'-iniGrusHer'-culesHorolo'-giumHy'-draHy'-drusIn'-dusLacer'-taLe'-oLe'-o Mi'-nor

Le'-pusLi'-braLu'-pusLynxLy'-raMa'-lusMen'-saMicrosco'-pium

Monoc'-eros

Mus'-caNor'-maOc'-tansOphiu'-chus

GenitiveErid'-aniForna'-cisGemino'-rumGru'-isHer'-culisHorolo'-giiHy'-draeHy'-driIn'-diLacer'-tseLeo'-nisLeo'-nis

Mino'-risLep'-orisLi'-braeLu'-piLyn'-cisLy'-rseMa'-liMen'-sseMicrosco'-pii

MeaningThe riverFurnaceTwinsCrEineHerculesClockSnakeWater snakeIndianLizardLionLesser lion

HareBalanceWolfLynxHarpMastTableMicroscope

Monocero'-tis Unicorn

Ori'-on

Mus'-cseNor'-maeOctan'-tisOphiu'-chi

Orio'-nis

FlyRuleOctantSerpent

carrierOrion

PkoposerPtolemyLa CaillePtolemyBayerPtolemyLa -CaillePtolemyBayerBayerHeveliusPtolemyHevelius

PtolemyPtolemyPtolemyHeveliusPtolemyLa CailleLa CailleLa Caille

Hevelius orBartschius

BayerLa CailleLa CaillePtolemy

Ptolemy


21/92

HISTORY OF THE CONSTELLATIONSName


22/92

10 HOW TO IDENTIFY THE STARSIt will be seen that there are three kinds of

names used ; names of animals, names bor-rowed from mythology, and names of piecesof apparatus.When and where the constellations were

originally designed are questions which havereceived a great deal of attention and study.This subject can be merely sketched in out-line here. The list of 48 constellations givenby Ptolemy was by no means original withhim, but was simply a slight revision of anearlier list by Hipparchus, date about 140 b.c.And even before his time a fairly full descrip-tion of the constellations can be found in thepoem of Aratus of Soli, date about 280 b.c.But this was simply a versification of anearlier astronomical work by Eudoxus in 370B.C., and this in turn, as we now know, wasnot based on observations made by the Greeks,but on astronomical information that was atthat time at least two thousand years old.There are three sources of information as tothe origin of the constellations: first, the in-ternal evidence from the constellations them-selves ; secondly, the documentary evidence in


23/92

HISTORY OF THE CONSTELLATIONS iithe form of references in the early writings;thirdly, the inscriptions on monuments, tablets,coins, etc., which are continually being dis-covered. The originators of the constellationsnaturally portrayed the things with which theywere familiar. The elephant, camel, tiger, andcrocodile are not represented. This wouldexclude India and Egypt as possible placesof origin. The portion of the sky left un-mapped shows the portion of the sky notvisible to them. They must thus have livedin about 38 north latitude. In short, all linesof evidence show that the constellations prob-ably originated in the Euphrates valley, andwere practically complete as early as 3000 B.C.What we have is thus the Latin form of aGreek digest of very early information. Forfurther information about the origin of theconstellations, seeBROWN, Primitive Constellations ; Williams and Nor-

gate, London, 1899.LOCKYER, The Dawn of Astronomy ; The Macmillan

Company, 1894.MAUNDER, Astronomy without a Telescope, Chapter I

"Knowledge" Office, London, 1902. .MAUNDER, The Oldest Picture-book of All; The Nine-teenth Century Magazine, September, 1900.


24/92

III. THE METHODS OF DESIGNATINGA STARThe oldest, but now obsolete, method of

designating a particular star was to describeits position in the constellation. The portionof the sky belonging to a certain constellationwas supposed to be covered by a representa-tion or picture of the thing after which theconstellation was named. Thus a star mightbe described as located "in the head of Her-cules" or "in the right knee of Bootes" or"in the horn of the bull." Many star chartsstill give those old pictures in connectionwith the constellations.

There are four modern methods of designat-ing a star, (i) By name. Hundreds of starshave received individual names, but less thana hundred of these are now in general use.They are usually of Latin, Greek, or Arabicorigin, and are either proper names or de-scribe position. For example: Regulus, Spica,


25/92

THE METHODS OF DESIGNATING A STAR 13Aldebaran. (2) By means of a letter. In 1603Bayer introduced the system of designatingthe stars in a constellation by means of theletters in the Greek alphabet. These are, inorder :

a alpha


26/92

14 HOW TO IDENTIFY THE STARSfainter stars which had not been lettered, andthey were numbered in order of position fromwest to east. For example: 6i Cygni, 50Cassiopeiae. (4) By catalogue number. Inthe case of some faint stars visible to thenaked eye, and nearly all stars visible in atelescope only, the star is designated as havinga certain number in a certain catalogue. Itis usually the first catalogue in which it oc-curred or some very well known comprehen-sive catalogue. For example: Groombridge966, B.A.C. 4536.The last three of the four modern methods

seldom overlap at present. The brighter starsare usually lettered. Those which are fainter,but still visible to the naked eye, are usuallynumbered, while telescopic stars are referredto simply by catalogue and number. If a starhas a proper name, this is usually given inaddition to the Bayer letter.


27/92

IV. STAR MAGNITUDESThe term " magnitude " when applied to a

star refers simply to its brightness and notto its volume or mass. Ptolemy arbitrarilygraded the stars visible to the naked eye intosix classes or magnitudes, the sixth being thefaintest and the first the brightest. Thereason for having six magnitudes rather thanmore is not known, unless it is because theeye without the help of instruments is unableto make finer distinctions. After the tele-scope was invented, the number of magni-tudes had to be increased so as to includethese faint telescopic stars, but there was nouniformity among different observers in ex-tending the system. As the result, the mag-nitude of a faint star, as determined by differ-ent observers, might differ by even two orthree. As measurements became more exact,it also became desirable to subdivide magni-tudes,

'S


28/92

i6 HOW TO IDENTIFY THE STARSIt had been noticed for some time that,

roughly speaking, a star of the first magnitudewas about one hundred times as bright as astar of the sixth. In 1850, Pogson proposedto make the Vioo, or 2.512, the uniform ratiobetween successive magnitudes.

Thus, /5i = Vioo b^, where b^ is the bright-ness of a first magnitude star and (J^ that of asecond.

Similarly,


29/92

STAR MAGNITUDES 17the difference in magnitude. By means of thisformula, if the magnitudes of two stars are given,the ratio of brightness may be computed, and ifthe ratio of brightness and the magnitude ofone star is given, the magnitude of the othermay be computed.Example i. If the magnitude of Mizar

{C Ursce Majoris) is 2.4 and the magnitude ofAlkor (g UrsEe Majoris) is 4.0, find their ratioof brightness.

logio ratio = 0.4(4.0 2.4)= 0.4(1 .6) = 0.64.Ratio of brightness = 4.37.Example 2. If a star is 30 times as bright as

Polaris (a Ursae Minoris), magnitude 2.1, find itsmagnitude. Iogio30= 0.4(2.1-;!;),

1.477 = 0.84 0.4 ;r,0.4^1;= -0.637,

x-= -1.59-The magnitude is - 1.59, and this is the mag-nitude of Sirius (a Canis Majoris).

This definite system of star magnitudes wasgradually adopted, and now all star magnitudesare expressed in it. Some star must be con-


30/92

i8 HOW TO IDENTIFY THE STARSsidered to be fundamental, that is, to have adefinite unchanging magnitude, and the mag-nitudes of the other stars must be determinedin terms of its magnitude. Polaris (a UrsaeMinoris) is usually taken as the fundamentalstar. By means of photometers all otherstars are compared with it, either directly orindirectly, and the ratio of brightness, andthus the magnitude, determined. The workof the Harvard College Observatory in thisconnection has been particularly noteworthy.Here the actual standard is not Polaris but themean magnitude of one hundred circumpolarstars of about the fifth magnitude.

In this system of magnitudes, the nakedeye can perceive stars of about the sixth mag-nitude if the air is clear and free from haze.One disadvantage of the system is the factthat there are stars brighter than the firstmagnitude. A star 2.51 times as bright asone of the first magnitude would be of theo magnitude. A star 2.51 times as bright asthat would be of the -i magnitude. Thusfor a very bright object a negative magnitudemust be used. There is one star which has


31/92

STAR MAGNITUDES 19a negative magnitude, Sirius (a Canis Majoris) 1.6. On the same scale the sun would havea magnitude of 26.3.The magnitudes of stars remain remarkably

constant. There are only about 500 stars inconnection with which a variation in magni-tude has been detected, and only about 50 ofthese are visible to the naked eye. Thechange in magnitude may be a steady changein one direction, an irregular fluctuation, or aperiodic variation. If the fluctuation is irreg-ular, only the limits can be stated. If thevariation is periodic, such facts as the limitsof the variation and the period may be deter-mined.


32/92

V. STAR COLORSMost of the stars appear to us as white,

although in a few cases the star appears tobe tinged with color. The following list prob-ably includes the various colors as they appearto the naked eye: greenish white, bluish white,white, yellowish white, orange-white, reddishwhite. Stars are sometimes said to be yellow,orange, or red, but in every case the white pre-dominates to such an extent that it is reallyonly a tinge of the color in question that isperceived.As seen through the telescope all the spec-

trum colors may be noticed, but in every casethey are strongly mixed with white.The causes of these differences in color are

differences in temperature and chemical com-position.


33/92

VI. THE NUMBER OF THE STARSThe opinion is often expressed that the starsappear almost countless in number. As a mat-

ter of fact the total number visible to the nakedeye is only about 6,000. Only one-half of theseare visible at any one time, and a small amountof haze greatly reduces the number that isvisible, particularly near the horizon. Thuson a night which would be considered clearonly about 2,000 stars are visible. As wassaid before, the sixth magnitude is usuallyconsidered the limit of visibility to the nakedeye. The following table gives the numberof stars between each magnitude. The sec-ond line of the table gives the values of 4 x 3'",where m is the magnitude. The agreement isremarkably close. Expressed in words, the lawwould be that there are about three times asmany stars in each magnitude as in the pre-ceding magnitude.

21


34/92

22 HOW TO IDENTIFY THE STARSMagnitude o


35/92

VII. THE METHOD OF LOCATING THESTARS AND CONSTELLATIONS

The method of locating the stars and con-stellations here advocated is by means of theso-called constellation tracings. Most of theconspicuous constellations contain bright starswhich, when connected by lines, form figures,such as a triangle, square, W, sickle, etc.,which are easily remembered and quickly rec-ognized. After these tracings have once beenlearned and noticed, as soon as the eye fallsupon that part of the sky, it instinctively runsthrough the tracing, and the constellation isthus recognized and its stars identified. Forconvenience in locating them, the 88 constel-lations have been divided into four groups.The first group consists of 28 conspicuousconstellations with tracings. The second groupcontains the five constellations which are chieflyconspicuous on account of a single very brightstar. The third group of 19 comprises the

23


36/92

24 HOW TO IDENTIFY THE STARSinconspicuous constellations, while the fourthgroup contains the 36 constellations whichare too far south to be seen at all or well seenfrom the United States. The following tablein four parts gives these four groups of con-stellations:

THE- 88 CONSTELLATIONS DIVIDED INTO FOURGROUPSI. The 28 Conspicuous Constellations with TracingsAndromeda


37/92

LOCATING THE STARS AND CONSTELLATIONS 25III. The 19 Inconspicuous Constellations

AquariusCamelopardalisCancerCapricornusCepheusCetusComa BerenicesCraterEquuleus

EridanusHydraLacertaLeo MinorLynxMonocerosPiscesScutumSextans

Vulpecula

IV. The 36 Southern .ConstellationsAntlia


38/92

26 HOW TO IDENTIFY THE STARSCharts I. to IV. show the position of the

constellations at 9 p.m. during January, April,July, and October, During a following monththey would show the position two hours earlier,and during a preceding month two hours later.That is, stars come into the same position twohours earlier after the lapse of a month. The28 conspicuous constellations and the five withsingle very bright stars are printed in smallcapitals, while the inconspicuous constellationsare printed in small letters. In order to matchthe sky, the chart is supposed to be held overthe head of an observer facing south. Thusfor a convenient hour of the evening, the posi-tion of the constellations is given for everymonth in the year. In order to get the posi-tion at any other hour of the evening, only theapparent diurnal rotation of the heavens needbe taken account of.

Figures i to 24 give the tracings and infor-mation about the 28 conspicuous constellations.Andromeda and Perseus, Aries and Triangu-lum, Libra and Scorpius, Ophiuchus and Ser-pens, are represented by one figure for eachpair. The faint lines represent the tracings.


39/92

LOCATING THE STARS AND CONSTELLATIONS 27The arrow points to the north pole of theheavens, and thus indicates for a constellationin any position how the tracing must be heldto match the sky. Three symbols are used torepresent the stars, depending upon their mag-nitude: -+- for stars having a magnitude of1.4 or brighter; for stars having a magni-tude between 1.5 and 3.4 inclusive; for starshaving a magnitude of 3.5 or less. The desig-nation of the star and its exact magnitudeaccording to the measurements made at theHarvard College Observatory are stated. Theproper name of the star is also given, and itscolor if not white, and, if variable, the limitsof the variation and the period if periodic. Atthe bottom of each figure the right ascensionand declination of the center of each constella-tion are indicated.^

^ Right ascension and declination are the coordinates in theso-called equator system of coordinates. The fundamental pointsof this system are the poles of the celestial sphere, that is, thepoints of no diurnal motion on the celestial sphere. These arethe points where the earth's axis produced cuts the celestialsphere. The north pole is located near Polaris (a Ursae Mi-noris). The celestial equator is a great circle 90" from the pole.It is the great circle in which the plane of the earth's equatorcuts the celestial sphere. The equator runs through the con-


40/92

28 HOW TO IDENTIFY THE STARSThe facts concerning the five constellations

with a single very bright star are:Bootes o; name, Arcturus ; magnitude, 0.2; color,

orange-white.Canes Venatici o; name. Cor Caroli ; magnitude, 3.3

color, white.Canis Majora; name, Sirius; magnitude, 1.6; color,bluish white.Canis Minor a ; name, Procyon ; magnitude, 0.5 ;

color, bluish white. (j8 Canis Minoris has a magnitudeof 3.1 and is fairly conspicuous. The constellation couldperhaps have been represented by these two stars betterthan by a single star.)

Piscis Australiso; name, Fomalhaut ; magnitude, 1.3;color, orange-white.

Of the 19 inconspicuous constellations Can-cer and Cepheus are perhaps the most easilyrecognized. There are two stars in Cepheusstellations of Pisces, Cetus, Taurus, Orion, Monoceros, Hydra,Sextans, Leo, Virgo, Serpens, Ophiuchus, Aquila, Aquarius.The great circles drawn through the poles and perpendicular tothe equator are called hour circles. The starting point or originof coordinates is the vernal equinox, the point where the suncrosses the equator on March 21. It is located in the constella-tion of Pisces. Declination is angular distance north or southof the equator ; plus when north and minus when south. Rightascension is the portion of the equator between the vernal equi-nox and the hour circle through the point in question. It isusually expressed in time and runs from o to 24 hours.


41/92

LOCATING THE STARS AND CONSTELLATIONS 29which catch the eye first and they are quite aHttle brighter than those near them. Theseare a (magnitude 2.6) and /8 (magnitude 3.3).Cancer is noticeable on account of the threestars quite close together which form a littleequilateral triangle.

The best method of building up an acquaint-ance with the stars and constellations from thematerial here given can only be suggested.Most people know at least two or three con-stellations. If that is the case, the best methodof procedure is to study first the constellationswhich surround those which are already known.Notice the tracing, determine where the con-stellation is with reference to those alreadyknown, and then try to pick it out amongthe stars. In this way all of the constellationswill become gradually known. If no constella-tions at all are already familiar to the observer,start with those which are by far the most con-spicuous. These are probably Aries, Auriga,Cassiopeia, Leo, Lyra, Orion, Pegasus, Scor-pius, Taurus, Ursa Major. Determine fromthe charts where the constellation is located,observe carefully the tracing, noting particu-


42/92

30 HOW TO IDENTIFY THE STARSlarly the magnitudes of the stars, and thenpersevere until the constellation is recognized.

For example, if the attempt is to be madeto find the constellation of Taurus, fix firmlyin mind before going out to observe the skythat the tracing is a V, that all of the stars butone are of about the same magnitude and onlymoderately bright, and that the one brightstar is of the first magnitude and reddish incolor. As these facts are sometimes forgottenwhile observing the sky, it is often convenientto take with one the tracings and a pocketelectric lamp for illuminating them.When a beginning has once been made,

progress is usually easy. A single hour's in-struction by one familiar with the stars andconstellations is sufficient to give a considera-ble amount of information to a beginner, par-ticularly if the charts and tracings have beencarefully studied previously.Another method advocated by some forbuilding up an acquaintance with the stars andconstellations is to start with the fifteen bright-est stars. The chief facts about these starshave been given in a previous table. Find


43/92

LOCATING THE STARS AND CONSTELLATIONS 31out, by looking up the constellations on thecharts, how many of these are visible at thedesired time of observation and in what partof the sky they are located. Then persevereas before until these have been recognized,and from these as known points build up anacquaintance with the surrounding stars andconstellations. This method of starting withthe bright stars can be used to the best ad-vantage when the moon is from three to sevendays old. The light of the moon pales outthe fainter stars, thus making the bright onesmore conspicuous. A perfectly clear moon-less night is not the best time to begin ob-servations, as the number of stars visible isconfusing.Some advocate trying to locate the stars

and constellations by identifying them whenrising or setting. The disadvantages of thismethod are that the horizon is always morehazy and cloud-covered than the rest of thesky, and, secondly, that it confines the timeof observation to a particular hour of thenight and is impossible at some times ofyear.


44/92

32 HOW TO IDENTIFY THE STARSAny attempt to locate a star or constellation

by giving its direction and distance from aknown point will be no more successful thanto notice its location on a chart.


45/92

VIII. THE METHOD OF FURTHERSTUDYThe charts, figures, and information given

above can serve only as a guide in taking thefirst steps in learning the stars and constella-tions. Further knowledge is both useful andpleasant, and to gain it the reader must bereferred to the numerous books bearing on thesubject. Some of these books will be indi-cated here.ALLEN, Star-names and their Meanings;

G. E. Stechert, 1899, is a veritable mine ofinformation. It gives the meaning of thenames used in connection with the stars andconstellations, numerous extracts from the writ-ings where these names were used, and themore important facts such as magnitude, color,etc., about the chief stars in each constellation.It is a compendium of information, but not abook to be read through as a whole.There are two books, MARTIN, The

Friendly Stars; Harper and Brothers, 1907,D 33


46/92

34 HOW TO IDENTIFY THE STARSand SERVISS, Astronomy with the NakedEye; Harper and Brothers, 1908, which at-tempt to put in readable and attractive formthe facts concerning the stars and constella-tions. The last-named book also contains starcharts, giving the position of all stars down tothe sixth magnitude. These are the two booksto recommend whenever a book giving a popu-lar presentation of the subject is desired.Among the modern up-to-date star atlases

may be mentioned:BALL, A Popular Guide to the Heavens; George Philip& Son, London, 1905.KLEIN, Star Atlas; E. & J. B. Young & Co., New York,

1901.PECK, The Observer's Atlas of the Heavens; Gall &

Inglis, London, 1898.UPTON, Star Atlas; Ginn & Company, 1896.MESSER, Stern-Atlas fiir Himmelsbeobachtungen ; K.

L. Ricker, Leipzig, 1902.

A star atlas is absolutely essential to one whodesires to add to his knowledge of the starsand constellations. The star charts in theseatlases represent all the constellations withtheir boundaries, and give the location of allstars visible to the naked eye. In addition


47/92

THE METHOD OF FURTHER STUDY 35much information is given concerning starmagnitudes, double stars, variable stars, starcolors, etc. The meaning of the names, how-ever, and the historical side of the subject areusually not treated. If it is desired to identifyan unknown star, the best method is to esti-mate its magnitude carefully, and note its loca-tion with reference to several known stars orconstellations. A chart of this portion of thesky may then be consulted, and the unknownstar can usually be readily identified and theconstellation to which it belongs determined.If it is desired to locate an inconspicuous staror constellation, the best method is to note onthe appropriate chart its location with refer-ence to several easily identified stars or con-stellations. On turning to the sky the incon-spicuous object can usually be readily locatedand identified. In this way, by means of staratlases, one's information may be indefinitelyextended.Such atlases as ARGELANDER'S Atlas

des N'ordlichen Gestirnten Himmels (2d edi-tion by'Kustner, Bonn, 1899), PETERS'SCelestial Charts (published at Canton, N. Y.),


48/92

36 HOW TO IDEXTIFY THE STARSand the Uraiurmetria Argentina are usefulonly in connection with the telescope when itis desired to identify all the stars, perhapseven to the ninth or tenth magnitude, withina very small area such as the field of \iew ofthe telescope.

Lists of the constellations, the stars ^asibleto the naked eye, colored stars, ^'ariable stars,etc., can also be found in CHAMBERS'SHandbook of DescHptive and Practical As-tronomy (The Clarendon Press, 1890) andVALEXTIXER, Handw'orterbuch der As-tronomic (Breslau, 1901).

If the coordinates of a star, right ascension,and declination are desired, they may be foundfor a small selected list of stars in Tlie Ameri-can Epiiemeris and Nautical Almunac, pub-lished each year at \\'ashington, or in the cor-responding year books of the English, French,and German governments. AMBROXX,Sternverzeichnis (Julius Springer, Berlin, 1907)also contains the coordinates of aU stars (7796in all) which are above the 6.5 star magnitude.Such information, however, is desired not bythe observer who is locating an object by


49/92

THE METHOD OF FURTHER STUDY 37means of the stars, but by the computer whois reducing the observations.The following list contains other valuable

books on the stars and constellations:BURRITT, Atlas designed to illustrate the Geography

of the Heavens; New York, 1835.COTTAM, Charts of the Constellations ; London, 1889.DIEN, Atlas Celeste; Paris, 1869.GORE, Star Groups; Crosby Lockwood & Sons, Lon-

don, 1 89 1.HEIS, Atlas Coelestis Nouvus ; Cologne, 1872.HILL, The Stars and Constellations ; Funk & Wagnalls

Company, New York, 1894.JEANS, Handbookfor Finding the Stars; London, 1888.JOHNSTON, School Atlas of Astronomy (revised by

Grant) ; G. P. Putnam's Sons, New York.MAUNDER, Astronomy without a Telescope; London,1902.PECK, The Constellations and how to find them; Gall& Inglis, London.PORTER, The Stars in Song and Legend; Ginn & Com-

pany, New York, 1902.PROCTOR, Half-hours with the Stars; G. P. Putnam's

Sons, 1875.SERVISS, Pleasures of the Telescope; D. Appleton &

Company, New York, 1905.SERVISS, Astronomy with an Opera-glass; D. Apple-

ton & Company, New York, 1906.YOUNG, Uranography, in his Elements of Astronomy;New York, 1890.


50/92

38 HOW TO IDENTIFY THE STARSThe star atlases of Burritt, Heis, and Dienare particularly interesting, as they give greatprominence to the constellation figures, as wasthe case with all the older atlases.


51/92


52/92


53/92

April 1st, 9 p.m.

'HERCULES

CHART II.

N

Ceptiens

March 1st, 11 p.ra.May Isl, 7 p.tn.

CASSIOPEIA(pole)m PERSEUSDRACOCORONA URSA CamelopardaUsBOKEALIS MINOR

BOOTES URSA MAJOR AUHIGA


54/92


55/92

CHART III.July 1st, 9 p.m. N

June Isl, 11p.m.Au&ust 1st, 7 p.m.

XacertaCASSIOPEIA . camelopardalis

{pole, Lynj.Cepbeas UKSA MTNORUESA MAJOR

CYGNUSDRACOLYBADKLPHINUS

,, , , (zenith)Vulpecula HjjjcULES SACilTTA ^CORONA

AQmLA BOKEALIS

Leo MinorCANESTENATICI

BOOTES ComaBerenices

w

ScutumSAGITTARIUS


56/92


57/92

CHART iv:


58/92


59/92

PERSEUS


60/92


61/92

Fig. 3

Fig. 4


62/92


63/92


64/92


65/92

Fig. 7

Fig. 8


66/92


67/92

Fig. 9

Fig. io


68/92


69/92

1.6a^


70/92


71/92

Fig. 13

SCORPIUS

a Antares RW16y2 h. 26

Fig. 14


72/92


73/92

Fig. is


74/92


75/92

Fig. 17

PEGASUS2.1 aAnd. /

//

/

(


76/92


77/92


78/92


79/92

TAURUS

o Aldebaran RW4M h. 18-Fig. 21

URSA MAJOR

a Uubhcf Mizar

c Aliotho^ Alkor

Fig. 22


80/92


81/92

Fig. 23

Fig. 24


82/92


83/92

BOOKS FOR THE GENERAL READEROF SCIENTIFIC TASTESAvebury's Peace and Happiness

By the Right Honorable Lord Avebury, P.C. {^formerly Sir John Lubdock),i2mo. Cloth, 3g6 pages. $i.joet.

Simple, sensible advice on such topics as the proper treatment of the body andthe mind, on education, on our attitude towards children, friends, and enemies,on riches, on nature and religion.Bailey's The Evolution of Our Native Fruits

By L. H. Bailey. i2mo. Cloth. Illus. ^yspages. $2,00 Tiet.In this entertaining volume, the origin and development of the fruits peculiarto North America are inquired into, as well as the personahty of those horti-cultural pioneers whose almost forgotten labors have given us our most valuablefruits.

Bailey's The State and the FarmerBy L. H. Bailey, ismo. Cloth. i8g pages. $1.2; net.

A book discussing the political and economic status of the farmer. Of particu-lar interest not only to the agriculturist but also to the student of economicsand to the general reader.Bailey's The Survival of the UnlikeA Collection 0/Evolution Essays suggested by the Study ofDomestic Plants.

By L. H. Bailey, ^i^pages. $2.00 net.This work treats the modification of plants under cultivation, and incidentallygives much that is suggestive and valuable to the working horticulturist.Ely's A Woman's Hardy Garden

By Helena Rutherfurd Ely. With illustrations from photographs. i2mo.Cloth. 2^1 pages. $r.y^net.

Ely's Another Hardy Garden BookBy Helena Rutherfurd Ely. With illustrations from photographs. i2mo.Cloth. 258pages. $l.y5 net.

"Mrs. Ely is the wisest and most winning teacher of the fascinating art ofgardening that we have met in modern print." New York Tribune.French's A Book of Vegetables and Garden HerbsA Practical Hand-book and Planting Tablefor the Home Garden. By Allen

French. i2mo. Cloth. Illus. jj8pages. $i.js net.Hall's Three Acres and Liberty

By Bolton Hall. i2mo. Cloth. Illus. 4;^pages. $1.7; net.Possibilities of the small suburban farm, and practical suggestions to city dwell-ers how to acquire and make profitable use of it.Harwood's New Creations in Plant LifeByW.S. Harwood. i2mo. Cloth. Illus. 43^ pages. $i.-^snet.This is the first authentic account of the really wonderful experiments with plantlife conducted by Mr. Luther Burbank in California.Harwood's The New EarthA Recital of the Triumphs of Modern Agriculture in America. By W. S.Harwood. izmo. Cloth. Illus. sqopages. $/.ys net.


84/92

Hutchinson's The Story of the HillsA Book about Mountainsfor General Readers. By Rev. H. W. Hutchinson.i2mo. Cloth, lllus. jy2fages. $1.50."A clear account of the geological formation of mountains and their variousmethods of origin in language so clear and untechnical that it will not confuseeven the most unscientific," Boston Evening Transcript.Illinois Girl's A Prairie "WinterBy an Illinois Girl. Cloth. 164pages. $1.00 net.A record of the procession of the months, from midway in September to mid-way in May.Ingersoll's The Life of Animals : The MammalsBy Ernest Ingersoll. With Fourteen Full-page Color Plates and Many Other

Illustrations. 8vo. Cloth. 566 pages. $2.00 net." Each of the groups of mammals from the highest to the lowest is taken up inturn with illustrations, descriptions, and anecdotes of some of the representa-tives. Many of the illustrations are from original photographs and drawings,and greatly enhance the value of the work." American Journal of Scieiice, New Haven.Ingersoll's Wild Neighbors

Outdoor. Studies in the United States. By Ernest Ingersoll. With Numer-ous Illustrations. i2mo. Cloth. 313pages. $1.50.Studies and stories of the gray squirrel, the puma, the coyote, the badger andother burrowers, the porcupine, the skunk, the Woodchuck, and the raccoon.McFarland's Getting Acquainted with the TreesBy J, Horace McFarland. 8vo. Cloth. lllus. 1^0pages. $1.^0 net.Marble's Nature Pictures by American Poets

Selected and Edited by Annie Russell Marble. i2mo. Cloth. 248 pages.50 cents net.Mead's Irrigation InstitutionsA Discussion ofthe Economic and Legal Questions created by the Growth ofIrrigated Agriculture in the West. By Elwood Mead. i2mo. Half

leather. 403pages. $1.2^ net.This book is based upon twenty years' experience in the development of irri-gated agriculture in the West under conditions, oihcial and otherwise, whichgave unprecedented opportunities for information and judgment.Peterson's How to Know the Wild FruitsA Guide to Plants when not in Flower, by Means of Fruit and Leaf. ByMaude Gridley Peterson. Illustrated by Mary Elizabeth Herbert. J2mo.Cloth. 482pages. $r.jo net.

Scott's The Story of a Bird LoverBy William Earl Dodge Scott. i2mo. Cloth. lllus. 383pages^ $1.50net." There is charm in the manner of the telling of this bird-lover story whichmakes it appeal not alone to him who has scientific names at his tongue's tip,and who knows the nesting day of every bird in the ornithological list, but tohim as well who has simply the layman's love for a breezy narrative and for thatfreshness which comes from a well-told tale of the free fields." Chicago Evening Post.


85/92

Sheldon's The Farm and the DairyByJ. p. Sheldon, ismo. Cloth. Illus. i66pages, $i.oonei.

A valuable text-book on practical dairying, detailing the most modern develop-ments in dairy farming.Smythe's The Conquest of Arid America

By William B. Smythe. 8vo. Cloth. Illus. ^opages. $1.50 net.Mr. Smythe discusses colonization and irrigation in a general way, and theintervention of the Government in the task of reclaiming the desert parts of ourtountry.

St. Maur's A Self-Supporting HomeBy Kate V, St. Maur. i2mo. Cloth. Illus. 3^6pages. %I.'J5 net.

Each chapter is the detailed account of all the work necessary for one monthin the vegetable garden, among the small fruits, with the fowls, guineas, rabbits,

I'cavies, and in every branch of husbandry to be met with on the small farm." One of the most sensible, practical books of the kind ever published." Louisville Courier-Journal,St. Maur's The Earth's Bounty

By Kate V. St. Maur. 438pages. $i.ys net.Written in the same practical, sensible, and thoroughly interesting vein as thepreceding, but touching a wider range of farm activities.Streeter's The Fat of the Land

The Story 0/an American Farm, By John Williams Streeier, ismo. Cloth,4iypages. $1.50 net.

Weed's Life Histories of American InsectsBy Clarence Moores Weed. i2mo. Cloth. Illus. 2^pages. $1.50 net.

In these Jfeges are described by an enthusiastic student of entomology suchchanges as may often be seen in insect form, and which mark the progress ofits life.

White's Natural History of SelborneBy Gilbert White, Edited iy C, Weeks, i6mo. Cloth. 388pages, ^o cents;leather ^ 75 cents,

Wright's BirdcraftA Field Book ofTwo Hundred Song, Game, and Water Birds. By MabelOsgood Wright. With Eighty Full-page Plates by Louis Agassis Fuertes.i2mo. Cloth. 33gpages. $2.00 net.

"The author is not a hard-hearted seientist who goes forth with bag and gunto take life and rob nests, but a patient and intelligent observer who loves thechildren of the air, and joins their fraternity,"New York Observer.Wright's Flowers and Ferns in Their Haunts

By Mabel Osgood Wright. With Illustrations from Photographs by theAuthor and J. Horace McFarland. i2mo. Cloth, ^jypages. $2.30 net." I did not come to pull to pieces or transplant," says the author in the firstchapter of this most delightful of outdoor books.Wise's Diomed

The Life, Travels, and Observations of a Dog. By John Sergeant Wise,Illustrated by J, Linton Chapman. i2mo. Cloth. 3'j'j pages. $l.;onet.

" One of the best dog stories we know, and the pictures are beautiful, rare fortheir delicacy and expressiveness, and for their truthfulness to the personalityand environment of the dog." The Literary World.


86/92

Professor Lowell's Notable Study of MarsMars as the Abode of Life

The book is based on a course of lectures delivered at theLowell Institute in 1906, supplemented by the results of laterobservations. It is, in the large, the presentation of the resultsof the author's research into the genesis and development ofwhat we call a world ; not the mere aggregating of matter, butthe process by which that matter comes to be individual as wefind it. He bridges with the new science of planetology theevolutionary gap between the nebular hypothesis and the Dar-winian theory.It was during the delivery of this series of Lowell Lectures thatthe Listener in the Boston Transcript described his reasoningas " racy, brilliant in style, daring in imagination, building aconvincing thesis."

By the Same Author Previously PublishedMars and Its Canals" The book makes fascinating reading, and is intended for theaverage man of intelligence and scientific curiosity. It repre-sents mature reflection, patient investigation and observation,and eleven years' additional work and verification. ... It isthe work of a scientist who has found inspiration and joy in hiswork ; it is full of enthusiasm, but the enthusiasm is not allowedto influence unduly a single conclusion. . . . The book is fullof quotable sayings and delightful things. . . . We have herescience, reality, that is infinitely stranger and more thrillingthan the most imaginative fiction." Chicago Evening Post.Each is illustrated with reproductions of exceptional photo-graphs, some of them in colored plates.

Price of each, $2.30 net; by mail, $2.jo.PUBLISHED BY

THE MACMILLAN COMPANY64-66 Fifth Avenue, Hew York


87/92


88/92


89/92


90/92


91/92


92/92

Documents

How to Identify the Stars