ASTRONOMY. 



CHAPTER VII. 

 ON THE CONSTELLATIONS AND FIXED STARS 



Oc* pwnent arrangement of the constellation* into 

 groups or clusters, representing figure* of m. n :>il 

 animals, date* from the moot remote nntii|iiit y '-. 

 a Cilician of Eudoxus, B.C. 370, a contemporary of IM:itn, 

 enumerates forty-five as being then in use, all i>f which 

 still remain on our celestial globes. In tin- majority of 

 instances, however, there is no similarity between these 

 configurations, and the figures to which they are sup- 

 posed to bear some resemblance. Of the fixed stars, in 

 both hemispheres, nearly 5,000 are visible to the naked 

 eye, the greater number of which have been catalogued 

 by Argelander, in his standard work, the Manotn 

 Jvora. They are divided into classes of magnitude, the 

 Jint consisting of stars pre-eminently bright, and whieh 

 amount in our latitude to about 14 ; the second magni- 

 tude ei insisting of about 50 ; the third of 140 ; the fourth 

 of about 320 ; the fifth of 800 ; and the sixth of 2,000 

 (roughly speaking). Objects of a magnitude greater in 

 class, but apparently less in size than the sixth, are only 

 seen by the help of telescopes, and are reckoned on to 

 the thirteenth or fourteenth magnitude. 



Bayer appears to have been the first astronomer who 

 systematically arranged the stars of each constellation in 

 the order of magnitude. In his catalogue, of which the 

 epoch is 1603, he classed the brightest stars in each 

 constellation according to the first letter of the Greek 

 alphabet; the second by the second letter, and so on ; 

 afterwards using for smaller objects the Roman letters. 

 Of the first magnitude in these latitudes, we have wine 

 north of the equator, and five south, viz. : 



Forth. 



Vega, or a Lyrsa 

 (.'apella, or a AurigfB 

 Arctunis, or a Bootis. 

 Aldebarau, or a Tauri. 

 Betelgeux, or a Orionis. 



South. 



Regulus, or n Tx'onis. 

 Altair, or a Ai|iiilii:. 

 Deueb, or n L'yirni. 

 Procyou, or a (J.uiU 

 Minoris 



An tares, or a Scorpio. 



Foinalhaut, or a 1'iscis, 

 Australia. 



S i ri us, or a Canis Majoris. 



I, or ft Orionis. 

 Spica, or a Virginia. 



Bayer's arrangement has since been used byast 



The most ancient catalogues we possess of the fixed 

 stars are those of Ptolemy, Ulugh Beigh, Tycho, and 

 llevelius, all of which have been formed from observa- 

 tions by the naked eye. The catalogue of Ptolemy is 

 based on the observations of Jlipparchus, and amounts to 

 upwards of 1,000, which are arranged in the order of 

 longitude ami latitude. That of Ulugh Heigh contains 

 1,019 stars for the ejMH'li of 1 C>7, observed at Sainarcand 

 in Persia, north latitude 39 ' n'2'. The epoch of Tyeho 1 * 

 catalogue is for the end of the sixteenth century, and 

 contain* 777 stars, n-dmvd and edited by his pupil, 

 Kepler. The catalogue of llevelius contains l.'ii'a posi- 

 tions of stars for the epoch llillH. All tile plveedll. 

 have been re-edited by Mr llaily. to whom this bram-h 

 of astronomy is much indebted, and are given in the 

 .th volume of the M, ut"iri of the Jtinjat Attro- 



> t </. 



Since the application of the telescope to astronomical 

 observations, we have the catalogue* of 1 1. ill. \ and l,i 

 Caille, observed in the southern hemisphere; and those 

 of Flamsteed, Bradley, and Mayer, observed in the 

 European observatories. The work of Flamsteed is the 

 basis of that of Bradley, and they both, in common, con- 

 tain nearly the same stars, but, in I he latter case, observed 

 with more improved instruments. The numbers in the 

 catalogues of Flamsteed, Bradley, and Mayer, are re- 

 spectively 3,4011, 3,222, and '.I'M stars. 



At the commencement of the present century we pos- 



sessed the catalogues of Groombridgo, Piajtzi, and La- 

 lande, of which the first consists of circumpolar stars 

 numbering upwards of 4,000 ; the second of 7,646 itars ; 

 and the last of 50,000 stars. 



In modern times we have the catalogues of I'.u-lrim 

 and Taylor, observed at New South Wales and Madras 

 respectively ; the Greenwich catalogues of Pond and 

 Airey ; and the continental liker, 



Bessel, and A rj. Kinder. The British Association have 

 also published a st.ui.ianl catalogue of 8,377 stars. 



THK /..in | are twehe in number, 



all of which occur in the list prepared by A rat us. 



I. .-/ /-!.< has tivo very conspicuous stars in the head of 

 the Ram, about 4 apart. They are the, nautical star, a 

 Arietis, called II until by the Arabs, of the second magni- 

 tude, and Sheratan, of the third. 



I I. 7'nuriu, one of the finest of zodiacal Asterisms, is 

 just rising in the east when Aries is 27 above the horizon. 

 It includes Aldebaran, a star of the first in form- 



ing with Hyades the letter Y in the face of the Bull ; 

 on the left shoulder is the well-known cluster of the 

 I'leaides. 



III. '/. mini has two principal stars, Castor of the first, 

 and Pollux of the second magnitudes, about 4)i J apart, 

 iii the neighbourhood of Propus, a small star of the fifth 

 magnitude. In this constellation Sir John Herschel 

 found \ ranus. and it served for many years to guide 

 astronomers to that planet. 



I V. ( 'tuirtr has no very conspicuous star. Two of the 

 fourth magnitude, the Asolli (the Asses) of the I;.. mans, 

 and I'rescpe (the .Manner). A nebulous cluster, at the dis- 

 tance of 2i , distinguishes this constellation. 



V. Leu, a brilliant constellation, has Hegulus, of the 

 first magnitude, in the breast of the Lion, and Denebola, 

 of the second magnitude, in the tail, about 25 apart. 



VI. Virgo has Spica Virginia, a star of the fourth mag- 

 nitude, in the Wheat-ear, remarkable for its solitary 

 splendour, having only one other star, of the fourth mag- 

 nitude, near it. This star is called Al-timuk-al-a-zal 

 (the Defenceless) by the Arabs. 



VII. Libra has four subordinate but bright stars, which 

 form a quadrilateral figure. Two in the northern and 

 two in the' southern scale, 7 and apart. 



II 1 1. Scorpio is a beautiful collection of stars, among 

 which Antares (in the heart) is of the first magnitude, 

 ami is distinguished by a remarkably red appearance. 



IX. Hiiytttiirha has five stars of the third and fourth 

 nri'jmtndcs, which form a figure resembling a straight- 

 handled dipper, familiarly called the milk-dipper, because 

 situated in the Milky Way. 



X. Capricornus has only stars of the third and fourth 

 magnitudes. The sun was formerly in this constellation, 

 when at mid-winter he attained his greatest southern 

 declination ; hence it was called the southern gate of the 

 sun, as Cancer was the northern. Now, owing to the 



-siou of the equinoxes, the sun does not reach the 

 constellation till the middle of January. 



XI. Aquar\\a is recognisable by four stars of the fourth 

 magnitude, so placed as distinctly to form the letter Y, 



i is visible about the uni of the Water bearer. 

 X 1 1. Piscet is a loose assemblage of small stars, not 

 i. .1 ddy traced, occupying a large triangular space in the 

 heavens. This is the ficst constcllati..n in the order of 

 the zodiac, opening the astronomical year, and preceding 

 our vernal equinox. 



In naming and figuring these zcxliacal groups, the 

 ancient* are supposed to have been guided by the rural 



itions coincident with the sun's appearance in 

 particular parts of the heavens, or by other analogous 

 phenomena presented to them. Thus, the RAM, the 

 BULL, and the TWIMS (originally two goats), relate to 



