Celestial Objects for Common Telescopes
Total Page：16
File Type：pdf, Size：1020Kb
Wis€ rca^iwg hadelhtoh^kevhveh^ arid lofarkhep skores ^^sys^'sysysysys ,^i^; Mfii u£l Ex I Types ol" Stellar Spectra according to Secchi. ccT'dim 11.111. (xHerculis Es-Birm 36^ w. Oi^ang'e Yellow ndigo | | From vol VIII ophe Publications of the Kiel Observatory. CELESTIAL OBJECTS FOE COMMON TELESCOPES BY THE REV. T. W. WEBB, M.A., F.R.A.S. VICAR OF HARDWICK, HEREFORDSHIRE FIFTH EDITION, REVISED AND GREATLY ENLARGED BY KEV. T. E. ESPIN, M.A., F.R.A.S. IN TWO VOLUMES VOL. II. LONDON LONGMANS, GREEN, & CO. AND NEW YORK: 15 EAST 16"^ STREET 1894 All rights reserved ' %l^%\ Many things, deemed invisible to secondary instruments, are plain enough to one who ' knows how to see them Smyth When an object is once discovered by a superior power, an inferior one will suffice to see it afterwards Sir W. Heeschkl Inertia mors est philosophise—vivamus nos et exerceamur Kepler Pulchra sunt omnia faciente Te, et ecce Tu inenarrabiliter pulchrior, qui fecisti omnia S. Augustine Sic enim magnalia sapientise suse decoravit Is, qui est ante sa?culum et usque in sasculum; nihil redundat, nihil deficit, nee locus est censuraj cujusquam. Quam desiderabilia opera ejus !***** et quis saturabitur videns gloriam eorum ? Kepler 2 CONTENTS Part III. The Starry Heavens. PAGE Introduction : Double Stars, IV CONTENTS. PAGE Appendix I. Starless Fields ...... 253 „ II. Southern Stellar Objects .... 253 „ III. Note on the Distribution of Stars in Space 264 „ IV. Additions and Corrections .... 266 Index to Double Stars having no Greek Letter or Number in Bayer and Flamsteed .... 269 „ TO Stars of Es-Birm ...... 277 „ to Nebula ........ 279 Illustrations. Map of Star Spectra Frontispiece Diagram of Telescopic Field page 10 DiAGRAjji of U Ce^hei „ 80 Spectrum of Mira Ceti . „ 85 The Hercules Cluster . M 136 — : PAKT III. THE STARRY HEAVENS. Lift up your eyes on bigb, and behold Who batb created these thing?, that bringeth out tlieir host by number : He calleth them all by names by the greatness of His might, for that He is strong in power ; not one faileth. Isa. xl. 26, DOUBLE STABS, CLUSTEBS, AND NEBUL2E. If the Solar System had comprised iu itself the whole material creation, it would alone have abundantly sufficed to declare the glory of God, and in our brief review of its greatness and its wonder we have seen enough to awaken the most impressive thoughts of His power and wisdom. But that system is but as a single drop in the ocean. What boundary may be set to creation we know not, but we can trace it sufficiently to perceive that, as far as our senses are concerned, it cannot be distinguished from absolute infinity and in leaving our Sun and his attendants in the background, we are only approaching more amazing regions, and fresh scenes will open upon us of inexpressible and awful grandeur. We are now to contemplate not one Sun, but thousands and myriads : not a planetary system of subordinate globes,— but pairs, groups, galaxies of Suns ' the aggregations of Suns ; host of heaven ' —all independent in unborrowed splendour, VOL. II. B 2 THE STARRY HEAVENS. yet many evidently, and aH by clear implication, bound together by the same universal law which keeps the pebble in its place upon the surface of the earth, and guides the falling drop of the shower, or the mist of the cataract. Many of these Suns may probably be smaller or dimmer than our own, yet others unquestionably far surpass his splendour ; while as to distance, their remoteness is so in- conceivable that light itself, flying with a speed which would encircle the Earth nearly 8 times in one second, only shows them to us as they formerly were, some years, others centuries, others perhaps whole ages back, even in the first dawn of creation. Here is indeed a field where enterprise cannot be thrown away, nor perseverance fail of its reward. We must, however, remember that, though they are Suns which we are contemplating, and though the mere aspect of some of them in a large telescope well bears out the assertion,^ yet a great proportion are diminished by distance to the minutest points of light, and can only be distinctly seen under favourable circumstances. We cannot therefore expect uniform success ; in fact, the more delicate objects of stellar astronomy are not only among the severest tests of the telesco]3e and the eye, but are peculiarly liable to be afi'ected by atmospheric indistinctness, and require the most propitious skies. The cautions suggested in Part I. will be especially applicable here. An original investigation of all the objects worthy of notice, even in a popular sense, in the starry heavens, would * The approach of Sirius to the field of H 40-ft. reflector is said to have been ushered in by a dawning light, and its actual entrance to have been almost intolerable to the eye: yet the 4-ft. mirror was far from good. "What must be the blaze of this star in the Earl of Rosse's telescope, with a speculum of 6 ft., of much higher reflective power! DOUBLE STARS, CLUSTERS, AND NEBULA. 3 have been the attempt of a lifetime, rather than of such occasional hours of leisure as I could command: an un- verified selection, on paper, from a standard list formed with a very different design, would have been an easy, but not a satisfacjjory task : a middle course has therefore been pre- ferred. All such of the 850 Double Stars and Nebulas of Vice-Admiral Smyth's Bedford Catalogue as my SyVi^- ^^ aperture could be expected to reach, were examined in succession,^ and those only retained which seemed to possess sufficient general as well as scientific interest, and might serve as sj^ecimens of the universal profusion: but as in such a review a number of other objects, beautiful to the popular eye, though unimportant perhaps to the professed astronomer, presented themselves unsought, many of these have been added to the list, as well as many from Struve's ' Mensurse Micrometricae,' and other quarters. Such was the plan of the preceding edition. But the seven years ,that have since elapsed have brought such an unprecedented increase of observers and instruments competent to deal with a more difficult class of objects, that it has been thought desirable, without abandoning the original design or title of the work, to enlarge it in the hope of greater usefulness. An addition has accordingly been made of about 1080 pairs from Lord Lindsay's very valuable Summary of the Dorpat Catalogue, together with 70 from that of Poulkova, and many from the lists of Burnham.^ ^ In the present edition the colours taken from Mr. Webb's Manuscript Observation are inserted after those of 2, and the date is added thus : —y w., blsh., '49. 2 In the present edition an attempt has been made to complete the list of Double Stars to a certain magnitude. All Double Stars whose primary is above 6-5 (according to the authorities whence the information is taken), and their distances less than 20" Lave been 4 THE STARRY HEAVENS. The series comprises many notes on colour and magnitude, the iDormitted publication of which demands special ac- knowledgment. These may all in their way be helpful to the student. But, if diligent in the employment of oppor- tunities, he will soon find that, as these pages ar^ but a very limited selection from works of the highest character, so those in turn are powerless to rej^resent even what we can reach of the unspeakable richness and grandeur of the firmament. The Dorpat Catalogue of 3062 double stars was a wonder of accuracy and perseverance : but h. considered that it included less than l of the pairs that were obvious in his sweeping: and a large proportion of these are un- recorded still. And yet the sole, or even the chief attraction of the sidereal heavens does not lie in the juxtaposition of two stars, possibly merely accidental, and frequently beyond the reach of any but the most powerful instruments. Many parts of the sky, especially the crowded fields of the Galaxy, are full of most interesting and beautiful groups and combi- nations, of which little or no mention can be found. The attention of the professed astronomer is usually directed into some definite channel, and he has little leisure, and some- times perhaps not much taste, for that general and indefinite sweeping and ' star-gazing,' which to humbler students becomes a source of boundless delight and wonder. It need not be said that the wishes of the latter class have been chiefly considered in the following pages, though it is hoped they may be of occasional use in other ways. From a pressure of various employments, the interval since the first appearance of this little work has not added much original matter to the following catalogue. But it is to be hoped that some zealous lover of this great display of added as far as they could be found in the great mass of Double Star Observations now published. DOUBLE STARS, CLUSTERS, AND NEBULA. 5 the glory of the Creator will carry out the author's idea, and study the whole visible heavens from what might be termed a picturesque point of view. This would involve nothing more than a sufficiency of optical power, of leisure, and of patience bringing with it its abundant reward. By a suitably arranged plan, every part of the sky might be swept over in succession, and the principal instances of intensity of colour, or elegance or singularity of grouping having been noted, the materials would be prepared for a most interesting work— a Handbooh of the Wonders and Beauties of the Sfarnj Heavens.