56 



ASTRONOMICAL PROGRESS AND PHENOMENA. 



ables and suspects (the latter published since 

 the issue of last year's "Annual Cyclopaedia") 

 are the work of Mr. J. E. Gore, of Ireland. 

 The suspected variables, 745 in number, are 

 arranged in the order of right ascension, and 

 are accompanied by particular descriptions. He 

 classifies them into five divisions, as follows: 

 Class 1. Temporary stars. Class 2. Stars under- 

 going larger variations during several months. 

 Class 3. Irregular variables undergoing but 

 slight changes of brightness. Class 4. Varia- 

 bles of short period like /3 Lyra, 8 Cyphei, etc. 

 Class 5. Stars of the Algol type undergoing 

 periodical changes lasting but a few hours. 

 Some of these he divides into sub-classes. The 

 variable star V Cygni, discovered by Birming- 

 ham, has recently been added to the list, and 

 proves to be remarkable, as the following light 

 variation will show: May 13, 1882, = 8 mag- 

 nitude. Oct. 19, 1882, = 9J magnitude. May 

 5, 1883, = 12 magnitude. May 27, 1883, = 

 12 magnitude. July 26, 1883, = 8 magni- 

 tude. Sept. 19, 1885, = 11 magnitude. Sept. 

 29, 1885, = 11 magnitude. Oct. 26, 1885, = 

 10 magnitude. Its color is red, and it is 

 situated 2 51' 42" north of a Cygni. 



Discovery of Nebulae. After the discovery of 

 the immense number of nebula by Sir William 

 Ilerschel, and later by his son, Sir John Her- 

 schel, the subject received little attention until 

 taken up by D' Arrest, Schultz, Lassell, Rosse, 

 and others. Since then, until revived by Messrs. 

 Stephan and Swift, it had fallen into neglect. 

 Their conjoined discoveries amount to over one 

 thousand. It seems useless to speculate upon 

 the origin and design of such immense vol- 

 umes of matter in comparison with which the 

 space circumscribed by Neptune's orbit is puny. 

 The list of M. Stephan, of Marseilles, France, 

 has been given to the public through various 

 channels, such as the u Astronomische Nach- 

 richten " and the " Monthly Notices of the 

 Royal Astronomical Society of England." A 

 partial list all he had discovered up to 1873 

 is to be found in Dreyer's "Supplement to 

 Sir John Herschers Catalogue of Nebulae." 

 Those discovered by Dr. Swift, at the Warner 

 Observatory, Rochester, N. Y., have been pub- 

 lished in five catalogues (one in 1885, and the 

 succeeding four in 1886), of one hundred each, 

 in the " Astronomische Nachrichten." Their 

 positions are approximately given, accompa- 

 nied by descriptive remarks. But two of the 

 whole number may be seen with a 4^ inch 

 telescope. Most of them are as faint as the 

 faintest of Herschel's Class III, and some are 

 still fainter. These discoveries contradict the 

 heretofore expressed opinion that a quest for 

 new nebulas must result only in time lost. 

 Swfft's list affords but few with striking char- 

 acteristics, as might be expected of objects so 

 excessively faint and difficult to see. Only a 

 few require special mention. One is in Mono- 

 ceros, R. A. 6 h 24 m - 11'-, Dec. + 5 7' 32", 

 close to the cluster HVII, "General Cata- 

 logue," 1424. This peculiar object was picked 



up many years ago with a 4^-inch refractor. 

 It is, except the great nebula in Orion, the 

 largest one visible from this latitude, and for a 

 while was thought to be a glow from the 

 above-named cluster. The annexed list com- 

 prises all the nebulous stars proper of the five 

 catalogues : 



The size of these atmospheres is at least ten 

 times that of Neptune's orbit, and probably 

 much greater. The exact centralization of the 

 stars makes it very improbable that their posi- 

 tions are accidental. Two hundred and seventy- 

 three new nebula3 have been recently discov- 

 ered at the Leander McCormick Observatory, 

 University of Virginia, by Prof. Ormond Stone. 

 For a year or two past the six-foot reflector of 

 the Earl of Rosse has been used in the study 

 of photometry and lunar heat instead of in 

 nebular work. 



Variability of Nebulae. A very few nebulse 

 have been suspected of variability, but, in 

 almost every instance, the supposed change has 

 been traced to errors of observation, impurity 

 of the atmosphere, or other causes. There are, 

 however, two cases (both in Taurus) where 

 the evidences of variableness appear to be 

 beyond controversy. The first is the very 

 small nebula about 1^ from e Tauri, discov- 

 ered in 1852 by Dr. Hind. It was about 1' in 

 diameter, with a central condensation of light. 

 On Oct. 3, 1861, D' Arrest found that the 

 nebula had totally disappeared a statement so 

 improbable as to be discredited. It was, in 

 January, 1862, unsuccessfully sought for both 

 by Leverrier at Paris and by Secchi at Rome, 

 though by the following March it had so far in- 

 creased in brightness as to be easily seen. An- 

 other instance has recently come to light of a 

 nebula near Tauri (not Messier I) under- 

 going changes. It was observed by Chacornac 

 at, Paris, near the close of 1885, surrounding a 

 star of the eleventh magnitude, which he and 

 others had repeatedly observed in 1854, and 

 which had also been observed at Markree in 

 1850, without any apparent nebulosity. In 

 1856 Chacornac found the nebula very bright, 

 but in 1862 every trace of it had disappeared, 

 nor has it since been seen until recently (in 

 March, 1885), when it was rediscovered by 

 Mr. Tarrant with a 10-inch reflector and veri- 

 fied by Chacornac. 



Astronomical Prizes. Since the "Annual Cy- 

 clopaedia" for 1885 went to press, the Lalande 

 prize of 540 francs has been awarded to M. 

 Thollon, for his map of the solar spectrum. 



