ASTRONOMICAL PHENOMENA ANI> PKi M, I :!>>. 



67 



ih, tliv. r^'ing from the Milky-Way at the 

 and litta t'n/ar, comprises ti. 



md ex- 

 ru through 6JpAwoe* toward Zyro. Tims 



..neol I'riirht stars srems to gird 

 HILT with the Milky-Way at the 

 - .1 manifest at all seasons, although 

 i-piciioiis upon tin- i irioii M'lr than on tho 

 1 poii my return to tho North, I sought im- 

 for tin: northern place of intersection; 

 11 hough tin- phenomenon is by far less clearly 

 tilih- in this ht-misphere, 1 found no difficulty 

 !; tin- nodi) m the constellation Cawio- 

 .: metrically opposite to Crux. In- 

 t is easy to fix the right ascension of the north- 

 >de at about 0*- SO-, and that of the southern 

 12 k - 60 m - ; the declination being in each case 

 |JO, so that these nodes are very close to the 

 - at which the Milky-Way approaches most 

 nearly t> the poles. The inclination of this stream 

 Milky-Way is about 25, the Pleiades occupy- 

 ing a position midway between the nodes. 



Dr. Gould, after noticing this remarkable cir- 

 cle and commencing the preparation of data in 



it-ill form to demonstrate its existence, 

 found that he had been partially anticipated by 

 >ir .lolm Herschel. The British astronomer, 

 however, " does not appear to have recognized 



it-t that this zone of bright stars may be 



i with tolerable distinctness through the 



.iniru circuit of the heavens, forming a great 



as well defined as that of the Galaxy it- 



These interesting researches, a detailed 



.tit of which is given in the paper referred 

 to, may have an important bearing on the great 

 problems of determining the position of our sun 

 in the cluster to which it belongs, the form of 

 the cluster itself, and the relative distances be- 



:i the stars of which it is composed. 

 The Companion of Procyon. It is well 

 known that the star Procyon has manifested 



lerable irregularity in its motion, and 

 that the celebrated Bessel ascribed the phe- 



uon to the disturbing influence of an un- 

 discovered companion. In 1851 Prof. O. Struve 

 commenced a series of observations on this 

 star with the view of obtaining, if possible, ma- 



- for the confirmation of Bessel's theory, 

 researches were without any positive re- 

 sult till the 19th of March, 1873, when, under 

 exceptionally favorable atmospheric conditions, 

 a faint point of light was detected at a distance 

 of about twelve seconds from Procyon. Prof. 

 Stnue immediately concluded that the newly- 

 di-rovered star was a satellite, whose orbital 

 motion had but recently brought it so far out 

 of the rays of the bright star as to render it 

 separately visible. Unfortunately, however, 

 before any definite conclusion could be reached, 

 the apparent -relative positions of the sun and 

 Procyon had so far changed as to render fur- 

 ther observations of the small star impossible. 

 The beginning of the year 1874 was singu- 

 larly unfavorable for telescopic researches, and 

 it was not till the 21st of March that Struve 

 succeeded in rediscovering the point of lijjht 

 which he had detected in March of the previous 

 year. In April he obtained a number of satis- 

 factory observations ; the distance of the com- 



paiiit.n, as well as the jMjMlion-angle, being 

 can-fully measured. '1 lie intcroliiig results are 

 thus stated by Struve himself : 



It is well known that Prof. Auwcrs, as soon at he 

 hud received my observations of last year, repeated 

 his investigations into the variable proper niti<>n of 

 /(, availing himself of the observations of this 

 star which have been made since 1862. From this 

 he concluded that it was doubtful whether the ob- 

 ject observed by me was really the sole body dis- 

 tui-liing the proper motion of JVocyow, but that the 

 doubt would be removed if it appeared this spring 

 that the position-angle had undergone an increase ot 

 from 9 to 10*. And this increase has really shown 

 itself in the most remarkable manner. I consider it, 

 therefore, to be decisively established .that the ob- 

 ject 1 have observed is actually the companion whose 

 existence has been theoretically proved by the cal- 

 culations of Auwers ; and hope that the astronomi- 

 cal world will rejoice with me in the triumph thus 

 obtained for the labors of my honored friend, and 

 through them for our common science. In order to 

 remove any exception that might be taken, that the 

 wished-for result had in any degree been itself the 

 cause of the recognition, and affected the measure- 

 ment of the place of so difficult an object. I will jut 

 remark that I had not looked again at the paper of 

 Auwers in question since its first receipt last sum- 

 mer, and had totally forgotten the data of its crite- 

 rion, and the mutual relation of the two stars. I did 

 not again take it up until after I had succeeded in 

 making the first observation, and the results of that 

 paper were even less present to the mind of my as- 

 sistant, Herr Lindemann, whose younger eye ap- 

 pears generally to have seen the companion even 

 better than mine. 



According to Prof. Auwers, Procyon com- 

 pletes a revolution in forty years. Its orbit is 

 nearly circular, and its plane perpendicular to 

 the line of sight. Taking its parallax at one- 

 fourth of a second, he finds the mass of the 

 principal star to be eighty times that of the 

 sun, or more than eleven times that of Struve's 

 satellite. 



The Nebula near Eta Argils, The results 

 of further observations on the star Eta Argut 

 and its adjacent nebula were reported by Mr. 

 E. J. Ellery, of the Melbourne Observatory, nn- 

 der date of January 28, 1874. Marked changes 

 had been noticed during the six months pre- 

 ceding that date. The great bay of the lem- 

 niscate had nearly filled up with dense nebula, 

 leaving a dark sigmoid inlet. Nebula appar- 

 ently less dense had also formed from side to 

 side 'of the opening in which Eta is situated 

 threatening to completely involve the star. 

 These rapid variations, where it was supposed 

 until recently that cycles of immense duration 

 would be required for any sensible change, 

 are regarded by astronomers with no ordinary 

 interest. 



Mr. Burnham's Catalogue of New Double 

 Stars. S. W. Burnham, Esq., of Chicago, has 

 communicated to the Royal Astronomical So- 

 ciety of London five catalogues of new double 

 stars, amounting in all to 300. A number of 

 these are naked-eye stars which have been fre- 

 quently examined by other observers. In some 

 cases the components of binary stars have them- 

 selves been found double. Alpha Delphini^ 

 which had been, known as a triple star, is 



