ASTRONOMICAL PROGRESS AND PHENOMENA. 



53 



sage of the earth through the swarm of meteor- 

 oids (so called by Prof. NewtoD), or disinte- 

 grated particles of Biela's comet, left behind in 

 its former path around the sun, is the generally 

 conceded cause of this shower. The earth an- 

 nually passes, on Nov. 27, near the orbit of the 

 comet, and, were themeteoroid particles evenly 

 distributed along its path, as are those of the 

 August 10th shower, there would be an annual 

 Biela shower on that date, but they are so un- 

 equally scattered that a great shower can oc- 

 cur only once in thirteen years. The next in 

 order will probably be on Nov. 27, 1898. 



Three days before the great Biela shower of 

 Nov. 27, 1872, the writer observed (and it was 

 also seen in many other places) a tine meteoric 

 display of short continuance, whose radiant 

 was in Cassiopeia. Some think it was a shower 

 from the other component of Biela. 



The New Star in the Andromeda Nebula. The 

 sudden appearance of this new star, its gradual 

 decrease in brightness, and final extinction, are 

 fresh in the minds of astronomers. It is not 

 known who first or last saw it; but its disap- 

 pearance from even the largest telescopes took 

 place in the early spring of 1886. It afforded, 

 while visible, a fruitful theme for discussion and 

 speculation. It will probably never be known 

 whether it was connected with the nebula in 

 whose center it appeared, or merely in align- 

 ment with it. It is one of the many curious 

 and inexplicable phenomena that occasionally 

 appear in the heavens, the cause of which as- 

 tronomers are powerless to explain. It may 

 be a periodical temporary star, and in all com- 

 ing time its place will be watched for its re- 

 appearance. Though the heavens afford many 

 examples of periodic variable stars, they offer 

 no known precedent of a periodic temporary 

 star. 



New Star in Orion. On the evening of Dec. 

 13, 1885, Mr. Gore, of Ireland, noticed a sixth- 

 magnitude, reddish star, near the star Chi' (= 

 54) Orionis, which was not on the charts of 

 Harding, Lalande, Weiss, Birmingham, or the 

 DurcJimusterung. As he suspected it to be 

 either a new variable or a new star, the dis- 

 covery was immediately tel^raphed to Har- 

 vard, where Prof. Pickering at once made pho- 

 tometric examination of it, and promptly re- 

 plied that it was of the sixth magnitude. By 

 March 1, 1886, it had decreased, according to 

 Pritchard's photometer, to 7'14 magnitude. In 

 April it was rated by several observers at ninth 

 magnitude, and later as low as the twelfth, but 

 now (Dec. 1, 1886) it is as bright as when first 

 discovered, and is specially remarkable as, in- 

 stead of decreasing to a minimum and there 

 remaining (as did the new star in the Northern 

 Crown, or disappearing entirely, like the new 

 one in Andromeda), it has done neither. Ob- 

 servations continued to near the end of 1886 

 have convinced astronomers that the star is an 

 ordinary variable, with a period not far from 

 a year. Its light appears to fluctuate from 

 about the fifth magnitude at its maximum to 



the twelfth at minimum. It is therefore not a 

 temporary star, as at first supposed, because of 

 its absence trom all star-charts. Its spectrum 

 is peculiar; and though astronomers are not 

 agreed as to its precise nature, yet all admit 

 that it belongs to Secchi's third type, of which 

 a Orionis, a Hercules, o Ceti, and ft Pega.si are 

 the brightest examples. Its position for Janu- 

 ary, 1885, was, by meridional observation, R. 

 A. 5 h - 47 m - 13% Dec. + 20 8' 42". It seems to 

 be a clean-cut star, without haziness, disk, or 

 apparent motion. 



Proper Motion of Stars. The proper motion of 

 the stars, whether in the line of sight or at 

 right-angles to it, is to the astronomer a fasci- 

 nating subject. Before the distance of any of 

 the stars had been measured, it was the re- 

 ceived opinion that the brighter stars were the 

 nearer to our system, and, had they any appar- 

 ent motion, that it would be largest in these ; 

 but both assumptions are erroneous, for, as far 

 as is now known, not a single bright star has a 

 proper motion at right-angles to the line of 

 sight, equal to that of some of the fainter ones. 

 The following list includes a few of the stars 

 whose proper motions are best known. No. 1 

 has long stood at the head as having the 

 largest proper motion of any known star. The 

 actual velocity in miles depends, of course, 

 upon its distance from us : 



It will be readily seen that there is but little 

 correspondence between motion and parallax. 

 The absolute motion of No. 1, whose apparent 

 motion is so great with a parallax so small, is 

 altogether incomprehensible. About 5'5 S - south 

 preceding of 70 Ophiuchi is a star of about the 

 thirteenth magnitude, which has the largest 



g roper motion of any star of that degree of 

 dntness known. Its parallax (and of course 

 its distance) is unknown. 



Satellite Orbits. In Appendix I to vol. xxviii of 

 the " Washington Observations," Prof. Asaph 

 Hall discusses the observations of Oberon and 

 Titania, the two outer satellites of Uranus, 

 made by himself, with the 26-inch refractor 

 of the Naval Observatory, during the years 

 1875-76 and 1881-'84. From these he makes 

 the mass of Uranus = ^^-|-g-^, that of the sun 

 being equal to 1. Appendix II, of the same 

 volume, contains a similar discussion of his ob- 

 servations of the satellite of Neptune. He 

 finds the mass of that planet to be Tyfo-y ; or ? 

 in other words, it would take 19,092 Neptunes 

 to equal the sun's mass. He deduces the value 

 of the mass of Saturn to be 34 | 13 . 



