38 



ASTRONOMY, PROGRESS OF, IN 1892. 



Comet c (Pons-Winnecke) was detected on 

 March 18, 1892, by Spitaler. It has been un- 

 usually bright at this apparition, but, unfortu- 

 nately, when brightest it was badly situated, 

 setting soon after the sun and observable only 

 in strong twilight. 



Comet d (Brooks) was found by W. R. Brooks, 

 Director of the Smith Observatory, at Geneva, 

 N. Y., on Aug. 28. Its elements have been com- 

 puted by Dr. Berberich as follows : 



Perihelion passage, 1892. Dec. 19-69 : 



Node to perihelion - 269 24' 

 Longitude of node =261" 8' 

 Inclination = 27 57' 



Perihelion distance = 6991 



This comet promises to be much brighter be- 

 fore arriving at perihelion. 



Comet e (Barnard). On the evening of .Oct. 

 12, Prof. E. E. Barnard, of the Lick Observa- 

 tory staff, while engaged in a systematic, photo- 

 graphic study of the Milky Way, secured several 

 plates. The next day, in developing the nega- 

 tives, he was surprised to find depicted on one 

 of them the impress or trail of a comet, which 

 was visually observed that evening, Oct. 13, in 

 right ascension 19 h 34 m ; declination north 12 

 80'. Its daily motion is 1 40' southeasterly. 

 This is the first instance of a photographically 

 discovered comet. 



From observations of Oct. 15, 16, and 17, Prof. 

 Campbell, of the Lick Observatory, has com- 

 puted the following elements: 



Perihelion passage, 1892, Aug. 26-14, Greenwich mean 

 time : 



Node to perihelion = 114 2' 

 Longitude of node = 184 13' 

 Inclination = 48 V 



Perihelion distance = 1-9904 



Neither Tempel's comet (1867, II), nor Brooks's 

 (1886, IV), both periodic, and for which finding 

 ephemerides were published, have been ob- 

 served. 



Spectrum of Surift's Comet. Prof. W. W. 

 Campbell, of the Lick Observatory, who on 

 April 6 made spectroscopic observation of this 

 comet with the 36-inch equatorial, says in 

 " Astronomical Journal " of April 16 : " The spec- 

 trum is of the usual type. That of the nucleus is 

 apparently continuous and visible from about 

 C to G. The three well-known yellow, green, 

 and blue bands were present, their intensities 

 being, approximately, in the ratio 1:6:2. Their 

 lower edges were quite sharply defined. When 

 the slit was narrowed to 0*004 inches the bright 

 line on the lower edge of the green band became 

 exceedingly sharp, and could be bisected with 

 the micrometer thread with extreme accuracy. 

 A 60 prism was used." He gives the wave 

 lengths of the three bands as 5,630, 5,170-4, and 

 4,723 respectively. 



Dr. Konkoly, of O'G valla, also observed the 

 spectrum and found five bright lines. 



Long Visibility of a Comet. Until recently 

 the great comet of 1811 had the longest period 

 of visibility of any known, previous or subse- 

 quent viz., eighteen months but Barnard's 

 comet (1889, I), discovered on Sept. 2, 1888, was 

 still to be seen by the mammoth telescope of the 

 Lick Observatory, with its great light-gathering 

 power, on Aug. 18, 1890, seven hundred and fif- 

 teen days after its finding, and when its distance 

 from the sun was 6-25 times that of the earth, 



or about 580,000,000 miles, exceeding that of 

 some of the short-period comets at their aphelia. 



A Fifth Satellite to Jupiter. The an- 

 nouncement recently telegraphed from the Lick 

 Observatory of the finding of a new and fifth 

 moon to the giant planet, which was at first re- 

 ceived with incredulity, has been confirmed. 

 Prof. E. E. Barnard has given in " Astronomical 

 Journal " of Oct. 4, 1892, a complete account of 

 the discovery supplemented with micrometrical 

 measurements. Having the use of the great 

 telescope on one night in each week, he says: 

 "Nothing of special importance was encoun- 

 tered until the night of Sept. 9, when, in care- 

 fully examining the immediate region of the 

 planet Jupiter, I detected an exceedingly small 

 star close to the planet and near the third 

 satellite. I at once measured the position angle 

 of the object with reference to Satellite III." 

 This being the only measurement made on that 

 evening, he did not think the proof sufficient to 

 warrant the publication of the discovery, which 

 was not done until Sept. 10. As to the diameter 

 of the satellite he declares it quite impossible to 

 tell, but estimates it as being of the thirteenth 

 magnitude, which would imply that it ought to 

 be seen with a 16-inch telescope, and yet he as- 

 serts that it would require one of 26 inches 

 aperture to observe it. As he considers it a 

 more difficult object than the satellites of Mars, 

 its previous nondiscoveryis not at all surprising. 



From a mean of three observations for dis- 

 tance made on Sept. 10, 12, and 14, he deduces 

 its distance from the center of Jupiter to be 

 about 112,450 miles or 70,000 miles from his sur- 

 face. The mean period determined from the 

 above observations is ll h 49'63 m , its hourly or- 

 bital velocity being about 60,000 miles. Prof 

 Young has also observed it, and makes the period 

 of revolution a little greater. The discovery of 

 this satellite is one of the most wonpcerful astro- 

 nomical events of the nineteenth entury. 



New Star in Auriga, On Feb. 1, 1892, Dr. 

 Ralph Copeland, Astronomer Royal of Scot- 

 land, received an anonymous postal card with 

 the following legend: "Nova in Auriga: in 

 Milky Way about 2 south of Chi Auriga, pre- 

 ceding 26 Auriga ; fifth magnitude ; slightly 

 brighter than Chi." This star was easily found 

 with an opera glass by Dr. Copeland and ex- 

 amined by him with a prism, and found to pre- 

 sent a spectrum very like the new star of 1866. 

 When cabled to this country, Prof. Pickering 

 examined his photographic plates of that region, 

 and found depicted on one of them a star with 

 a unique spectrum, whereupon he sent the 

 following cablegram to Dr. Copeland : " Nova 

 bright in photograph Dec. 10th, faint on Dec. 

 1st, maximum Dec. 20th." This, it appears, is 

 the extent of our knowledge of its first appear- 

 ance, an astronomical phenomenon that has at- 

 tracted great and world-wide attention. Subse- 

 quently a letter was received by Dr. Copeland 

 from Rev. Thomas D. Anderson, the writer of 

 the anonymous card, who therein declared him- 

 self its author. The telescope used by the rev- 

 erend amateur astronomer is a small spyglass 

 of l-inch aperture, magnifying ten times. It 

 shows in a striking manner how sometimes an 

 important discovery may be achieved with small 

 means if combined with energy arid enthusiasm. 



