114 



NA TURE 



[Dec. I, 1887 



OUR ASTRONOMICAL COLUMN. 



Probable New Variables. — Mr. John Tebbutt calls atten- 

 tion in the Obsei-v.itory for November to the double star 02 256, 

 one of the components of which appears to be variable ; for 

 during the occultation of the star on August 22 the preceding 

 -component appeared very distinctly the brighter of the two, 

 whilst Crossley and Gledhill, in their " Hand-book of Double 

 Stars," regard this star as the companion. Struve was ap- 

 parently the first to draw attention to the probable variability of 

 this star, for whilst he usually estimated the preceding star as 

 the brighter by half a magnitude, Dembovvski recorded it as 

 being the fainter by that amount. 



Dr. Bauschinger (.^j/r. Nacli. No. 2810), finds that a star in 

 Libra, Lanij 1875, Munich Zones 695 — place for 1855 'o, R.A. 

 I5h. 4m. i"5s., Decl. 5° 27' '6 S. — is also probably variable. 

 Lamont gives the star as of the eighth magnitude ; Dr. Bau- 

 -schinger finds it 9*2 m.; it is wanting in the southern Durch- 

 musterung. Dr. Schonfeld writes that he observed the star on 

 two, if not three occasions ; once as 10 m. and once as 12 m. It 

 should therefore be added in the Bonn. Beob. vol. viii., after 

 - 5° No. 4028, as : — 



" Var. i5h. 4m. 2-5S., 5° 27'-5 M." 



Names of Minor Planets. — Minor Planet No. 268 has 

 received the name of Adorea ; No. 270 that of Anahita. 



The Spectra of Oxygen and Carbon compared with 

 that of the Sun. — Prof. Trowbridge and Hutchins have pre- 

 sented to the American Academy of Arts and Sciences a paper 

 on the spectra of oxygen and carbon as compared with that of 

 the sun. In the case of the former element, Dr. Henry Draper 

 had convinced himself that there were bright lines in the solar spec- 

 trum corresponding to the bright lines of oxygen, whilst his brother. 

 Prof J. C. Draper, had identified the oxygen with faint dark 

 lines, but the present experimenters conclude that " so far as con- 

 cerns the spark spectrum in air and the solar spectrum from 

 wave-lengths 3749 '8 to 5033 '85 they can safely affirm that there 

 is no physical connection between them." They "have photo- 

 graphed the sun's spectrum every day that the sun has shone for 

 nearly five months, without finding a line that could with certainty 

 be pronounced brighter than its neighbours " ; the powerful dis- 

 persion given by the large concave Rowland grating employed 

 by Messrs. Trowbridge and Hutchins causing the "bright bands 

 to vanish," which Dr. H. Draper thought he had discovered, and 

 which seemed conspicuous with the dispersion he used, whilst it 

 showed at the same time that there was no real correspondence 

 between the oxygen lines and the dark lines Prof J. C. Draper 

 had identified with them. Lack of sufficient instrumental power 

 had led both of the two earlier observers astray. 



With regard to carbon, Messrs. Trowbridge and Hutchins are 

 of opinion " that the fluted spectrum of carbon is an example of 

 the reversal of the lines of a vapour in its own vapour," and 

 they find a striking coincidence in many cases between the spaces 

 separating the fine bright lines of the flutings and dark lines in 

 the solar spectrum, twenty-eight such coincidences being traced 

 within the limit of ten wave-lengths in the fluting at wave- 

 length 38837. Their hypothesis as to the origin of the flutings 

 leads them "to conclude that, at the point of the sun's atmosphere 

 where the carbon is volatilized so as to produce the peculiar 

 arrangement of reversals observed, the temperature of the sun 

 approximates to that of the voltaic arc." 



Olbers' Comet, 1887.— The following ephemeris for Berlin 

 midnight for this object is in continuation of that given in 

 Nature, vol. xxxvi. p. 588, and vol. xxxvii. p. 37, and is by 

 Herr Tetens {Astr. Nach., No. 2813) : — 



Dec, 



. I .. 

 3 ••• 

 5 - 

 7 -. 

 9 ... 



II .. 



13 .., 



IS .. 



17 ... 



R.A. 



h. m. s. 

 15 26 36 



15 32 7 

 15 37 31 

 15 42 49 

 15 48 o 

 15 53 4 



15 58 2 



16 2 54 



Decl. 



109 N. 

 347 

 59-5 

 25-1 



Si-6 

 191 



47-5 

 i6'9 



Log r. 

 0-1594 

 01692 

 0-1790 



o'iSgo 



Log A. 



0-3354 

 0-3417 

 0-3478 

 0-3537 



16 7 41 ... 2 47'2 N. ... 0-1990 ... 0-3593 



Bright- 

 ness. 

 .. 0-84 



... 0-78 



•• 0-73 

 ... 0-68 

 ... 0-63 



The brightness on August 27 is taken as unity. 



A Vienna observation of October 21 gives the error of the 

 ephemeris as R.A. + 3s. and Decl. + o'-2, and this will 

 probably slowly increase. 



ASTRONOMICAL PHENOMENA FOR THE 

 WEEK 1887 DECEMBER 4-10. 



/-pOR the reckoning of time the civil day, commencing at 

 ^ Greenwich mean midnight, counting the hours on to 24, 



is here employed.) 



At Greenwich on December 4 



Sun rises, 7h. som. ; souths, iih. 50m. i9-6s. ; sets, ish. ^\va. : 



right asc. on meridian, i6h. 42-2m. ; decl. 22° is' S. 



Sidereal Time at Sunset, 2oh. 44m. 

 Moon (at Last Quarter on December 8, 3h.) rises, i8h. 39m.*; 



souths, 2h. 44m. ; sets, loh. 44m. : right asc. on meridian, 



7h. 34 "om. ; decl. 20° o' N. 



Right asc. and declination 

 Planet. Rises. Souths. Sets. on meridian. 



h. m. h. m. h. m. h. m. » / 

 Mercury.. 5 46 ... 10 27 ... 15 8 ... 15 18-9 ... 15 49 S. 

 Venus ... 3 20 ... 8 45 ... 14 10 ... 13 36-7 ... 7 36 S. 

 Mars ... o 53 ... 7 8 ... 13 23 ... 11 58-9 ... 2 8 N. 

 Jupiter ... S 5^ ... 10 27 ... 14 58 ... 15 18-9 ... 17 25 S. 

 .Saturn ... 19 57*... 3 45 ... il 33 ... 8 35-1 ... 19 6 N. 

 Uranus... 2 3S ... 8 9 ... 13 43 ... 13 o-6 ... 5 46 S. 

 Neptune-. 15 11 ... 22 52 ... 6 33*... 3 45-8 ... 18 5 N. 



* Indicatesthat the rising is that of the preceding evening and the setting 

 that of the following morning. 



Occultation of Star by the Moon (visible at Greenwich). 



Corresponding 



Dec. 



6 .. 



Dec. 



4 



Star. 



7 Leonis 



h. 

 ,.. II .. 



Mag. Disap. 



6i 



5 iJ 



Reap. 



6 27 



angles from ver- 

 tex to right for 

 inverted image. 



... 59 300 



35 



Mercury in conjunction with and 



north of Jupiter. 

 Saturn in conjunction with and 0° 51' north 



of the Moon. 

 Mercury at greatest elongation from the Sun, 



21° west. 

 Mars in conjunction with and 2° 10' south 



of the Moon. 



Saturn, December 4. — Outer major axis of outer ring = 44"'3 ; 

 outer minor axis of outer ring = I4"*2 ; southern surface visible. 



5 



Variable Stars. 



Star. 



U Cephei 



R Sculptoris 

 Algol 



\ Tauri 



S Orionis 



C Geminorum 



R Canis Majoris.. 



T Cancri 



5 Virginis 



U CoronEE 



6 Lyrse 



S Vulpeculse 



Y Cygni 



R.A. 



52-3 •• 



21-8 .. 



0-8 .. 



54-4 •• 

 23*4 •• 

 57'4.. 

 14-3 •• 



Decl. 



si 16 N. 

 33 8S. 



40 31 N. 



12 10 N. 



4 47 S. 



20 44 N. 



16 II S. 



Dec. 



8 So-2 

 13 27-1 

 IS 13*6 



18 45*9 



19 43*8 



20 46-8 



20 17 N. 

 6 37 S. 



32 4N. 



33 14 N. 



27 o N. 



34 10 N. 



10, 



6, 

 9. 



7, 23 

 5. 4 

 1, 



h. m. 

 o 46 m 



M 



2 46 m 



23 35 m 



2 17 w 



M 



19 o »/ 



20 56 m 

 o 12 m 



M 



M 



4 m 



M 



R Vulpeculae ... 20 59*4 ... 23 22 N. ... ,, 



5 Cygni 22 25-0 ... 57 50 N. ... ,, 



M signifies maximum ; in minimum. 



Meteor- Showers. 

 R.A. Decl. 



5, 22 23 m 

 8, 22 17 m 



5, ;// 



6, 23 o M 



Near 7 Persei 44 ... S^ N. 



The Taurids II. ... 80 ... 23 N. 



The Geminids ... 107 ... 33 N. 



Near 5 Geminorum ... no ... 24 N. 



Near w Leonis 14S ... 8 N. 



Near y3 Ursa; Majoris. 162 ... 58 N. 



Very slow ; faint. 

 Slow ; brigjit. 

 Swift ; short. 

 Rather swift. 

 Swift ; streaks. 

 Very swift ; streaks. 



