October. 1910. 



KNOWLEDGE. 



407 



Meteors. — The princip.il meteor shower during the 

 month is that having its radiant point near v Orionis, and 

 hence known as the Orionids. The maximum is from the 

 18th to the 20th, and the meteors are described as swift with 

 streaks. The radiant point is in R.-A. 6" 8"°, Dec. N. 15°. 



Algol presents conveniently observable minima on the 10th 

 at 11.7 p.m., the 13th at 7.56 p.m. and on Nov. 2nd at 9.38 p.m. 

 The period is 2* 20" 49™, from which other minima may be 

 calculated. 



Telescopic Objects: — 



Double St.ars.— y Arietis l" 4S"\ N. 18° 48', magnitudes 

 4'2, 4'4 ; separation, 8"'S. Easy double, power 30 ; notable 

 as being the first double star observed telescopically. 



y Andromedae l" 58"°, N. 41° 54', magnitudes 2'1. 4'g ; 

 separation 10 . The brighter component is intensely yellow. 



whilst the other is greenish blue. The fainter star is remark- 

 able for being a Binary, the components of which are now less 

 than 1 " apart. 



N"ebul.\e. — Nebula in .Andromeda, easily visible to the 

 naked eye. and readily found by referring to the stars 

 p .and 1' -Andromedae. Seen with a three or four inch 

 telescope, it appears to be an extended oval, which is in 

 reality composed of spiral streams of nebulous matter. 



(32 M.) Nebula close to the great Andromeda nebula, and 

 situated about 2° to the South. It is fairly round, and appears 

 somewhat like a star out of focus. 



lis ^) -lies about the same distance North of the great 

 Andromeda nebula that 32 M does South ; it is faint, but 

 large and elliptical. 



THE OCTOBER METEORIC SHOWER. 

 Rv \\\ I-. I)i:XXING. F.R.A.S. 



October, like August and November, has its special meteoric 

 shower, and it is a very interesting one. though not 

 distinguished by any known cometary relations. It returns 

 every year, and furnishes many of the meteors presented in 

 our skies between about October 10th and 25th. The radiant 

 point is on the North- Eastern boundary of Orion, in 

 92° + 15=, and it rises at about 8" 54" on the 21st. 



Observations of this shower are not possible, therefore, 

 before 9 p.m.. and are best conducted in the morning hours, 

 when the radiant has attained a good ele\ation. I have often 

 found meteors surprisingly abund.ant after midnight on 

 about October 15-20. In certain years, and especially in 

 1877. they appeared in such plentiful numbers that 1 could 

 only record a portion of those visible. 



The Orionids are very similar in their visible aspects to the 

 Perseids of .August, but the radiant points of the two streams 

 apparently present a marked difference of feature. While the 

 Perseid radiant exhibits a nightly displacement, the Orionid 

 centre remains stationary at one and the same position. 

 I have investigated this peculiarity to the best of my means, 

 and have always failed to recognise any traces of motion in 

 the Orionid radiant. 



It would be well if other observers gave attention to this 

 circumstance and derived the place of radiation for each night 

 from October 15th to 25th, but this would require that the sky 

 be watched all or nearly all throu.gh the long October nights, as 

 the shower is not very rich except on about October 19th and 

 20th, when the maximum occurs. 



Another curious fact requiring notice is that in recent years 

 the focus of emanation appears to have shifted, or that a new 

 shower has supplanted the old one. During the last ten years 

 or so I have found the principal display directed from about 

 8 degrees east of the position it occupied in former years. In 

 fact recent showers have come from near f Geminorum instead 

 of V Orionis, the radiant being at 100' + 13' instead of at 

 92° + 15°. This came out prominently from my observations 

 and it remains to be seen whether the alteration of radiant is 

 maintained in future years. 



Perhaps there are two active displays at the points above- 

 mentioned, and they may alternately assume predominance. 

 The question is a very interesting one and deserves full 

 attention. The easterly radiant in Gemini was well seen by 

 Miss Herschel and by Mr. T. \V. Backhouse in 1871, and bv 

 myself in 1877 and 1879. 



This year moonlight will be practically absent from the 

 nocturnal sky and afford an excellent opportunity for observers. 



But something else is needed, and that is a clear atmosphere. 

 If this favours us during the third and fourth weeks of 

 October, a \ery successful series of observations may be 

 obtained. .At this particular season the firmament is rich in 

 meteors and the obser\er will find that he must be very 

 expeditious if he desires to register all the meteors presented 

 before him. 



In the English climate it is unfortunate that our autumn 

 nights are often overcast, and the probability is that at the 

 important epoch for the meteors the sky will be at least 

 partially clouded. The only thing for intending observers to 

 do is to make the best use of such opportunities as may be 

 presented. Some of the nights inter\ening between October 

 10th and 25th will certainly be clear, and the skv should then 

 be attentively watched for the swift, streaking meteors from 

 Orion-Gemini. 



What cannot be accomplished in one year can be done bv 

 amalgamating the results of many years. In deducing facts 

 from mj- own observations I have frequently had to collect and 

 compare materials spreading over a series of years. This has 

 often been really essential owing to the serious breaks in 

 individual years occasioned by moonlight and cloudy weather. 



The heights of the October meteors are nearly the same as 

 those of the August meteors, the average values at beginning 

 and ending of the visible flights being from about 80 to 50 

 miles. But only a few members of the October shower seem to 

 have been doubly observed and to ha\e had their real paths 

 calculated. 



For the purpose of securing the desirable materials 

 observers should watch the sky on systematic lines and record 

 all the pretty bright meteors they notice. If the hours of 

 from 10 to 12 p.m. were selected for simultaneous observa- 

 tions between October 15th and 25th on clear nights, it is 

 probable we should get a considerable number of valuable 

 materials. Let the observers in the S.E. of England direct 

 their watch towards the Western sky, while the observers in 

 the S.W. look Eastwards, and those in the Northern Counties 

 give attention to the Southern heavens. In this manner 

 meteors appearing o\er the central part of the country will be 

 seen by two or three of the persons engaged. 



It is to be hoped that some scheme of cooperation such as 

 this will be adopted, as the results promise to be far more 

 valuable than those accruing from independent efforts. Every^ 

 observer fortunate enough to witness the descent of bright 

 meteors should report particulars to those working at this 

 branch. 



