176 



KNOWLEDGE. 



[August 1, 1899. 



of place to attempt to solve the problem in any other way. 

 Attention may, however, be directed to the circumstance 

 that the C'hiru, or Tibetan antelope, has a remarkably 

 swollen and puffy nose. And although the Saiga antelope, 

 of the plains of Central Russia, has an equally remarkable 

 nasal development, yet it seems highly probable that in the 

 case of the Chiru, at any rate, the enlarged size of the 

 nasal chamber and nostrils is correlated with the rarefied 

 atmosphere of the elevated plateau on which that ruminant 

 dwells. The Snub-nosed Monkeys, although living at a 

 considerably lower elevation than the Chiru, are yet " well 

 up in the world ";• and since the shape of the nose in the 

 former would appear designed to admit the passage of as 

 much air as possible with the least impossible impediment, 

 the suggestion that the habitat has something to do with 

 the nose-structure may perhaps be suggested. As to the 

 reason for the genesis of the imgainly proboscis of the 

 Bomean monkey, we have not even the rudiment of a 

 theory to offer our readers. 



SOME SUSPECTED VARIABLE STARS. 

 By J. E. Gore, f.r.a.s. 



THERE are many stars which have been suspected 

 of being variable in their Ught, but which have 

 not yet been admitted into the ranks of " known 

 variable stars." The following are some of the 

 most remarkable and interesting cases. 

 The brilliant star Capella (a Auriga) was suspected of 

 variability by Struve, who, in a letter to Sir John Herschel 

 in 1838, stated that he considered Capella was increasing 

 in brightness, and Sir John Herschel agrees with him.* 

 From observations made in 1855 by Mr. Benedict EUner, 

 of Bamberg, Bavaria, he found that Capella varied in 

 brightness (1-0 to 1-9), and also in colour — from whitish- 

 yellow to red. In the Monthly Notices of the Royal Astro- 

 nomical Society for November, 1859, observations on the 

 brightness of Capella are given by J. B. Kearney, of King's 

 School, Canterbury. From February to April, 1858, he 

 found Capella equal to Vega. Between November, 1858, 

 and August 1859, Capella seemed rather brighter than 

 Vega, but on August 19, 1859, " Capella was brighter 

 beyond all possibility of doubt than either Arcturus or 

 a Lyra;. At 10 o'clock Capella was magnificent, very far 

 surpassing all its rivals. It flashed all manner of colours, 

 blue and crimson being perhaps the most striking." On 

 September 9th, 1859, he considered Capella sUyhtly first, 

 Arcturus a good second, and Vega, though very bright, 

 third. My own observations, 1883 to 1886, make Capella 

 sometimes brighter than Arcturus, and sometimes dis- 

 tinctly fainter. Capella was measured 0'08 at Oxford and 

 0'18 at Harvard, or nearly one magnitude brighter than 

 an average star of the first magnitude. 



Sir John Herschel found Arcturus brighter than Capella 

 on April 14th, 1838. f It was measured 0-31 magnitude 

 at Oxford (1882-1883), and 0-03 at Harvard. My own 

 observations, as already stated, make Arcturus sometimes 

 brighter and sometimes fainter than Capella, but the 

 brilliancy of the stars and their distance apart render 

 observations difficult and uncertain. 



Canopus (a Argus). — This fine star — second only to 

 Sirius in brilliancy — does not rise above the English 

 horizon. In the Chinese Annals it is called Laou Jin, 

 "the Old Man." Webb says, "It was thought, 1861, 

 in Chili brighter than Sirius." Although it attained a 

 meridian altitude of only seven degrees at my station in 



• " Cape ObservationB," p. 350. 



t /frirf., p. 325. 



the Punjab, I observed it in 1874 to be very little inferior 

 to Sirius. It was measured with the meridian photometer 

 by Prof. Bailey at Arequipa, Peru, and found to be —0-96 

 magnitude, or about one magnitude brighter than the 

 zero magnitude, that is about one magnitude brighter than 

 Capella. As Sirius was measured —1-43 with the same 

 instrument at Harvard, the result found by Prof. Bailey 

 would make Canopus only about half a magnitude less 

 than Sirius. It is certainly a splendid star, and may 

 perhaps be variable to some extent, but owing to its great 

 brilliancy suitable comparison stars are not available. 



The star /? Leonis, or Denebola, is almost certainly 

 variable in light, but the period may be one of many years. 

 It was rated 1st magnitude by Ptolemy, Al-Sufi, and 

 Tycho Brahe, 1^ by Flamsteed, 1^ by Hevelius, but only 

 2nd magnitude by Lalande, Argelander, Heis, and others. 

 In Schjellerup's translation of Al- Sufi's "Description of the 

 Heavens " (tenth century) the star is thus described, " La 

 27 (/3) de la premiere grandeur est la brillante et grande 

 qui se trouve sur la queue ; elle suit la brillante vingtieme 

 etoile 8itu6e dans la reins. C'est celle que Ton marque sur 

 I'astrolabe et que Ton nomme dzana al thad, la Queue du 

 Lion." Al-Sufi uses exactly similar words in describing 

 Kegulus (a Leonis), and, considering the great accuracy 

 of all Al-Sufi's descriptions, it seems certain that in those 

 days Denebola was fairly comparable in brightness with 

 Regulus. The Arabians also called Denebola al-sarfa, 

 " the vicissitude," possibly with reference to fluctuations 

 in its light. Sir William Herschel, who made careful 

 observations of the relative brilliancy of all the brighter 

 stars in the Northern Hemisphere towards the close of the 

 eighteenth century, rated Denebola as slightly less than 

 y Leonis, but slightly brighter than i, or, in his notation 

 41 (y), 94 (/3) (denoting that y was " the least perceptible 

 diflerence " brighter than ^). He says,* " this expression 

 can certainly not be changed to 94, 41 ; much less can the 

 order of three such stars as 20, 40, 39 Libras admit of a 

 different arrangement. If ever the state of the heavens 

 should be such as to require a different order in these 

 numbers, we need not hesitate a moment to declare a 

 change in the brightness of one or more of the stars that 

 are contained in the series to have taken place." Herschel's 

 estimate of the relative brightness of /3 and y Leonis is 

 now certainly changed, as will be seen presently. Herschel 

 says, further, with reference to /3 Leonis, " From the 

 expressions of this catalogue, it is evident that the star is 

 less now than it was thirteen years ago. The magnitude 

 of this star given by Flamsteed is 1-2, but, as there is some 

 ground to admit that this magnitude, even in this coarse 

 way of reference, may be distinguished from what the same 

 author seems to have taken for 2 mag., we conclude that 

 this star has probably lost some of its former brightness." 

 Again, he gives Beta 1-2 mag., and Gamma 2 mag. This 

 notation seems to imply that Beta is larger than Gamma, 

 which, not being the case, we have additional reason to 

 suspect a change. De la Caille puts down Beta as 2 mag., 

 though the difference between the notation of Flamsteed 

 and the latter author can add little force to the argument 

 for a change, as we have observed before, that a consider- 

 able allowance must be made for nominal variations in 

 different authors. Nor can we draw any support from the 

 magnitude itself, because the star will pass very well for 

 one of that order when compared with other stars which 

 are marked 2 mag. by the same author ; but when De la 

 Caille marks Beta 2 mag. and Gamma 3 mag., we may 

 conclude that he estimated Beta to be larger than Gamma, 

 though we do not know that he compared these stars 



• Philosophical Translatiotu of the Royal Society, 1796. 



