130 



KNOWLEDGE. 



[June, 1901. 



on the part of Piazzi, the Sicilian astronomer. In his 

 catalogue he introduced for these two stars the names 



'Si »i' AURIGA 



URSA 



CVGNUS 



w lYSA t- . 



VULPECyiA . . ae ^oi^' 



DftPHINUS 



SflCiTTA 



V CAPmCORNUS 



ftQUILLA « 



^Serpens f 



9 ' 

 SERPENS 

 OPHIUCHUS f * 



SACITTAItlUS- ■''Sg&.i.-^. 



3.- w 



*' 



LIBRA 



The Midniglit Sky for London, 1901, June 2. 



Rotanev and Svalociu, names which gave a good bit 

 of trouble to etymologists until it was seen that they 

 were simply the name of Piazzi 's assistant Niccolo 

 Cacciatore, latinized and spelt backwards. 



NEW STARS. 



By the Rev. A. L. Coetie, s.j., f.e.a.s. 



The appearance of the brilliant star in the coniteilation 

 Perseus, discovered by the Reverend Dr. Anderson, of 

 Edinbin-gh, in the early morning of Februai-y 22nd. has 

 naturally awakened the keen interest of astronomers in 

 the subject of the origin and composition of such bodies. 

 In the twenty centuries that elapsed between the years 

 B.C. 134 and a.v. 1892, when the last new star visible 

 to the naked eye, previous to the advent of the present 

 stranger, was also discovered by Dr. Anderson, only nine- 

 teen cases of such appear-inces have been recorded. 

 Another six, of small magnitude and invisible to the 

 unaided eye, appeared on the photographic plates secured 

 in the period 1877 to 1899 by the indefatigable director 

 of the Harvai'd College Observatory, Professor E. C. 

 Pickering. Of the first new star known to us by historical 

 records, we learn the bare fact that its discovei-y 

 was due to Hipparchus, and the interesting statement 

 of Pliny that it suggested to the Greek astronomer the 

 construction of a catalogue of stars, the earliest that is 

 extant. Of the other new stars discovered before the 

 general adoption of the spectroscope and photographic 

 plate as powerful auxiliaries of the telescope, the most 

 famous was Tvcho Brahe's star, which blazed out in the 

 constellation Cassiopeia in the year 1572, and was visible 

 for a year and five months, rtvalling at first Venus and 

 then Jupiter in brilliancy. Of this star it is recorded 

 that its colour changed from white through yellow to red, 

 and then to white again, thus furnishing some indication 

 of a probable fluctuation in and recuperation of its light, 

 phenomena which have been also marked in succeeding 

 new stars. Another Venus-like star was tliat observed 

 bv t.Iie famous Kepler in a.d. 1604, and visible for a year. 



The brilliancy of this star joined to a conjunction of the 

 planets Jupiter, Mars, and Saturn in the same part of 

 the heavens led the illustrious astronomer to propound 

 the theory that it was a similar phenomenon which 

 appeared to the wise men in the East and led them to 

 Bethlehem. The same century witnessed yet another 

 outburst, in the year 1670, this time near the star/3 C3 gni, 

 the detection of the star being due to the Carthusian 

 monk Anthelmus. This star was visible for two years, 

 and likewise exhibited fluctuations in its light. The 

 century just completed was marked by five such 

 apparitions, namely : in 1848, w-hen a star was discovered 

 by Dr. Hind in the constellation Ophiuchus ; in 1866, 

 when a star in the Northern Crown blazed up suddenly 

 from the ninth to the fourth magnitude, and after again 

 increasing its lustre six-fold in about six hours, finally 

 became a variable; in 1876, when a star of an orange-red 

 tint appeared in the constellation Cygnus, which attained 

 a lustre equal to that of a third magnitude star, and' 

 which when observed by Buniham at the Lick Obsei-va- 

 tory in 1891 was a small star of 13. .5 magnitude, and " at 

 times seemed to resemble an exceedingly minute 

 nebula"; in 1885, when a star appeared in the very 

 heart of the Andromeda Nebula; and finally in 1892, 

 \\hen Nova Aurigae was discovered. On the appearances 

 pi'esented by this star it will be necessarj- to dwell some- 

 what in detail, as it marked a considerable advance in 

 our knowledge of the varying ijhenomena of such tem- 

 porary visitants. It was certainly not of the eleventh 

 magnitude on December 8th, 1891, otherwise it would 

 have impressed its image on the photographic plates of 

 that portion of the sky taken by Dr. Max Wolf of Heidel- 

 berg. Two days later it was on the plates taken at 

 ITaivard College, and was of the fifth magnitude. It 

 attained its first maximum of 4.4 magnitude on Decem- 

 ber 20th. It then decreased slowly in brightness with 

 slight fluctuations until January 20th, 1892, when it was 

 somewhat below the fifth magnitude. It was first seen, 

 and discovered by Dr. Anderson, for its prior history 

 by means of the photographs was only elucidated subse- 

 quently to his announcement, as a fifth magnitude star 

 on January 24. After this it received another access of 

 lustre and attained a second maximum of between the 

 third and fourth magnitude on February 3rd. It then 

 staadily grew fainter, with the exception of another 

 slight rise in magnitude between March 16-19, 

 until at the beginning of April it was equal 

 to a faint thirteenth magnitude star. On April 

 24th the Lick observers estimated its magnitude 

 as sixteen. But in August of the same year, it 

 again recuperated its energies, rising to the ninth mag- 

 nitude, or increasing in brightness nine hundred fold. 



There occurred, therefore, in this star a sudden out- 

 burst, a rapid rise to brilliancy, a fall, another rise to 

 maximum brightness, again a fall, a third rise, tliough 

 less brilliant tlian its predecessors, and then a rapid and 

 persistent fall to extreme faintness. But four months 

 after, it became an easily discernible telescopic object, its 

 haziness of outline suggesting that it too had become a 

 nebula. 



With regard to the nova of the present year, although 

 the observations have not yet been completed, we notice 

 a similar sudden burst from a low to a high magnitude, at 

 least 12i magnitudes in three days, corresponding to a 

 100,000 "fold Increase in its light, a similar gradual de- 

 cline with fluctuations of brilli-ancy, so that at the end of 

 March the star seemed to have become a variable with 

 a period of three days. 



The nova of 1866' was the first new star the light of 



