1892.J Note on the New Star in Auriga. 467 



X Aurigse (mag. 5'0), but in that taken on February 23 it is not 

 brighter than the companion to this star, which is fainter than 6th 

 magnitude. No marked diminution in brightness was noticed before 

 February 22. 



The colour has not appreciably changed since the star was first 

 observed. 



Photographs of the spectrum were attempted on all the dates 

 named. Those of February 11, 12, 16, and 23, however, were insuffi- 

 ciently exposed, but they show that the dark lines were still more 

 refrangible than the accompanying bright ones, and that the same 

 lines were present as in the previous photographs. A plate was 

 exposed for 2 hours 35 minutes on February 24, but no impression 

 was obtained. The photograph taken on February 13 is identical 

 with those referred to in the notes which I have already commu- 

 nicated to the Society. In the three photographs of February 22 

 there appears to be a slight diminution in the intensity of the H and 

 K lines, but otherwise there is no decided change. 



There is no evidence of revolution during the twenty days of 

 observation. In all the photographs the dark lines are more refran- 

 gible than the bright ones, and the relative velocity deduced from 

 those of February 3, 7, 13, and 22 appears to be about 600 miles per 

 second. As this only represents the velocity in the line of sight, we 

 are still ignorant of the real velocities of the two bodies. The con- 

 stant relative velocity indicated by the displacement of the bright 

 and dark lines may be regarded as confirming the supposition that 

 two meteor-swarms or comets have collided, the velocities being so 

 great, and the masses so small, that neither was captured by the 

 other. 



The relative velocity of 600 miles per second seems at first sight 

 to be abnormally great, but, if we regard each of the component 

 swarms as moving at the rate of 300 miles per second, the velocities 

 are quite comparable with those of other bodies in space. The star 

 1830, Grdombridge, for example, moves at the rate of 200 miles per 

 second across the line of sight, and its real velocity may be much 

 greater. 



Eye observations have been made on every possible occasion. The 

 chief variations from those previously reported are the general fading 

 of the continuous spectrum and the consequent unmasking of the 

 lines between b and D. Micrometric measures of four new lines in 

 this region were made by Mr. Fowler on February 23 and 24. These, 

 with the other lines observed at Kensington in the region F to C, 

 are shown in the table which follows. The corresponding lines 

 observed in the spectra of new stars which have previously appeared, 

 and those in the spectra of some of the bright line stars, are added for 

 comparison. 



