58 •' Double Stars. 



DOUBLE STAES.— COLOURS OF STAES. 



BY THE REV. T. W. WEBB, A.M., E.R.A.S. 



It is now a considerable time since we have pointed ont any of 

 these interesting objects ; but we must not lose the present 

 opportunity of adding one more to our list before it gets away 

 into the twilight; not visible indeed to the naked eye, but 

 easily found at the present season. The pretty little constel- 

 lation, Corona Borealis, always readily distinguished by its 

 form, passes the meridian, at a considerable elevation, about six 

 o^ clock at the middle of this month, and consequently will be 

 verging toward the W. when our observations begin. Direc- 

 tions for finding its lucida a., or Gemma as it is sometimes 

 called, are given in connection with No. 35 of our " Double 

 Star List/-' at p. 134 of the Intellectual Observer, for Sep- 

 tember, 1862. If we have an equatorial stand, we have only 

 to sweep on the parallel of a a little towards the W. for the 

 star, which is but 10' further N. ; or with an ordinary altitude 

 and azimuth movement to move the telescope a little to the 

 right of a, and somewhat below it, in the direction in which a 

 is declining; then at a distance of 2 1°, which is the breadth 

 of a field of my 14 inch finder, we shall come upon a small star. 

 We shall pass by several gleaming points before we reach 

 it, but it is the first star in that direction large enough to 

 be at all conspicuous with my l^th inch aperture. It was 

 long before I could find it, from a mistake as to its nomencla- 

 ture. It is not, as I supposed, the 1 Goronce of Flamsteed, which 

 is duly entered in the larger star map of the S. D. U. K., and 

 lies further N. ; but, as Mr. Knott * pointed out to me, Goronce 

 1 of Bode, or No. 1932 of Struve, and will be, in our "Double 

 Star List "— 



124. The data, in Struve's Catalogue, as the mean of four 

 years, are, 5-6 and 6'1 (of his scale), 1"'622, 273 a -85. 1830-28. 

 Both very white ; with a suspicion, from discordant compa- 

 risons of magnitude, of variable light. Madler, however, 

 having found l"-536 and 278M7, 1839-52, and Secchi 1"'149 

 and 285 0, 37, 1856-401, the latter has suspected motion, 

 which has been confirmed by Dembowski, who gives 1"'180 

 and 290 o, 27, 1863*28. So that we may look upon this 

 very elegant little pair as a binary system — which, indeed, its 

 mere appearance would indicate. In crowded parts of the sky, 

 and with much inequality of magnitude, juxtaposition may be 

 naturally referred to mere perspective, and the probability 

 would be against the binary character of a very unequal 



* This gentleman's name was erroneously printed "Knox" in our last number. 



