GrORE — On Suspected Variable 8 tars. 379 



No. 509. 17 Draconis.— 5^ Lalande (30366) ; 5 Harding; 16 and 

 17 Draconis are together rated 4-5 by Heis. It is a double star, 

 6, 6'5 : 115°-7: 3"-8, Struve, who considers the components alternately- 

 variable. Pritchard gives 17 Draconis =5-22, and 16 = 5-07 (1882-717). 



IS'o. 510. Birmingham 391 Ophiucii. — Birmingham's observations. 

 1872-1876, vary from 9 m. to invisibility in his 4|^-inch telescope. 

 The colour also seemed to vary. 



No. 511. I Ophiucii. — 4 m. Sufi; 4^ Lalande and Bessel; 4-1 DM; 

 4-5 Argelander and Heis; 4-4 Gould (at Albany), and 5-0 at Cordoba. 

 Gould suspects variation, although the star is included in his Stand- 

 ards of Magnitude {U.A., p. 30) ; 4-12 Pritchard (1882-475). 



No. 512. - ScoRPii. — A star believed by Gould to be variable. It 

 was observed on the meridian at Cordoba as 6^ m., 1874, August 24; 

 but seen only 8|- m., 1873, Aug. 11 and 19. It lies closely np 12 

 Scorpii {U.A., p^ 286). 



No. 513. 24 Ophiucii = Lalande 30756. — 6 m. Lalande and Hard- 

 ing. Not given by Heis, Behrmann, or Hoiizeau ; 5-9 Gould; 5|- 

 Franks; "white," April 27, 1878; 7-6 Cape Catalogue (1879-26). 



No. 514. Lacaille 7057 Ar^. — 6|-Lacaille; 6 Brisbane; 7 Taylor; 

 7-6 Cape Catalogue (1875-57). Gould suspects variation, and says 

 "numerous estimates of the magnitude vary from 6-5 to 7-3." 



No. 515. 30 Ophiuch (-Lalande 30924).— 5^ m. Lalande; 5 

 Harding, Argelander, and Heis; 5-8 Yarnall. The Cordoba estimates 

 vary from 5*1 to 5-9. It is Birm. 399 (" yellow orange "). 



No. 516. 20 Draconis. — A close double star 7, 7i : 243°-7 : 0"-7 

 (1839); Bumham 213°-7 : 0"-20 (1880). Admiral Smyth remarks 

 {Bedford Catalogue, p. 379), "he (Sir W. Herschel) says the compo- 

 nents of this object were considerably unequal, whereas they are 

 now so nearly of the same magnitude, that it was only after much 

 comparison that I felt inclined to place the comes in the sp quadrant. 

 Can it be variable ? ' ' 



No. 517. 5749 B.A.C. Hercults = 32 Ophiucii.— 5 m. Lalande 

 (31037); 5 m. Argelander; 6-7 Houzeau (1875-29); 6 m. Pranks; 

 "pale orange," April 27, 1878. 5-11 H.P. 



No. 518. /x Draconis. — 4 m. Ptolemy, Tycho Bi^ahe and Hevelius; 

 5 m. Sufi; 5 TJlugh Beigh; 4 and 5 m. Harding; 5 Groombridge ; 4 

 Piazzi ; 5-4 Argelander and Heis ; 6 m. Houzeau. Sir W. Herschel 

 gives fx. g and 30, /x. ; 5 m. Pranks, May 3, 1878 [private letter) ; 5-00 

 Pritchard (1882-717). This star is probably variable, as pointed out 

 by the E-ev. S. J. Johnson and M. Plammarion. I have several times 

 observed it to be rather below than above 5 m., and have never seen 

 it any tiling a])proaching in lustre a 4 m. star. April 2, 1884, I found 

 fjL two steps brighter than 30 Draconis (5 m. Heis), 



E.I. A. PROC, SER. II., VOL IV. SCIENCE. 2 



