Assuming that the mass of the system is equal to the mass of the Sun, the "hypothetical parallax" would be The magnitudes of the components are, according to Struve, 7'4, 76; and the approximate position of the star for 1880'0 is R.A. 19h 21m.7 Decl. +27° 8' It lies about 14° s.p. ẞ Cygni. The Orbit of y Corona Australis. By R. P. Sellors, B.A. The general equation of the apparent ellipse was found by Glasenapp's method, and the geometrical elements deduced therefrom by the formula of Kowalsky. The dynamical elements were determined from five equations of mean motion. The following is a comparison between all the measures I have been able to collect, and the positions computed from the above elements: Observer. ᎡᎪ. Log factor of Parallax. Corr. for Refraction. Observations of Brooks' Comet (d 1892) and Swift's Comet (a 1892) made at the Royal Observatory, Greenwich. The observations were made with the East, or Sheepshanks equatoreal, aperture 6.7 inches, by taking transits Greenwich Mean Appt. Comp. Brooks' Comet. N.P.D. Log factor Corr. for No. of of Parallax. Refraction. Comps. Appt. R.A. On Oct. 23 Swift's Comet was extremely faint and was only suspected; its close proximity to several faint stars increased the difficulty of accurate observation. Brooks' Comet on Oct. 23 was large and round, with decided central condensation. On Nov. 3 it was very faint owing to moonlight and mist. On Nov. 6 it was noted as fairly large, with a nucleus of 7.5 magnitude. |