Notes

Abstract

AT the anniversary meeting of the Royal Astronomical Society, on the 11th inst, Mr. Hind, president, in the chair, the gold medal was presented to Prof. Axel Möller, Director of the Observatory at Lund, in Sweden, for his investigations on the motion of Faye's comet. Prof. Möller's researches commenced in 1860, soon after attention had been directed to this comet by the offer of a prize for the accurate determination of its orbit by the Society of Natural Sciences of Dantzic, and they have been continued to the present time, the comet's track at each of the three subsequent returns in 1865.66, 1873, and 1880–81, having been predicted with a precision which has excited in no small degree the admiration of astronomers; indeed, at the re-appearance in 1873, M. Stephan's first observation at the Observatory of Marseilles, showed that the error of predicted place was less than six seconds of are, and after the last revolution, when the perturbations from the action of the planets were greater than in any previous revolution since the comet was first detected by M. Faye in 1843, tne agreement between observation and calculation was still very close. One important result of these investigations has been a striking confirmation, from the motion of Faye's comet, of the value for the mass of Jupiter deduced by Bessel from the elongations of the satellites, the two values according within the limits of their probable errors. Prof. Möller also carried back the accurate computation of the perturbations to December, 1838, so as to ascertain the effect of a pretty near approach to Jupiter in March, 1841, upon the previous orbit, and having done this he examined the probable circumstances of a very near approach of the two bodies near the passage of the node in 1816, to which attention had been drawn by Valz soon after the comet's orbit was fairly determined. Thus Möller's laborious investigations extend over a period of forty-three years, during which he has followed the motion of the comet with all the refinements of which the actual state of the science admits. It will be generally accorded that the medal has been well earned in Prof. Möller's case. The last occasion on which it was awarded for investigations of a similar kind was as far back as 1837, when the Astronomer-Royal presented the medal to Roseuberger for his researches on the motion of Halley's comet.