40 CELESTIAL MECHANICS: LEUSCHNER 



(127) JOHANNA 



Discovered by Prosper Henry 1 at Paris, 1872, November 5. 



In B. J. 1875 a set of Elements A by Baillaud is published, based on 

 observations Nov. 9, 22, 28. 



Preliminary Elements B by Renan 2 are based on seven observations 

 for the opposition 1872-73. An ephemeris for 1874 April and May 

 is also published. An observation on April 17, 1874, shows corrections 

 to the ephemeris Aa +2 m 43 s , AS 16'. 



An improvement on Elements B is made by Renan 3 on the basis of 

 six normal places (1872-1874). The resulting Elements C represent 

 the normal places within +7".8 and 9".l. Renan states these differ- 

 ences are within the limits of error and Elements C may be considered 

 definitive. An ephemeris is then computed for 1876 September. 



Elements D are published by Bauschinger. 4 They are by Maywald 

 and are based on oppositions 1872, 1874, 1876, 1879. The special 

 perturbations of Jupiter and Saturn to 1890 are included. 



Renan's elements are published and used by B. J. 1882 to 1887. 

 Beginning with B. J. 1888, Maywald's elements are used. An empirical 

 correction was applied to the mean anomalie in 1913 by Berberich. 5 



A correction to the R. I. ephemeris 6 for 1918, November 23, is Aa 

 5 m .2, AS 20'. An improved ephemeris is published 7 for the period 

 1920, March 21 to April 21, from elements based on 6 oppositions, 

 1897-1908. Jupiter's perturbations are included. Representation 

 m .3. Osculation 1921, July 13. The correction to this ephemeris 8 

 from an observation 8 February 28, 1920, is Aa ^-O'M, AS 6'. 



Another ephemeris 9 for 1920 by P. Maitre is based on elements 

 published in Connaissance des Temps for 1915 with the mean anomaly 

 corrected, on the basis of observations in 1917 and 1918, AM 1.305. 



General perturbations applying Bohlin's method for this planet 

 have been published by D. T. Wilson 10 and similar perturbations with 

 Hansen's method, by M. Viljev. 11 



Olson 12 has published general perturbations of the first order by 

 Jupiter. The basic elements are those of Maywald. Jupiter mass 

 1:1047.568 (Bessel-Schur) . Method that of Hansen. Terms of 6th 

 to 8th order are below 1". No comparison with observations. 



REFERENCES 



'A. N. vol. 80, p. 239. 7 B Z der A. N. No. 11, 1920. 



a A. N. vol. 83, p. 349: C. R. vol. 8 B Z der A. N. No. 14, 1920. 



78, 1874, p. 1219. ' 8 C. O. M. No. 297. 



8 C. R. vol. 83, 1876, p. 567. 10 Ast. lakttagelser och Undersoknin- 



4 Veroffentlichungen R. I. No. 16. gar, Stockholm, vol. 10, No. 1. 



6 B. J. 1915, p. 27. "Bull. Soc. Astr. Russio. No. 22. 



*A. N. vol. 208, p. 14. "Swed. Akad. Handl., Stockholm, 



1895. 



