62 



CELESTIAL MECHANICS: LEUSCHNER 



/ J7 / Algiers 12 on May 6, 1921. This observation gave a correction to the 

 ephemeris published in Kleine Planeten of +7 m -0 in right ascension 

 and 80' in declination. 



In A. N., vol. 215, p. 249, A. Wilkens has published an article, "Uber 

 die Sakularen Veranderungen der Grossen Achsen der Bahnen der 

 Planeten der Jupiter Gruppe." 



In A. N., vol. 175, p. 89, Charlier gives a brief discussion on the 

 orbits of the Trojan group, regarding their motion about the libration 

 points. 



In A. N., vol. 206, p. 235, A. Koref outlines his investigation regard- 

 ing the motion of Hector. His preliminary work is based on eighteen 

 normal places (1907 to 1914). The investigation will be completed 

 when observations of 1918 and 1919 are available. 



REFERENCES 



'A. N. vol. 174, p. 63. 



a A. N. vol. 175, p. 14. 



' A. N. vol. 177, p. 123. 



4 A. N. vol. 180, p. 327. 



6 Publikationer og mindre Meddel- 

 elser fra Kobenhavns Observatorium 

 No. 6. A. N. vol. 188, p. 395. 



* Publikationer og mindre Meddel- 

 elser fra Kobenhavns Observatorium 

 No. 8. 



7 Publikationer og mindre Meddel- 

 elser fra Kobenhavns Observatorium 

 No. 12. 



8 In manuscript (Berkeley). 



9 A. N. vol. 201, p. 335. B. A. J. 

 1917. 



10 Eph. der Kleinen Planeten, 1916, 

 p. 17, p. 77, p. 93, p. 97. 



"Cir. O. M. No. 480 (1921). 



"Cir. 0. M. No. 171, second series. 



TABLE 16. Elements (624) Hector (1907 XM) 



