SECRETARY'S REPORT 183 



and Satellites 1961 ol (Transit 4 A) and 1961 o2 (Injun Solar Radiation S) 

 for Aug. 5, 1961-Dec. 31, 1962, prepared by P. Stern. 

 No. 148, February 28, 1964 

 Catalog of precisely reduced observations: Satellites 1959 al (Vanguard 2), 

 1959 V (Vanguard 3), 1960 i2 (Echo 1 rocket), and 1961 51 (Explorer 9) 

 for July 1-Dec. 31, 1962; Satellite 1961 51 (Midas 4) for Mar. 9-Dec. 31. 

 1962; and Satellite 1962 ael (Telstar 1) for July 13-Dee. 31, 1962, prepared 

 by P. Stern. 

 No. 149, April 15, 1964 



Long-period effects in nearly commensurable cases of the restricted three- 

 body problem, by J. Schubart. 

 No. 150, April 22, 1964 



The temperature above the thermopause, by L. G. Jacchia. 

 No. 151, May 5, 1964 

 A catalog of positions and proper motions of 258,997 stars for the epoch 

 and equinox of 1950.0, by the Staff of the Smithsonian Astrophysical 

 Observatory. 

 No. 152, June 15. 1964 

 Temperature variations in the upper atmosphere during geomagnetically quiet 

 intervals, by L. G. Jacchia and J. Slowey. 

 No. 153, June 16, 1964 

 Catalogue of satellite observations: Satellites 1958 al (Explorer 1), 1959 al 

 (Vanguard 2), 1959 -ql (Vanguard 3), and 1959 tl (Explorer 7) for Jan. 1- 

 June 30, 1963, prepared by B. Miller. 

 No. 154, June 17, 1964 

 Catalogue of satellite observations: Satellites 1960 d (Echo 1), 1960 t2 (Echo 1 

 rocket), 1960 fl (Explorer 8), and 1961 51 (Explorer 9) for Jan. 1-June 30, 

 1963, prepared by P. Stern. 

 No. 155, June 18, 1964 

 Catalogue of satellite observations: Satellites 1961 ol (Transit 4A), 1961 o2 

 (Injun Solar Radiation 3), 1962 ael (Telstar 1), and 1962 /3/il (Anna IB) 

 for Jan. 1-June 30, 1963; Satellite 1962 vl (Cosmos 5) for Mar. 11-Apr. 30, 

 1963; Satellite 1962 /3t2 (Injun 3) for Jan. 16-June 30, 1963; Satellite 1962 

 Pvl (Relay 1) for Jan. 4-June 30, 1963; Satellite 1963 9A (Explorer 17) for 

 Apr. 6-June 24, 1963; and Satellite 1963 13A (Telstar 2) for May 11- 

 June 30, 1963, prepared by B. Miller. 

 No. 156, June 25, 1964 

 Baker-Nunn photography of the Syncom II fourth-stage ignition, by R. Citron 

 and L. H. Solomon ; and Tracking of Centaur (AC-2) , by L. H. Solomon. 



STAFF CHANGES 



Scientists who joined the Observatory staff during the year are 

 Dr. Henry F. Helmken, Dr. Craig Merrihue, and Dr. William G. 

 Elford, physicists; Dr. Richard R. Haefner, supervisor of computa- 

 tions operations; Douglas T. Pitman, chemist; Leendert Aardoom, 

 geodesist; Carlton G. Lehr and Yasushi Nozawa, electronic engineers; 

 and Dr. P. L. Bhatnagar, astrophysicist. 



Resignations during the year included those of Dr. Morton J. 

 Davies, Dr. Wolfgang Kalkofen, and Dr. Max Krook, physicists; 

 Dr. Joachim Schubart, celestial mechanician ; Richard C. Bruck, chief 



