SECRETARY'S REPORT 173 



Observatory employs its network of Baker-Nunn cameras to photo- 

 graph a flare star repeatedly. The probability of successful obser^^a- 

 tion is good since several of the cameras can be used simultaneously. 

 During the same interval, one of several radio telescopes cooperating in 

 the program continuously observes the same flare star. The resulting 

 records are searched for nearly simultaneous optical flares and sudden 

 increases in radio signal. During the past year about 180 hours of 

 combined observations have been made. Correlations previously 

 found to exist between faint optical flares and radio events were con- 

 firmed by several major events- 



The continuing cooperative effort with Sir Bernard Lovell of the 

 Jodrell Bank Experimental Station, England, and Dr. Whipple and 

 Leonard H. Solomon of the Astrophysical Observatory has led to 

 further new evidence concerning optical flares and radio flares on 

 peculiar dwarf stars, such as TJV Ceti. A distinction between two 

 types of event has been made, with at least one analogy to solar phe- 

 nomena being drawn. Further, the coincidence in time between 

 optical and radio flares shows that the velocity of light is constant to 

 better than one part in 2 X 10^ over a range in wavelength exceeding a 

 factor of 2X 10^. Similar joint programs are being pursued with the 

 Division of Radiophysics, Commonwealth Scientific and Industrial 

 Research Organization, Sydney, Australia, and the Arecibo Iono- 

 spheric Observatory of Cornell University. 



Project Celescope," the satellite project to use television techniques 

 to survey the ultraviolet magnitude of stars, has finished its develop- 

 mental phase with completion of the prototype instrument. The proj- 

 ect next enters the critical phase during which the prototype undergoes 

 extensive environmental testing, and the instrument for flight on an 

 Orbiting Astronomical Observatory is fabricated to the proven proto- 

 type design. Overall aspects of this challenging undertaking have 

 engaged the attention of Dr. Whipple, Dr. Lmidquist, and Project 

 Scientist Dr. Robert Davis. The procedures for absolute calibration 

 of the four ultraviolet television photometers have been established by 

 Dr. Davis and Mr. Malaise. Preparations for automated data reduc- 

 tion and analysis are coordinated by Dr. Owen Gingerich. 



At wavelengths still shorter than ultraviolet light, projects are 

 underway at the Observatory to measure X-rays and y-rays from 

 astronomical sources. The most exciting experiment now in progress 

 is an attempt by Dr. Fazio and Dr. Henry Helmken of the Observatory 

 and Dr. D. Hill of M.I.T. to detect y-rays with energy greater than 10^^ 

 ev from the radio galaxy Cygnus A and from the quasi-stellar radio 

 sources. A large (28 ft. square) fixed parabolic mirror in conjunction 

 with a steerable plane mirror (40 ft. square) is being used to detect the 



See footnotes, p. 177. 



