744 TABLE 846.— EMISSION LINES IN THE SOLAR CORONA* 



The following table was taken from Edlen's paper. 263 It summarizes the results of the 

 identification of 19 of the coronal lines caused by forbidden transitions. Fe X, XI, XIII, 

 XIV, XV ; Ni XII, XIII, XV, XVI ; Ca XII, XIII, XV ; A X, XIV. Two of these iden- 

 tifications, namely X 4359 attributed to A XIV and X 5694 attributed to Ca XV, are some- 

 what questionable and therefore these two identifications are given with a (?) in the 

 table. All these identified lines are caused by magnetic dipole radiation. 



The first column gives the wavelengths of the coronal lines taken from Mitchell's com- 

 pilation "* and reduced values from later work by Lyot. 208 The second column gives the 

 corresponding wave numbers. The third and fourth columns give the intensities as meas- 

 ured by Grotrian and Lyot respectively. The proposed identification is given in column five 

 and the transition probabilities in column six. The seventh and eighth columns give the 

 excitation potential and ionization potentials of the next preceding ionization stages. 



* Prepared by Edith J. Tebo, Harvard College Observatory. 



293 Zeitschr. Astrophys., vol. 22, p. 30, 1943. 



204 Handbook d'Astrophys., vol. 4, p. 324, 1929; vol. 7, p. 401, 1936. 



295 Monthly Notices, Roy. Astron. Soc, vol. 99, p. 580, 1939. 



t The ionization potential refers to the next lower stage. 



TABLE 847.— THE CEPHEID PERIOD-LUMINOSITY CURVE* 



* Prenared bv H. Shapley, Harvard University. 



2on Shapley, Harvard Bull., vol. 861, 1928. 



*" Shapley, Proc. Nat. Acad. Sci., vol. 26, p. 544. 1940. 



288 Kuiper, Astrophys. Journ., vol. 88, p. 453, 1938. 



SMITHSONIAN PHYSICAL TABLES 



