Determination of the Elements of 

 the Sun's Spin. 



by 



S. Hirayama, Rigakushi. 



Since the discovery of sun-spots by Fabric-ins and Galileo, the 

 elements of the rotation of the sun, thai is, the position of the sun s 

 axis and its period of rotation, have been determined by many 

 astronomers. These results arc tabulated in rlouzeau's Vade-Mecnm 

 de l'Astronomie .and differ great I y with the different observers. The 

 various values of the inclination of the sun's equator to the ecliptic 

 lie between <i c ! and 8°, and those of the longitude of the node betw< en 

 60 and 80°. The two most reliable results were obtained by Mr. 

 Carrington and Dr. Spörer respectively, more than twenty years ago. 

 Recently Dr. Wilsing has determined the elements from the periods 

 of rotation of a single spot, [f / is the inclination of the equator of 

 the sun to the ecliptic, and N, the longitude of the ascending node, 

 the results obtained bv these three authorities are as follows : — 



( 1) Houzeau, Vade-Mecmn de l'Astronomi >.. § 162 Rotation pp. 4! 1. 



Carrington, Observations of the spots on the sun from 1853 to 1831 pp.244. 

 (3) Spörer, Beobachtungen der Soanenflecken zu Anclam (1874). 



(•I-) Wilsiag, Neue Bestimmung der liotationselemente der Sonne 1884. Astr. Nach. Bd. 

 107 pp. 277. 



