73 



Öfversigt af Kongl. Vetenskaps-Akademiens Förhandlingar 1899. N:o 2. 

 Stockholm. 



• Meddelanden från Lunds Astronomiska Observatorium. N:o 4. 



On the elements of the sun's rotation. 

 By C. A. Schultz-Steinheil. 



[Communicated 1899, February 8.] 



In Astronomische Nachrichten N:o 3543 I have with a 

 rough aproximation shown that, if we make use of Duner's 

 spectroscopical observations of the sun, it is possible to remove 

 the anoraalies in the time of rotation of the sun in clifFerent 

 latitudes under the supposition that the quantity i determined 

 by Sporer and employed by Dunér is somewhat inaccurate. 

 Now 1 have with the aid of Düner's observations determined i 

 and i2, assuming a uniform rotation of the sun, and found the 

 result satisfactory. On the foUowing pages I will give the de- 

 tails of this calculation. 



Let w be the velocity of the sun's true equator in km. per 



second and 



y = sin i cos Q 



z — sin i sin Q. 



where i = 7° and i3 — + 75°. It was my first object to search 

 for the corrections åx^ dy and dz. I also got aproximate values 

 of these quantities, but as the formulas employed were only 

 aproximate, I had then to determine the definite values x, y 

 and z^ which, however, proved to be impossible. Thence I con- 

 cluded that the values of i and 12, with which I began the cal- 

 culation, were so far remote from the true values, that aproxi- 

 mate formulas were unapplicable. For that reason it was ne- 

 cessary to make the whole calculation once more and determine 

 x^ i and £2 with exact forraulas, of which I now will give a 

 deduction. 



