THE 



EDINBURGH NEW 

 PHILOSOPHICAL JOURNAL. 



On Double Stars, By M. Ahago. 



Many of our readers are probably aware that L? Academic 

 des Sciences has recently conferred its prize-medal on Sir John 

 Herschel, for his investigations concerning double stars. This 

 occurrence naturally directs attention to many curious inves- 

 tigations. Thus it may be inquired, what are we to under- 

 stand by double stars, and triple and quadruple ? and how is it 

 that these multiple stars have suddenly become so much the ob- 

 ject of assiduous research in the observatories of both hemi- 

 spheres ? Finally, what results do astronomers expect to de- 

 duce from the observation of these stars ? These are some of 

 the many inquiries which are involved in this subject; and we 

 shall now proceed to discuss them in a popular form, freeing 

 them as much as possible, if not from all mathematical techni- 

 calities, at least from such calculations as cannot be pursued 

 without a familiar acquaintance with the formulas of spherical 

 trigonometry, and the elliptical motions of the planetary system. 



L What is to be understood by double Stars ? 



Astronomers give the name of double, triple, quadruple, &c. 

 stars, to groups of two, of three, or of four stars, which appear 

 very near each other. 



VOL. XVIT. NO. XXXIII. — JULY 1834. A 



