of a new Variable Star, 16-' 



further confirmation, compare two of the mofl: di^ant of 

 them, v'i%. Sept. 29. 22 h. and Nov. 20. 6 h. which interval I 

 find contains fix periods, each of 12 d. 20 h. ~. 



I have it in my intention to pUrfue the fubje£l further, and 

 when I have got a fullicient number of obfervations, it will 

 be eafy to determine the period with greater exadnefs, and 

 alfo at the fame time to afcertain the other particulars of the 

 variation with more precifion. in the mean while I wifli that 

 this account may be confidered as being yet imperfect ; but I 

 was induced to fend it in its prefent ftate, in hopes that other 

 aftronomers may contribute by their obfervations to the eluci- 

 dation of this phicnomenon. 



As /3 Lyrae is a quadruple ftar, N° 3. of Mr. Herschel's 

 Vth Clafs of Double Stars *, I was defirous to fee if any of 

 the fmall flars near it would be afFe(51:ed by its different changes ; 

 but they feemed not to fuffcr any alteration, either when it 

 was at its greatefl or at its leafl brightncfs. I attended to this 

 the more particularly becaufe the lofs of the flar's light was 

 very confiderable, and thephaenomenon feemed to be occafioned 

 by a rotation on the ftar's axis, under a fuppofition that there 

 are feveral large dark fpots upon its body, and that its axis is 

 inclined to the earth's orbit. 



I muft not omit mentioning here that Mr. Herschel, 

 amongfl thofe ftars v/hich he fuppofes to have undergone an 

 alteration, reckons (3 or y Lyrae ; becaufe he obferved that y was 

 much larger than (3, whila Flam^teed marks both of the 

 fame magnitude -f*. It may alfo be added, as fliewing that (3 

 Lyrae varied in former times, that Hevelius, in his Catalogue, 

 differs from Flamsteed, and marks y of the third magnitude. 



* Phil. Tranf. for 1782, p. 147. 

 t Phil. Tranf. for 17B3, p. 256. 



Y 2 and 



