Further Observations on Nova Persei. 



399 



" Further Observations on Nova Persei. No. 3." By Sir Norman 

 Lockyer, K,C.B., F.B.S. Received Mav 17,— Bead June 20 

 1901. 



In the last paper* I gave an account of the observations of the 

 Nova made at Kensington between March 5 and March 25 inclusive. 

 The observations are now brought up to midnight of May 7. Between 

 March 25 and the latter date, estimates of the magnitude of the 

 Nova have been made on thirty-three evenings, visual observations of 

 the spectrum on twenty-five evenings, and photographs of the spectrum 

 on six evenings. 



The 10-inch refractor with a McClean spectroscope has generally 

 been used for eye observations. The 6-inch prismatic camera has not 

 been available for photographing the spectrum owing to the faintness 

 of the Nova,, but photographs have been secured by Dr. Lockyer with 

 the 30-inch reflector on the nights of March 27, April 1 and 12, and 

 by Mr. Fowler on March 26 and April 4. With the 9-inch prismatic 

 reflector the spectrum was photographed by Mr. Hodgson on March 30, 

 April 1 and 4. 



Since March 25 the magnitude of the Nova has been undergoing 

 further periodic variations, and although observations have not been 

 made on every night since that date, owing to unfavourable weather, 

 yet sufficient data have been gathered to enable a general idea of the 

 light changes to be obtained, and the few gaps can be filled up later 

 by other observers who experienced clearer skies on these occasions. 



The following table is a continuation of the observations for magnitude. 

 Columns (1), (2), and (3) denote the observations made by Dr. Lockyer, 

 Mr. Fowler, and Mr. Butler respectively, and Column (4) includes 

 other estimates made by Mr. Baxandall and Mr. Shaw. The numbers 

 in brackets represent the Greenwich mean time at which the observa- 

 tions (against which they are printed) were made, and refer to the 

 evening hours (p.m.), except where otherwise stated. 



Change of Brightness. 



Magnitudes of Nova Persei. 



March 26 . . 



27 ... . 



28 ... . 



30 .. .. 



31 .. .. 



(1) (2) (3) 



4 -2 (10. 30) 4 -2 (10 30) — 



3-9 42 — 



4 -2 F.E.B. 

 <5-0 H.S. 

 4-2 H.S. 



(4) 



5-3 5-3 

 — 4-2 



,, ox . . . . 



April 1 . . . . 



4-3 4-3 



4*4 — 4*4 



4-3 (7.0) 4-4 4-5 



# Page 230, supra. 



