54 



KNUT LUNDMARK, GLOBULAR CLUSTERS AND SPIRAL NEBUL.E. 



nebulse, have found a great number of faint novse in them, and at present there 

 are no less than 18 objects known, which are evidently to be considered as novse, 

 appearing in spiral nebulse. 



There cannot be any doubt regarding the fact that these stars are really 

 situated within the spiral nebulse, as there is no possibility of assuming that 11 

 novse should be seen just in the direction of the Andromeda nebula, whereas no novse 

 have appeared in its neighbourhood. On the other hand, it can by no mcans be 

 regarded as a certain fact that the stars tabulated above are really novse, but the 

 hypothesis is near at hand that we have here to deal with variables of long period. 

 In order to contribute to the solution of this question, I have considered it appro- 

 priate to try to derive the light-curves in the cases where sufficient observations are 

 at hand. The best-observed står of all in the table is the Nova Andromedse 1885. 

 I have laid as a basis for its light-curve the following series of observations. 



Observer 



Number 

 of obser- 

 vations 



Observed 



References 



Backhouse 



7 



1885 Sept. 1— Oct. 1 



M. N. 48: 108—09 





Bakhtjyzen 



5 



Sept. 1— 15 



A.N. 112:323 





Baxendell J. & J. 



27 



Sept. 3— Nov. 8 



Observatory IX: 94 — 95 





Charliee 



4 



Sept. 2—17 



A. N. 112: 389, 391 





COPELAND 



29 



Sept. 1—1886 Febr. 2 



M.N. 47:49 





Engelmann 



21 



Sept. 1— Nov. 18 



A.N. 1 12: 323-326; 113: 269- 



-70 



Espin 



11 



Sept.27— 1886 March 6 



Observatory IX: 156—57 





Franz 



12 



Aug. 31— Dec. 1 1 



A. N. 118: 123—24 





Hagen 



24 



Sept. 3 -Sept. 22 



Sid. Mess. IV: 286 





Hall 



10 



Sept. 29— 1886 Febr. 7 



Amer. Journ. of Science 1886 



299 



Hartwig 



23 



Aug. 19— Oct. 19 



A.N. 723:21,387 





Muller 



1(5 



Sept. 2— Oct. 13 



A. N. 113: 23 





Pritchard 



17 



Sept. 7— Oct. 16 



M.N. 46: 18-19 





Parkhurst 



40 



Sept. 1— Nov. 4 



Sid. Mess. V: 90 





Radcliffe 



35 



Sept. 9- Dec. 10 



M.N. 46:56—57. 





No very high degree of accuracy may be expected from these observations, 

 because, as a matter of course, they were rendered considerably more difficult by 

 the bright nebulous background. Considerable systematic differences also appear 

 between the different observers, owing to the use of various scales and instruments. 

 Graphically we have derived systematic corrections for the different series, whereupon 

 they have been reduced to Parkhurst's photometric system whose magnitudes will 

 evidently agree with the Harvard visual scale. I have not assigned different weights 

 to the different series of observations. Nor have I considered it appropriate to give 

 to the measurements performed with the Zöllner or wedge photometer (Prttchard 

 and others) parenses any greater weight than is given to the estimations, considering 

 the uncertainty of the determinations brought in by the existence of the light nebulous 

 background. 



