

KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 60. N!0 8. 57 



;r S p. and the mean parallax of the nova? in the Milky Way with ^ nov ., and M and m 

 signify the absolute and the apparent mean quantisy for the novse in the Milky 

 Way, and 31' and m' the corresponding quantities for the novae in the spiral ne- 

 bulse, we obtain, according to (1): 



-3* max. = W»' ma x. + 5 + 5 log jr Bp ., 

 M max . = m m ax. + 5 + 5 log 7T nov . 



Supposing that the absolute maximum magnitude of the novae in the Milky 

 Way is on an average equivalent to the same quantity for the novee found in the 

 spiral nebulös, or: M' max . = M max . , we thus obtain: 



log ^sp. = log ~nov. + - (Wmax. ~ W,' ma x.). (15) 



From the table we find the mean of the maximum magnitude of the 18 novse 

 = 15"\i. As to :r nov .. we will first take into consideration the direct parallax-measure- 

 ments existing for four galactic nova3. 



Nova Persei Nova Lacerta; 



Itabs. ~abs. 



f 0" } 009 ± 0" 5 004 VAN MaäNEN 120 + 0" 5 013 ± 0",012 SLOCUM & MlTCHELL 217 



+ 0,028 ±0,020 Hassenstein 7 "' -0.oo5 ±0,020 Balanowsky 12 



— 0,003 ± 0,023 Chase 40 + 0",oos ± 0",oio 



+ 0.03G ±0,010 Bergstrand 19 



+ 0,007 ± 0,004 KtJSTNER 109 



+ 0",010 ± 0",003 



Nova Geminortim P Cygni 



~abs. "abs. 



+ 0",012 ± 0",007 SLOCUM & MlTCHELL'-' 17 — 0" ; 0U ± 0",008 SLOCUM & MlTCHELL 217 



— 0,013 ±0,013 Miller 129 



+ 0",oo6 ± 0",oor, 



These nova3 had a maximum magnitude of 0,o, 3,7, 5,o and 3. o respectively, or 

 on an average 2 m .9. We find their mean parallax to be 0",oo68 ± 0,oo25. 



The scanty data existing for the proper motions and radial velocities give, 

 from 8 novae, jx m = 0",o4 and V m = + 20 km y S ec. , from which follows 7r nov . = 0",ooeo 

 ± 0",oo4o, agreeing closely with the value obtained from the parallax-measurements. 

 As this value corresponds to a mean w max . of 2 W .5, we shall assume that for w max . = 2 m ,7, 



"nov. = 0",00C6 ± 0",0020. 



We then obtain according to the above formula: 



^sp. =0",0000218. 

 K. Sv. Vet. Akad. Handl. Band 60. N:o 8. 8 



