41 



20 Vulpeculae. 



N. G. C. 6885 ; u,,,, = 20''7-.6, d,,,^ = 26°J()', /> = - 5°, / = 3i°. 



H. ScHULTZ. Micrometrisk bestamning af 104 stjernor inom 

 teleskopiska stjeriigruppen 20 Vulpeculae. Koiigl. Sveriska Vetenskaps- 

 Akademiens Haudlingar, Baudot IJ, N°. 3, 1873. 



The magnitudes have been determined by a photometer in accordance 

 with Ahgelander's scale. 



A. DoNNER nnd 0. Backi,und. Positionen von 140 Sternen des 

 Sternhaufens 20 Vulpeculae nacli Ausmessungen photographischer 

 Platten. Bulletin de I'Acad. Imp. des Sciences de St. Pétersbourg, 

 Série V, Volume II, pag. 77-92, 1895. 



Measurements of 2 plates taken by Donner at Helsingfors. The 

 magnitudes were taken from Shilow. 



M. Shilow. Grössenbestimmung der Sterne im Sternhaufen 20 

 Vulpeculae. Bulletin etc. ut supra, pp. 243-251. 



The magnitudes of the 140 stars, the position of which was deter- 

 mined by DoNNER and Backlund, were found by measuring the 

 diameters of the images. As standards those 100 magnitudes were 

 used that Schultz had determined already. Shilow uses Charlier's 

 formula m = j; — y\og D — zD. The probable error of a difference 

 ?rt— ?/?scHULTz is =t 0«.25. 



We have not reduced the magnitudes based on Argelander's scale, 

 to the Harvard scale, because Shilow's magnitudes differ considerably 

 from those of Schultz. We find for the parallax from 7 determinations: 



;r = 0".005 ± 0".001. 



Messier 5. 



N. G. C. 5904; «,,„„=15/'13'«.5, ff,,„„=:+2°27', /;=+45°, /=r333°; 

 class: 6' 3. 



M. Shilow. Positionen von 1041 Sternen des Sternhaufens 

 5 Messier, aus photographischen Aufnahmen abgeleitet. Bulletin de 

 I'Acad. Imp. des Sciences de St. Pétersbourg, Série V, Vol. VIII, 

 pag. 253-312, 1898. 



Measurements of 2 plates, taken resp. by Belopolsky and Kostinsky. 

 The magnitudes have been determined in a rathei- inaccurate manner, 

 viz. by comparing the diameters with the images of stars of 20 

 Vulpeculae, the magnitudes of which are known. 



S. I. Bailey. Variable Stars in the Cluster Messier 5, Annals 

 Harvard Observ., Vol. 78, Part. II, 1917. 



Ninety-two stars are dealt with. For 72 the period is mentioned. 



