296 ASTRONOMY: H. SHAPLEY Proc. N. A. S. 
The clusters whose stars are included in this synopsis of absolute magni- 
tude are Messier 3, 5, 11, 13, 15, 30, 68; N. G. C. 4147, 7006. Their 
distances range between seven and seventy thousand parsecs ; the apparent 
magnitudes that correspond to zero absolute magnitude range between 
14.3 and 19.2. 
The available absolute magnitudes fainter than zero are less accurate 
than those for the brighter giants, and for many of the most distant 
TABLE I 
Data for Curves of Color Frequency 
(Tabulated quantities are numbers of stars) 
COLOR 
INDEX 
ABSOLUTE 
CM 
6 
(M 
d 
00 
d 
q 
CM 
CO 
00 
0 
MEAN 
MEAN 
PHOTOVISUAL 
I 
0 
d 
d 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
CM 
+ 
ALL 
COLORS 
MAGNI- 
COLOR 
MAGNITUDE 
0 
0 
+ 
0 
0 
0 
0 
0 
0 
0 
0 
TUDE 
INDEX 
0 
CM 
00 
0 
CM 
00 
d 
d 
0 
0 
0 
0 
1 
1 
d 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
+ 
-5.0 to -4.5 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
-4.5 to -4.0 
0 
0 
0 
1 
0 
0 
0 
1 
0 
0 
0 
0 
2 
-4.38 
+0.77 
-4.0 to -3.5 
0 
0 
0 
1 
2 
2 
2 
3 
3 
6 
1 
0 
20 
-3.74 
+ 1.11 
-3.5 to -3.0 
0 
0 
0 
0 
1 
5 
5 
7 
11 
13 
5 
2 
49 
-3.18 
+ 1.26 
-3.0 to -2.5 
0 
0 
1 
1 
7 
14 
13 
21 
25 
6 
1 
1 
90 
-2.77 
+ 1.04 
-2.5 to -2.0 
0 
0 
1 
2 
9 
17 
29 
29 
12 
1 
2 
0 
102 
-2.25 
+0.93 
-2.0 to -1.5 
0 
0 
1 
4 
22 
16 
39 
24 
3 
1 
0 
0 
110 
-1.76 
+0.82 
-1.5 to -1.0 
0 
4 
0 
10 
23 
60 
33 
13 
2 
0 
0 
1 
146 
-1.22 
+0.71 
-1.0 to -0.5 
1 
1 
16 
34 
18 
60 
77 
18 
1 
1 
0 
0 
227 
-0.72 
+0.67 
-0.5 to 0.0 
2 
54 
74 
51 
50 
104 
55 
8 
1 
0 
0 
0 
399 
-0.23 
+0.43 
All magnitudes 
3 
59 
93 
104 
132 
278 253 
124 
58 
28 
9 
4 
1145 
-1.18 
+0.69 
clusters the data for the fainter stars are very incomplete. The present 
study therefore is limited to stars brighter than zero magnitude, and for 
the luminosity curves it is restricted to the clusters Messier 3, 11, and 
13, for which we have published catalogues of magnitudes and colors 
complete to the adopted fainter limit. 
For intervals of 0.2 mag. in color index and of 0.5 mag. in absolute 
photo visual magnitude table I contains the number of stars from all 
nine clusters. Only seven of the 1152 stars fall outside the limits of this 
table. Their absolute magnitude and color indices are: 
- 5.45 +1.01 -2.77 +2.06 
-4.14 +1.23 -2.19 —0.52 
-5.(9 +1.00 - 1.03 —0.60 
-5.(1 +1.83 
