CHAPTER II. 
103 T ANDROMEDA. 
R. A. oh 17m 10.0 s ; Dec. +26° 26' 27" (1900). 
The variability of this star was discovered by Anderson in 1893 and observations 
began soon after the receipt of the Astronomische Nachrichten No. 3202 contain¬ 
ing the announcement. The literature concerning the star is given so completely 
in the forthcoming catalogue of the Gesellschaft committee, that it is unnecessary 
to repeat it here. The light changes are unusually regular, the maxima and minima 
being both well defined. At present the period seems to be lengthening. 
The comparison stars have been measured with the photometer, the residuals 
being: For the catalogue stars, ±0.03; for the stars measured with the 6-, 12-, 
and 40-inch, respectively, ±0.08, ±0.09, and ±0.11 magnitude. 
Detailed explanations follow for the tables and figures giving the photometric 
and visual results for this star. For the other eleven variable stars given in 
Chapters III to XIII explanations are only given for the few particulars in 
which the tables differ from those for T Andromedae. The arrangement of 
the tables is as follows: First, the data for the identification of the comparison 
stars with a summary of the magnitude results used in the reductions, Tables 5, 6, 
and 7; second, the photometric measures in detail, Table 8; third, reduction 
constants and summary of photometric results, Tables 9 and 10; fourth, visual 
observations of the variable, with reductions to photometric magnitude, and 
residuals from the mean light-curve, Table 11; fifth, data for formation of 
mean light-curve, with residuals for the twelve parts of each separate curve. 
Table 12; sixth, observed maxima and minima, Table 13. 
Table 5.—Standard Magnitude Stars. 
1900. 
Magnitude. 
Residuals. 
Star. 
B. D. No. 
R. A. 
Dec. 
Color 
P. DM. 
Catalogue. 
Measured. 
From Cats. 
3 
Nights 
inter 
se. 
H. C. 0 . 
P. DM. 
H. 
P. 
H. 
P. 
A 
O 
+ 25 34 
h m s 
0 14 10 
O / 
+ 25 54.7 
GW+ 
7.67 
7.76 
7.61 
7.69 
- 6 
- 7 
±4 
B 
+ 25 29 
0 13 18 
+ 25 36.1 
W+ 
7.21 
7.42 
7-47 
7 55 
+ 26 
+ 13 
± 2 
a 
+ 26 40 
0 16 18 
+ 26 23.7 
WG + 
8.20 
8.12 
7.98 
8.06 
— 22 
- 6 
±3 
Mean .... 
7.69 
7-77 
7.69 
7-77 
±18 
± 9 
±3 
Table 5 gives, for the standard magnitude stars, the Bonn Durchmusterung 
numbers, the position for 1900, the Potsdam color, and the catalogue magnitudes 
