CHAPTER XIII. 
8629 Y CASSIOPEIA. 
R. A. 23b 58m 13S.8; Dec. + 55 ° l' 25" (1900). 
This variable was discovered by Mrs. Fleming in 1898 at Harvard, from the 
bright hydrogen lines in its third type spectrum. H. C. O. Circular, No. 24, 
states that there are 101 plates containing the field, so when these are measured 
the variation of the star will be thoroughly known. The brighter stars in the 
field were measured with the 6-inch in February and March, 1898, and the place 
of the variable relative to the stars A and B (Cambridge A. G. catalogue) found 
as given above. The stars b, e, and / were connected with the variable with the 
micrometer on the 40-inch in February, 1900. The star e was found to be double, 
about 13th and 14th magnitude, position angle 198°, distance 6".6. 
Visual comparisons of the variable began in February, 1898, a little too late 
to definitely fix the maximum, which the mean light-curve aids in placing at 
March 11, 9.4 magnitude on the Harvard scale. The decline following this maxi¬ 
mum was followed with the 6- and 12-inch telescopes, and at the minimum the 
star remained below the limit of the 6-inch for 91 days, from 1898 September 7 
to December 7. The next maximum, 1899 April 8, was well covered with the 
6-inch, and the variable was found at minimum with the 40-inch, 1900 January 
8 (minimum by mean curve, 1899 December 13). The adopted magnitude at 
the next maximum would be 9.6 or 10.6, according to the weights given to the 
discordant observations of June 15 and July 12. The probable course of the 
variations from October, 1900, to August, 1904, is shown by the broken line in 
fig. 38, fixed by the aid of the mean light-curve, guided by occasional observa¬ 
tions sufficient to give the number of the epoch. From August, 1904, regular 
comparisons fix the maximum of epoch 6 and the following minimum, and show 
that the adopted period, 410 days, is substantially correct. 
Table 108.—8629 Y CassiopElE. Standard Magnitude Stars. 
1900. 
Magnitude. 
Residuals. 
Star. 
B. D. No. 
R. A. 
Dec. 
Color 
P. DM. 
Catalogue. 
Measured. 
1 + m Cats. 
3 
Nights 
inter 
se. 
H.C.O. 
P. DM. 
H. 
P. 
H. 
P. 
C 
O 
+ 54 3109 
h m s 
00 00 30 
O / 
+ 55 09.2 
G- 
7. n 
7 °5 
7.29 
7.02 
+ 18 
- 3 
±4 
F' 
+ 55 3055 
23 5 * 53 
+ 55 170 
WG 
7.01 
6-57 
6.88 
6.61 
-*3 
+ 4 
±6 
G 
+ 55 3041 
23 49 02 
+ 55 56.0 
G 
7.48 
7.16 
7-43 
7.16 
- 5 
0 
±6 
Mean .... 
7.20 
6-93 
7.20 
6-93 
±12 
± 2 
±5 
* 7.5 
