Gore— ^ Catalogue of Binary Stars, (^c. 575 
IS'OTES. 
1. Struye, 3062. One revolution has now been nearly completed 
since it was discovered'in 1782 by Sir William Herschel, wbo measured 
it, 1782-65 : 319°-4. Schur's period of 112*644 years seems to be 
near the truth. Some recent measures are : — 
A list of measures by Dr. Doberck, from 1876 to 1882, will be 
found in the Transactions of the Eoyal Irish Academy, vol. xxix., 
part XIII. (1890). 
2. 0. Struve, 4. A binary star discovered by 0. Struve in 1844. 
From that year to 1887 the companion had described about 77° of its 
apparent orbit, the motion being retrograde, or in the order of decreas- 
ing position angles. An orbit was computed by Professor Glasenapp 
in 1889. The greatest difference between the observed and computed 
position angles {6o - 6c) is + 19°'4 at the epoch 1 874*7 1 (Dembowski). 
The computed distances do not agree ver)- well with the earlier 
measures. Professor Glasenapp says, "Dans une quinzaine d'annees 
on pourrait entreprendre une revision des observations afin d'obtenir 
une orbite plus exacte ; jusqu' d ce temps la ce travail serait peut- 
etre premature." 
Some recent measures are : — 
The latter measure was made with the 30-inch refractor of the 
Poulkova Observatory. 
3. 7} Cassiopeise. This well-known binary star has described about 
116° of its apparent orbit since its discovery by SirW. Herschel in 1779, 
the distance diminishing from about 11" to 4f". Dr. Doberck's orbit 
is perhaps the best hitherto computed. Sadler thinks that Duner's 
value of a "is much too large," and that it probably does not exceed 
8"'5. Assuming Struve's parallax of 0"-154, the combined mass of 
the components is from 5i to lOf times the mass of the sun varying 
E.I.A. PKOC, SEE. m., VOL. I. 2 T 
1882- 83 : 308°-14 
1883- 60 : 309 -83 
1887-104 : 310 -73 
1889-57 : 321 '1 
l"-52, Doberck. 
1 -69, Engelmann. 
1 -50, Tarrant (A.JST. 2899). 
1 -45, Burnham (A.^^. 2957). 
1880-57 
1887-93 
163°-00 : 0"-44, Burnham. 
141 -10 : (0 -30), H. Struve. 
