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THE TEIPLE STELLAR SYSTEM 'C VIRGO AND 2 1757. 
ByR. T. a. Innes. 
(Received November 14, 1913.) 
The well-known double-star S 1757, which is a probable binary pair 
with a period of about 300 years, is 25^- 7 preceding and 17' N. of ^ Virgo. 
According to Boss's Preliminary General Catalogue of Stars 4 Virgo has 
an annual proper motion as follows : — 
fia = -0^-191 = + 0"-034. 
On a great circle this is 0"'288 towards 276°'8. 
Within the errors of observation, this also appears to be closely the 
proper motion of S 1757. The observations found and reduced to 1900, 
both without and with proper motion, are as follows : — 
Name. 
Date. 
Obs. 
Without P.M. 
With 
P.M. 
Without P.M. 
With 
PM. 
1798-3 
1 
13h 29'" 11^-91 
9^97 
+ 0° 11' 50" -7 
54"-l 
1800-0 
11 -75 
9 -84 
53 -1 
56 -5 
1822-3 
1 
11 -88 
10 -40 
47 -1 
49 -7 
1825-4 
4 
11 -58 
10 16 
51 -9 
54 -4 
1840-0 
11 -20 
10 05 
50 -9 
52 -9 
1843-6 
4 
11 13 
10 -05 
53 -0 
54 -9 
Bond 
1855-4 
1 
10 -52 
9 -67 
52 -3 
53 -8 
1861-4 
1-2 
10 -83 
10 -09 
53 -7 
55 -0 
1870-8 
10 -76 
10 -20 
53 -0 
54 -0 
1875-6 
4 
10 -71 
10 -24 
52 -8 
53 -6 
1884-4 
2 
10 -53 
10 -23 
53 -0 
53 -5 
1889-0 
3 
10 -38 
10 17 
53 -1 
53 -5 
1892-0 
10 -43 
10 -28 
53 -0 
53 -3 
1895-6 
4 
10 -35 
10 -27 
53 -9 
54 -0 
1902-9 
4 
10 -27 
10 -33 
53 -6 
53 -5 
In cases where the original star catalogues were not available, the data 
were taken from either the Cincinnati Publications (Porter) or the A.G.C. 
(Nicolajew). This table seems to be fairly conclusive that these three 
stars form a ternary system, but S 1757 has perhaps a smaller proper 
motion in right ascension than 4 Virgo. 
The Harvard photometric magnitude of 4' Virgo is 3'44 and its 
