Orbital elements of selected visual binaries
P = orbital period, in years; T = date of periastron, year and decimals; a = semi-major axis of orbit, arcseconds; e = eccentricity of orbit; i = inclination of orbit to plane of sky, degrees; peri = argument of periastron (usually indicated by a lower-case Greek omega, ω), degrees; node = PA of ascending node (usually indicated by a capital Greek omega, Ω), degrees.
These elements can be entered in this BASIC program to find the separation and position angle of each pair for any required date.
The ADS number (left column) is that given in R. G. Aitken’s New General Catalogue of Double Stars, which extends to declination –30°.
ADS
number
Star
RA
h   m
dec
°   ’
Magnitudes
P
(years)
T
a
e
i
°
peri
ω
°
node
Ω
°
17175
85 Peg
00  02.2
+27  05
5.8
8.9
26.280
2015.7
00.83
0.38
49.00
96.00
290.00
434
Lambda Cas
00  31.8
+54  31
5.3
5.6
245.70
2025.54
00.448
0.689
53.60
301.00
17.60
520
BU 395
00  37.3
–24  46
6.2
6.6
25.020
1998.78
00.675
0.218
78.60
318.10
291.980
671
Eta Cas
00  49.1
+57  49
3.5
7.4
479.270
2369.2
12.040
0.497
35.60
269.80
278.00
755
36 And
00  55.0
+23  38
6.1
6.5
167.510
1956.19
00.984
0.306
44.57
358.62
173.66
1538
STF 186
01  55.9
+01  51
6.8
6.8
166.400
205.5
01.023
0.721
73.80
220.10
42.20
1598
48 Cas
02  02.0
+70  54
4.7
6.7
61.140
2025.49
00.614
0.355
16.70
19.50
48.20
1615
Alpha Psc
02  02.0
+02  46
4.1
5.2
1947.000
2180
08.3
0.78
105.20
227.10
18.70
1631
10 Ari
02  03.7
+25  56
5.8
7.9
325.000
1931.6
01.39
0.59
51.00
165.00
20.50
2402
Alpha For
03  12.1
–28  59
4.0
7.2
268.200
1947.4
04.0
0.74
81.50
43.00
117.40
2616
7 Tau
03  34.4
+24  28
6.6
6.9
522.160
1911.62
00.625
0.679
157.20
238.10
13.00
2799
STT 65
03  50.3
+25  35
5.7
6.5
61.20
1998.30
00.442
0.628
84.70
340.30
26.40
5423
Alpha CMa
06  45.1
–16  43
–1.5
8.4
50.130
2044.70
07.50
0.591
136.34
149.16
45.40
5400
12 Lyn AB
06  46.2
+59  27
5.4
6.0
73300.
2138
02.6
0.43
118.30
64.50
40.40
5514
14 Lyn
06  53.1
+59  27
6.0
6.5
316.20
1961.99
00.614
0.441
64.70
170.30
51.00
6175
Alpha Gem
07  34.6
+31  53
1.9
3.0
459.80
1958.7
06.755
0.336
114.60
250.50
41.20
6420
9 Pup
07  51.8
–13  54
5.6
6.5
23.330
1985.92
00.618
0.765
80.82
253.64
282.65
6650
Zeta Cnc AB
08  12.2
+17  39
5.3
6.3
59.430
1988.95
00.853
0.314
173.60
239.20
67.70
6650
Zeta Cnc AB–C
08  12.2
+17  39
5.1
6.2
735.100
1801
08.9
0.62
119.60
295.20
157.70
6914
BU 208
08  39.1
–22  40
5.4
6.8
123.000
1986.6
01.705
0.33
82.90
309.20
31.80
I 314
08  39.4
–36  36
6.4
7.9
66.500
1992.2
00.527
0.86
102.00
341.00
55.70
Delta Vel
08  44.7
–54  43
var.
5.1
146.9700
2000.78
02.002
0.482
105.60
8.50
344.70
6993
Epsilon Hya
08  46.8
+06  25
3.5
6.7
371.900
2085.9
03.10
0.47
46.90
256.90
162.50
7307
STF 1338
09  21.0
+38  11
6.7
7.1
303.270
2023.25
01.336
0.254
29.90
191.90
137.30
7390
Omega Leo
09  28.5
+09  03
5.7
7.3
117.970
1959.22
00.860
0.562
65.35
302.54
325.98
Psi Vel
09  30.7
–40  28
3.9
5.1
34.100
2003.97
00.810
0.431
57.20
46.20
289.10
7545
Phi UMa
09  52.1
+54  04
5.3
5.4
104.600
1987.52
00.329
0.436
19.40
33.30
132.50
7555
Gamma Sex
09  52.5
–08  06
5.4
6.4
77.820
2035.47
00.397
0.736
141.10
303.3
194.70
7724
Gamma Leo
10  20.0
+19  51
2.4
3.6
554000
2304
03.10
0.90
49.000
30900
347000
7846
BU 411
10  36.1
–26  41
6.7
7.8
159.300
1948.3
00.867
0.759
128.50
41.70
148.90
8119
Xi UMa
11  18.2
+31  32
4.3
4.8
59.890
1995.06
02.504
0.404
122.19
126.96
100.94
8148
Iota Leo
11  23.9
+10  32
4.1
6.7
184.500
1948.4
01.92
0.54
127.60
142.80
54.40
8197
STT 235
11  32.4
+61  05
5.7
7.6
72.930
1981.91
00.793
0.398
46.83
132.57
81.41
8539
STF 1639
12  24.4
+25  35
6.7
7.8
421.300
1892.9
01.07
0.90
112.40
17.90
147.70
8573
BU 28
12  30.1
–13  24
6.5
9.6
150.940
1946.09
01.395
0.702
29.90
60.90
112.80
Gamma Cen
12  41.5
–48  58
2.8
2.9
83.570
2014.82
00.869
0.793
113.70
187.90
2.60
8630
Gamma Vir
12  41.7
–01  27
3.5
3.5
169.100
2005.51
03.639
0.882
149.46
255.00
35.34
8695
35 Com
12  53.3
+21  15
5.2
7.1
 486.300
1929.2
01.35
0.14
34.10
51.30
60.50
8974
25 CVn
13  37.5
+36  18
5.0
7.0
245.000
2110.4
01.01
0.83
159.50
140.90
64.80
Alpha Cen
14  39.6
–60  50
0.0
1.3
79.910
1955.66
17.66
0.524
79.32
232.3
204.75
9343
Zeta Boo
14  41.1
+13  44
4.5
4.6
125.240
2023.82
00.825
0.980
126.00
61.80
176.50
9413
Xi Boo
14  51.4
+19  06
4.8
7.0
152.960
2062.6
04.93
0.51
140.50
25.50
168.80
9425
STT 288
14  53.4
+15  42
6.9
7.6
313.000
2137
01.36
0.50
108.50
49.00
12.50
9494
44,i Boo
15  03.8
+47  39
5.2
var.
214.800
2012.0
03.70
0.51
83.70
39.10
56.70
9617
Eta CrB
15  23.2
+30  17
5.6
6.0
41.630
1975.55
00.862
0.279
58.08
39.88
202.83
9626
Mu2 Boo
15  24.5
+37  23
7.1
7.6
256.500
2120.8
01.45
0.58
134.20
338.70
176.20
Gamma Lup
15  35.1
–41  10
3.5
3.6
190.000
2075.0
00.655
0.51
95.00
311.50
94.60
9909
Xi Sco AB
16  04.4
–11  22
5.2
4.9
45.900
1997.22
00.654
0.744
34.50
163.80
25.30
9979
Sigma CrB
16  14.7
+33  52
5.6
6.5
657.000
1828
05.0
0.77
23.20
76.80
1.00
10087
Lambda Oph
16  30.9
+01  59
4.2
5.2
129.000
2068.5
00.90
0.615
23.80
148.80
61.20
10157
Zeta Her
16  41.3
+31  36
3.0
5.4
34.460
2002.28
01.33
0.463
131.60
113.20
50.60
10279
20 Dra
16  56.4
+65  02
7.1
7.3
321.300
2077
01.1
0.24
96.20
112.10
67.40
10345
Mu Dra
17  05.3
+54  28
5.7
5.7
424.000
1938.8
03.0
0.22
146.60
31.40
128.80
MlbO 4 AB
17  19.0
–34  59
6.4
7.4
42.190
2018.16
01.80
0.57
127.60
68.340
133.50
10660
26 Dra
17  35.0
+61  52
5.3
8.5
76.100
2023.1
01.53
0.18
104.00
307.00
151.00
11005
Tau Oph
18  03.1
–08  11
5.3
5.9
2570..0.
2086
01.40
0.77
52.00
42.00
60.00
11046
70 Oph
18  05.5
+02  30
4.2
6.2
88.400
1984.22
04.550
0.498
120.90
193.40
121.70
HJ 5014
18  06.8
–43  25
5.7
5.7
450.000
2304.7
02.04
0.65
123.10
282.70
85.80
11483
STT 358
18  35.9
+16  59
6.9
7.1
513.000
2277
01.7
0.43
129.80
78.70
38.50
11635
Epsilon1 Lyr AB
18  44.3
+39  40
5.0
6.1
10780.00
2074
04.2
0.77
114.90
267.60
155.30
11635
Epsilon2 Lyr CD
18  44.4
+39  37
5.3
5.4
10760.00
2129
04.7
0.63
113.70
55.50
43.40
Gamma CrA
19  06.4
–37  04
4.5
6.4
122.200
2000.0
01.88
0.32
147.90
345.90
48.70
12880
Delta Cyg
19  45.0
+45  08
2.9
6.3
6570.00
1866
02.7
0.44
154.30
151.10
138.50
14296
Lambda Cyg
20  47.4
+36  29
4.7
6.3
8000.00
1837
01.0
0.44
144.70
300.90
67.90
14360
4 Aqr
20  51.4
–05  38
6.4
7.4
200.700
2097.5
00.816
0.535
64.06
45.90
174.31
14499
Epsilon Equ AB
20  59.1
+04  18
6.0
6.3
104.000
2024.75
00.609
0.692
92.40
343.30
105.30
14636
61 Cyg
21  06.9
+38  45
5.4
6.1
619.000
2318
25.2
0.54
56.30
313.90
1.30
14787
Tau Cyg
21  14.8
+38  03
3.8
6.6
49.5200
1988.47
00.92
0.245
133.20
116.40
161.30
15270
Mu Cyg
21  44.1
+28  45
4.8
6.2
692.000
1958.2
04.6
0.62
75.20
143.20
111.00
15971
Zeta Aqr
22  28.8
–00  01
4.3
4.5
427.000
1987
03.2
0.30
142.00
284.90
138.00
16538
Pi Cep
23  07.9
+75  23
4.6
6.8
176.000
1932.6
00.89
0.66
41.80
108.20
68.00
16836
72 Peg
23  34.0
+31  20
5.7
6.1
492.310
1904.92
00.568
0.32
21.70
293.00
56.20

Orbital elements from the Sixth Catalog of Orbits of Visual Binary Stars by Rachel A. Matson, Stephen J. Williams, William I. Hartkopf, and Brian D. Mason

Page last updated 2020 May.

An earlier version of this table appeared in Norton’s Star Atlas (Ian Ridpath, ed.)