Sixth Catalog of Orbits of Visual Binary Stars — Web Search Interface
Results: 4051 rows (page 13)
Move the mouse over the image file to zoom in on the orbit or click on it for details and ephemerides.
| WDS designation |
Discover designation |
ADS number |
HD number |
Hipparcos number |
RA (2000) |
DEC (2000) |
image file |
orbit grade |
equinox |
last observation |
notes |
reference |
mag 1 (V) |
flag mag 1 |
mag 2 (V) |
flag mag 2 |
period |
P units |
P error |
semi-major axis |
a units |
a error |
inclination |
i error |
node (Omega) |
flag node |
node error |
time of periastron |
T0 units |
T0 error |
eccentricity |
e error |
longitude of periastron (omega) |
omega error |
|
03284+6015
|
A 980AB |
2538 |
21203 |
16177 |
032823.56 |
+601520.60 |
|
4 |
1950 |
1988 |
|
Baz1994
|
6.73 |
|
8.29 |
|
231.0 |
y |
|
0.38 |
a |
|
133.4 |
|
147.7 |
|
|
1961.0 |
y |
|
0.18 |
|
68.0 |
|
|
03286-3034
|
NLTT 11035 |
|
|
16192 |
032836.00 |
-303403.10 |
|
9 |
|
1991 |
|
Gln2007
|
11.5 |
|
|
|
695. |
d |
25. |
13.3 |
m |
2.8 |
56. |
9. |
140. |
|
98. |
48753. |
d |
182. |
0.08 |
0.24 |
82. |
73. |
|
03294-2406
|
GAA 18 |
|
21703 |
16247 |
032922.88 |
-240603.10 |
|
3 |
2000 |
2021 |
yes
|
GaA2023
|
6.4 |
k |
8.3 |
k |
3.980994 |
d |
0.00000 |
1.738 |
m |
0.003 |
86.9 |
0.1 |
190.0 |
|
0.1 |
51904. |
d |
1. |
0.0002 |
0.0002 |
170. |
107. |
|
03305+2006
|
RAO 11Ba,Bb |
|
21663 |
16329 |
033031.22 |
+200555.20 |
|
5 |
|
2018 |
|
Tok2019c
|
10.2 |
|
11. |
|
31.46 |
y |
0.25 |
0.294 |
a |
0.024 |
103.1 |
1.6 |
63.0 |
|
4.4 |
2015.18 |
y |
0.37 |
0.395 |
0.019 |
18.8 |
5.4 |
|
03307-1926
|
HDS 441 |
|
21841 |
16348 |
033040.06 |
-192608.00 |
|
3 |
2000 |
2014 |
|
Cve2016b
|
8.22 |
|
8.47 |
|
18.964 |
y |
0.125 |
0.2181 |
a |
0.0097 |
102.7 |
1.1 |
17.8 |
|
0.9 |
2007.281 |
y |
0.149 |
0.500 |
0.059 |
84.4 |
9.8 |
|
03309-6200
|
TOK 190 |
|
22166 |
16370 |
033052.51 |
-620028.50 |
|
2 |
|
|
yes
|
Tok2024c
|
7.0 |
|
8.5 |
|
3.627 |
y |
0.011 |
0.0637 |
a |
0.0011 |
79.2 |
0.8 |
30.4 |
|
0.8 |
2021.081 |
y |
0.027 |
0.445 |
0.023 |
242.5 |
1.8 |
|
03309+1256
|
5 Tau |
|
21754 |
16369 |
033052.37 |
+125612.10 |
|
9 |
|
1991 |
yes
|
HIP1997d
|
4.14 |
|
|
|
960.0000 |
d |
|
4.25 |
m |
1.51 |
36.95 |
29.53 |
207.61 |
|
37.37 |
47546.5703 |
d |
79.6215 |
0.3970 |
|
326.32 |
|
|
03310+2937
|
A 983 |
2578 |
21674 |
16376 |
033059.31 |
+293649.30 |
|
4 |
2000 |
2007 |
|
Doc2010d
|
9.64 |
|
10.2 |
|
587. |
y |
|
0.748 |
a |
|
63.2 |
|
150.8 |
|
|
1964.83 |
y |
|
0.591 |
|
245.3 |
|
|
03311-0029
|
HDS 444 |
|
21822 |
16389 |
033103.99 |
-002852.10 |
|
3 |
|
|
|
Msn2023
|
7.06 |
|
7.99 |
|
20.41 |
y |
0.90 |
0.0783 |
a |
0.0020 |
37.1 |
3.1 |
49.6 |
|
7.6 |
2025.02 |
y |
0.21 |
0.581 |
0.038 |
338. |
11. |
|
03321+4340
|
COU1688AB |
|
21727 |
16467 |
033205.10 |
+434011.50 |
|
4 |
2000 |
1986 |
yes
|
Baz1993d
|
8.56 |
|
8.9 |
|
9.15 |
y |
|
0.144 |
a |
|
43.7 |
|
26.5 |
|
|
1987.02 |
y |
|
0.08 |
|
303.9 |
|
|
03337+5752
|
CHR 117 |
|
21794 |
16602 |
033341.23 |
+575207.10 |
|
2 |
|
1998 |
yes
|
Bag2002
|
6.36 |
|
6.6 |
|
14.47 |
y |
0.07 |
0.120 |
a |
0.001 |
46. |
1. |
235. |
|
1. |
1990.15 |
y |
0.03 |
0.35 |
0.01 |
236. |
1. |
|
03339-3105
|
B 52 |
|
22262 |
16628 |
033356.81 |
-310449.10 |
|
2 |
2000 |
2021 |
yes
|
Tok2021c
|
6.69 |
|
7.63 |
|
19.408 |
y |
0.045 |
0.222 |
a |
0.001 |
85.1 |
0.2 |
140.9 |
|
0.2 |
2016.226 |
y |
0.076 |
0.355 |
0.002 |
3.4 |
1.6 |
|
03342+4837
|
BU 787AB |
2609 |
21931 |
16649 |
033412.97 |
+483702.90 |
|
5 |
|
2015 |
yes
|
Izm2019
|
7.38 |
|
11.9 |
|
1789.0608 |
y |
794.890 |
13.6229 |
a |
7.90366 |
76.999 |
8.893 |
153.189 |
|
25.712 |
1762.5670 |
y |
326.822 |
0.83271 |
0.12449 |
314.554 |
62.796 |
|
03344+2428
|
STF 412AB |
2616 |
22091 |
16664 |
033426.62 |
+242752.10 |
|
3 |
2000 |
2000 |
yes
|
Sca2002a
|
6.60 |
|
6.86 |
|
522.16 |
y |
|
0.625 |
a |
|
157.2 |
|
13.0 |
|
|
1911.62 |
y |
|
0.679 |
|
238.1 |
|
|
03350+6002
|
STF 400AB |
2612 |
21903 |
16712 |
033501.04 |
+600229.00 |
|
3 |
2000 |
2015 |
yes
|
Rbr2018
|
6.79 |
|
7.97 |
|
267.1 |
y |
7.7 |
1.112 |
a |
0.010 |
68.1 |
1.1 |
82.7 |
|
0.87 |
1939.07 |
y |
0.74 |
0.697 |
0.016 |
34.6 |
2.0 |
|
03356+3141
|
BU 533AB |
2628 |
22195 |
16757 |
033537.81 |
+314048.70 |
|
4 |
2000 |
2012 |
|
Zir2015a
|
7.55 |
|
7.74 |
|
463. |
y |
|
0.992 |
a |
|
94.8 |
|
42.7 |
|
|
1776.6 |
y |
|
0.110 |
|
15.3 |
|
|
03362+4220
|
A 1535 |
2630 |
22193 |
16793 |
033609.47 |
+422021.90 |
|
3 |
2000 |
2003 |
yes
|
Hrt2008
|
8.84 |
|
9.54 |
|
145.05 |
y |
8.72 |
0.531 |
a |
0.010 |
48.1 |
4.0 |
156.8 |
|
3.6 |
1940.32 |
y |
2.85 |
0.372 |
0.034 |
8.5 |
11.7 |
|
03363-1728
|
HDS 456 |
|
22470 |
16803 |
033617.39 |
-172801.30 |
|
3 |
|
2018 |
|
Tok2019c
|
5.48 |
|
6.84 |
|
21.00 |
y |
0.27 |
0.107 |
a |
0.003 |
134.3 |
2.4 |
92.8 |
|
5.9 |
2018.05 |
y |
0.08 |
0.841 |
0.008 |
197.9 |
8.2 |
|
03365+1011
|
A 830 |
2639 |
22376 |
16830 |
033630.85 |
+101107.70 |
|
5 |
2000 |
2003 |
|
Zir2012b
|
9.94 |
|
10.3 |
|
219.0 |
y |
|
0.325 |
a |
|
125.7 |
|
18.0 |
|
|
2066.2 |
y |
|
0.31 |
|
167.1 |
|
|
03368+0035
|
STF 422 |
2644 |
22468 |
16846 |
033647.30 |
+003515.90 |
|
4 |
|
2015 |
yes
|
Izm2019
|
6.00 |
|
8.90 |
|
1210.1296 |
y |
529.354 |
9.91243 |
a |
3.51866 |
62.963 |
13.17 |
28.852 |
|
15.800 |
1729.4709 |
y |
41.7282 |
0.72790 |
0.20802 |
103.033 |
10.640 |
|
03369-4957
|
SEE 29A |
|
22705 |
16853 |
033653.32 |
-495728.90 |
|
9 |
|
1993 |
yes
|
Mkr2007a
|
7.62 |
|
|
|
201. |
d |
2. |
5.1 |
m |
0.7 |
80. |
7. |
36. |
|
7. |
48400. |
d |
|
0.0 |
0.3 |
65. |
|
|
03375+3107
|
GC 4314 |
|
22418 |
16900 |
033728.02 |
+310712.60 |
|
9 |
|
1991 |
yes
|
HIP1997d
|
7.01 |
|
|
|
717.1133 |
d |
43.0233 |
8.79 |
m |
0.97 |
135.11 |
15.65 |
14.25 |
|
26.19 |
48169.8750 |
d |
52.0617 |
0.0000 |
|
0.00 |
|
|
03376+2121
|
PAT 1 |
|
|
16908 |
033734.98 |
+212035.40 |
|
5 |
|
|
|
Hor2021b
|
9.5 |
|
11.9 |
|
110.0 |
y |
1.4 |
0.8475 |
a |
0.0081 |
111.61 |
0.32 |
292.0 |
|
1.1 |
2071.06 |
y |
0.60 |
0.434 |
0.016 |
251.66 |
0.71 |
|
03379+0538
|
YSC 27 |
|
22556 |
16390 |
033752.46 |
+053828.70 |
|
3 |
|
|
|
Tok2020e
|
8.0 |
|
9.5 |
|
16.51 |
y |
0.2 |
0.1399 |
a |
0.0015 |
123.5 |
0.7 |
98.6 |
|
1.1 |
2013.02 |
y |
0.06 |
0.222 |
0.012 |
94.7 |
1.7 |
|
03390+4232
|
NLTT 11456 |
|
22521 |
17022 |
033857.34 |
+423219.00 |
|
9 |
|
1991 |
|
Gln2007
|
6.74 |
|
|
|
1093. |
d |
82. |
12.8 |
m |
3.4 |
66. |
7. |
252. |
|
98. |
48699. |
d |
202. |
0.49 |
0.25 |
140. |
128. |
|
03391+5249
|
YSC 127AB |
|
22451 |
17033 |
033906.47 |
+524908.80 |
|
3 |
|
|
|
Hor2020
|
8.5 |
|
8.6 |
|
2401.1 |
d |
3.2 |
42.0 |
m |
2.2 |
111.29 |
0.93 |
3.20 |
|
0.82 |
58281.9 |
d |
1.5 |
0.5804 |
0.0030 |
109.51 |
0.33 |
|
03396+1823
|
JAO 9Ba,Bb |
|
22694 |
17076 |
033932.95 |
+182301.70 |
|
2 |
2000 |
2014 |
yes
|
Jao2016
|
11.0 |
k |
|
|
0.826 |
y |
0.003 |
0.0225 |
a |
0.0008 |
128.31 |
4.98 |
123.12 |
|
3.42 |
1991.4394 |
y |
0.0008 |
0.577 |
0.004 |
253.24 |
0.46 |
|
03400+6352
|
HU 1062BC |
2650 |
. |
17126 |
034005.38 |
+635228.40 |
|
3 |
2000 |
|
yes
|
Tok2019e
|
6.92 |
|
8.27 |
|
11.42 |
y |
0.08 |
0.146 |
a |
0.002 |
70.0 |
|
52.4 |
q |
1.1 |
2000.601 |
y |
0.055 |
0.475 |
0.016 |
337.8 |
2.9 |
|
03401+3407
|
RBR 26Aa,Ab |
2668 |
22692 |
17129 |
034007.24 |
+340659.30 |
|
9 |
2000 |
2013 |
|
GnR2015a
|
7.52 |
|
|
|
106.5 |
y |
1.7 |
0.179 |
a |
0.008 |
106.8 |
2.4 |
65.5 |
|
2.6 |
1980.19 |
y |
0.94 |
0.612 |
0.050 |
77.8 |
3.4 |
|
03401+3407
|
STF 425AB |
2668 |
22692 |
17129 |
034007.24 |
+340659.30 |
|
4 |
|
2018 |
|
Kiy2018a
|
7.52 |
|
7.60 |
|
947. |
y |
149. |
2.930 |
a |
0.318 |
114.3 |
2.4 |
131.0 |
|
5.3 |
1456. |
y |
120. |
0.41 |
0.08 |
246. |
12. |
|
03402-1936
|
GC 4392 |
|
22921 |
17138 |
034012.48 |
-193534.30 |
|
9 |
|
1991 |
yes
|
HIP1997d
|
6.93 |
|
|
|
706.5027 |
d |
100.571 |
3.51 |
m |
0.80 |
137.99 |
20.32 |
115.86 |
|
22.84 |
48563.8750 |
d |
52.3959 |
0.0000 |
|
0.00 |
|
|
03407+0643
|
A 1934 |
2683 |
22888 |
|
034043.64 |
+064301.80 |
|
3 |
2000 |
2024 |
yes
|
Tok2024e
|
8.8 |
|
10.2 |
|
86.2 |
y |
3.3 |
0.321 |
a |
0.021 |
57.6 |
4.3 |
65.6 |
|
7.8 |
1947.83 |
y |
2.16 |
0.692 |
0.067 |
42.2 |
8.1 |
|
03413+4554
|
BU 1181AB |
2680 |
22743 |
17217 |
034115.89 |
+455345.00 |
|
3 |
2000 |
2012 |
yes
|
RAO2015
|
8.20 |
|
9.90 |
|
46.2 |
y |
1.1 |
0.27 |
a |
0.13 |
90.3 |
3.6 |
269.9 |
|
4.5 |
1974.8 |
y |
1.7 |
0.79 |
0.76 |
50.1 |
9.0 |
|
03417-5126
|
FR 9 |
|
23295 |
17255 |
034144.41 |
-512532.50 |
|
4 |
|
|
|
Tok2024c
|
9.2 |
|
9.7 |
|
2.791 |
y |
|
0.0709 |
a |
|
49.1 |
|
65.7 |
|
|
2021.688 |
y |
|
0.170 |
|
124.8 |
|
|
03422+6313
|
BD Cam |
|
22649 |
17296 |
034209.35 |
+631300.30 |
|
9 |
|
1993 |
yes
|
Pbx2000a
|
5.12 |
|
|
|
596.2 |
d |
|
2.30 |
m |
0.6 |
105.6 |
18.7 |
162.1 |
|
20.1 |
42794.5 |
d |
|
0.088 |
|
334.3 |
19.0 |
|
03423+3141
|
COU 691 |
|
|
|
034215.91 |
+314034.50 |
|
3 |
2000 |
2007 |
yes
|
Doc2010d
|
9.0 |
|
9.0 |
|
55.88 |
y |
|
0.155 |
a |
|
66.2 |
|
66.5 |
|
|
1961.93 |
y |
|
0.141 |
|
258.2 |
|
|
03425+1216
|
JNN 26 |
|
|
|
034231.82 |
+121622.40 |
|
5 |
|
|
yes
|
Bwl2020
|
14.7 |
|
19.9 |
|
470. |
y |
240. |
1.1062 |
a |
0.4243 |
80.8 |
4.7 |
12.9 |
|
5.0 |
2240.4286 |
y |
312.09 |
0.34 |
0.34 |
116. |
64. |
|
03426+1718
|
GC 4435 |
|
23052 |
17336 |
034236.96 |
+171736.30 |
|
9 |
|
1991 |
yes
|
HIP1997d
|
7.09 |
|
|
|
1000.6828 |
d |
29.5905 |
32.12 |
m |
1.49 |
78.27 |
1.55 |
79.50 |
|
1.86 |
48024.4023 |
d |
10.0292 |
0.0000 |
|
0.00 |
|
|
03434-0934
|
GJ 3247 |
|
|
|
034322.04 |
-093351.20 |
|
9 |
|
|
|
TSN2020
|
14.5 |
|
|
|
5.23 |
y |
0.02 |
23.70 |
m |
0.68 |
143.95 |
4.39 |
111.99 |
|
6.57 |
1995.82 |
y |
0.13 |
0.27 |
0.05 |
14.90 |
12.53 |
|
03440+5228
|
A 1289 |
2710 |
23006 |
17427 |
034400.54 |
+522807.80 |
|
5 |
2000 |
1995 |
|
USN2002
|
10.0 |
|
10.3 |
|
265. |
y |
|
0.32 |
a |
|
51.5 |
|
147.4 |
|
|
2080. |
y |
|
0.633 |
|
75.7 |
|
|
03442-6448
|
TOK 191Aa,Ab |
|
23817 |
17440 |
034411.98 |
-644824.80 |
|
9 |
|
1991 |
yes
|
HIP1997d
|
4.0 |
|
6.8 |
|
1911.5000 |
d |
|
27.10 |
m |
2.50 |
82.85 |
3.36 |
22.39 |
|
6.82 |
48872.4805 |
d |
18.5393 |
0.2100 |
|
13.80 |
|
|
03447+2755
|
STT4038B |
|
23257 |
17482 |
034444.90 |
+275517.30 |
|
9 |
|
1991 |
|
Gln2007
|
6.77 |
|
|
|
699. |
d |
28. |
13.2 |
m |
2.5 |
132. |
10. |
205. |
|
94. |
48535. |
d |
228. |
0.27 |
0.22 |
100. |
96. |
|
03448+4602
|
BAG 8AB |
|
23140 |
17491 |
034448.83 |
+460209.00 |
|
2 |
|
2016 |
yes
|
MnA2019
|
7.90 |
|
10.6 |
|
13.604 |
y |
0.046 |
254.9 |
m |
1.3 |
101.79 |
0.38 |
100.68 |
|
0.46 |
58570. |
d |
24. |
0.268 |
0.011 |
250.5 |
1.3 |
|
03453+2428
|
Pleiades H 156 |
|
23338 |
17531 |
034512.49 |
+242802.10 |
|
9 |
2000 |
1994 |
|
Ole2003b
|
4.6 |
|
6.1 |
|
2.02 |
y |
|
0.055 |
a |
|
83.6 |
|
84.6 |
|
|
1989.92 |
y |
|
0.456 |
|
225.5 |
|
|
03454-2752
|
BU 1003 |
2756 |
23588 |
17544 |
034524.12 |
-275144.90 |
|
5 |
2000 |
2001 |
yes
|
Cve2008a
|
8.39 |
|
11.1 |
|
286.34 |
y |
4.83 |
2.145 |
a |
0.092 |
34.7 |
4.0 |
81.7 |
|
3.6 |
1997.42 |
y |
3.95 |
0.479 |
0.107 |
101.7 |
9.8 |
|
03462-2423
|
RST2321 |
|
23686 |
17600 |
034613.16 |
-242327.70 |
|
3 |
|
|
|
Tok2020e
|
9.37 |
|
9.72 |
|
96.26 |
y |
2.43 |
0.215 |
a |
0.0034 |
43.9 |
4.6 |
11.5 |
|
9.6 |
2013.99 |
y |
0.4 |
0.832 |
0.027 |
155.8 |
0.9 |
|
03463-6630
|
HDS 477 |
|
24136 |
17604 |
034615.64 |
-663014.50 |
|
4 |
2000 |
2017 |
|
Tok2017c
|
8.40 |
|
8.62 |
|
59.5 |
y |
|
0.159 |
a |
|
38.5 |
|
127.1 |
|
|
2012.96 |
y |
|
0.867 |
|
67.7 |
|
|
03463+2411
|
BU 536AB |
2755 |
23479 |
|
034616.00 |
+241123.50 |
|
4 |
|
2008 |
yes
|
Hrt2009
|
8.13 |
|
9.39 |
|
885.64 |
y |
385.32 |
1.211 |
a |
0.124 |
99.3 |
2.3 |
175.3 |
|
0.7 |
1877.90 |
y |
73.36 |
0.314 |
0.002 |
245.5 |
62.5 |
|
03466+2255
|
RDR 2AB |
|
23514 |
|
034638.39 |
+225511.20 |
|
5 |
|
|
yes
|
Bwl2020
|
9.43 |
|
16. |
|
7010. |
y |
900. |
3.0066 |
a |
1.1536 |
140. |
17. |
259. |
|
100. |
7207.3986 |
y |
635.90 |
0.29 |
0.28 |
106. |
74. |
|
03470+4126
|
STF 443AB |
|
|
|
034702.11 |
+412538.10 |
|
4 |
|
2015 |
yes
|
Izm2019
|
8.20 |
|
8.82 |
|
2275.5193 |
y |
904.618 |
22.7850 |
a |
10.3129 |
85.419 |
2.650 |
37.681 |
|
2.120 |
1636.1743 |
y |
65.3539 |
0.82609 |
0.13286 |
282.781 |
13.368 |
Description of Columns
RA (2000) : epoch-2000 right ascension (hours, minutes, seconds)
DEC (2000) : epoch-2000 declination (degrees, minutes, seconds)
WDS designation : based on arcminute-accuracy epoch-2000 coordinates)
Discover designation : Discover designation and components, or other catalog designation
ADS number : ADS (Aitken Double Star catalog) number
HD number : HD catalog number
Hipparcos number : Hipparcos catalog number
mag 1 (V) : Magnitude of the primary (usually V)
flag mag 1 : flag:
> = fainter than quoted magnitude
< = brighter than quoted magnitude
v = variable magnitude
k = magnitude is in K-band or other infrared band
? = magnitude is uncertain
mag 2 (V) : Magnitude of the secondary (usually V)
flag mag 2 : flag:
> = fainter than quoted magnitude
< = brighter than quoted magnitude
v = variable magnitude
k = magnitude is in K-band or other infrared band
? = magnitude is uncertain
period : Period (P)
P units : Code for units:
m = minutes (not yet used!)
h = hours (not yet used!)
d = days
y = years
c = centuries (rarely used)
P error : Published formal error in P (in same units as for P)
semi-major axis : Semi-major axis (a)
a units : Code for units:
a = arcseconds
m = milliarcseconds (mas)
M = arcminutes (used only for alp Cen + Proxima Cen)
u = microarcseconds (uas - not yet used)
a error : Error in a. Units are the same as for a
inclination : Inclination (i), in degrees
i error : Error in i
node (Omega) : Node (Omega), in degrees. An identified ascending node is indicated by
an asterisk following the value.
flag node : If the ascending node is later determined to off by 180deg, it is flipped,
and a "q" code added to indicate the change.
node error : Error in Omega
time of periastron : The time of periastron passage (T0)
T0 units : Code for units:
c = centuries (fractional year / 100; used only for alp Cen + Proxima Cen)
d = truncated Julian date (JD-2,400,000 days)
m = modified Julian date (MJD = JD-2,400,000.5 days)
y = fractional Besselian year
T0 error : Error in T0. Units are the same as for T0
eccentricity : Eccentricity (e)
e error : Error in e
longitude of periastron : Longitude of periastron (omega), in degrees, reckoned
(omega) from the node as listed. If the published omega value
is later determined to fall in the wrong quadrant, the
value is flipped by 180deg; a letter "q" indicates the
quadrant has been corrected.
omega error : Error in omega
equinox : Equinox, if any, to which the node refers
last observation : Date of the last observation used in the orbit calculation, if published.
orbit grade : Orbit grade, ranging from 1 ("definitive") to 5
("indeterminate"). Additionally, a grade of 8 is used
for interferometric orbits based on visibilities
rather than rho and theta measures (hence not gradable
by the present scheme) and a grade of 9 indicates an
astrometric binary (also lacking rho and theta data).
notes : A clickable flag "yes" to any notes for this system.
reference : A clickable code for the reference (usually based on the name of
the first author and the date of publication).
The bibcode in the references file is clickable and links to ADS.
image file : Name of image file (png format) illustrating orbit and
all associated measures in the Washington Double Star
database.
The data presented here comes from the USNO website (updated: April 2026)