21243+3740 WSI 7 (HD 203940)
21h 24m 16.13s +37° 39' 44.2" P.A. 44.00 sep 0.1 mag 7.81, Sp G5 dist. 48.5 pc (158.21 l.y.)
Coord 2000 |
21243+3740 |
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Discov num |
WSI 7 |
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Comp |
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Coord arcsec 2000 |
21 24 16.13 +37 39 44.2 |
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Date first |
1999 |
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Date last |
2012 |
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Obs |
5 |
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Pa first |
55 |
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Pa last |
43.5 |
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P.A. Now (θ) |
43.5° |
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Sep first |
0.1 |
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Sep last |
0.116 |
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Sep. Now (ρ) |
0.116" |
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Mag pri |
7.81 |
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Mag sec |
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delta mag (ΔM) |
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Spectral class |
G5 (yellow) |
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Pri motion ra |
+145 |
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Sec motion ra |
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Pri motion dec |
+008 |
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Sec motion dec |
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Notes |
O
(Orbital solution) |
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This double is physical.
OTHER CATALOGS AND DESIGNATIONS
Name |
HD 203940 |
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Constellation |
Cygnus |
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SAO |
71288 |
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HIP |
105676 |
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Tycho2 |
3182-04068-1 |
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Gaia DR2 |
1964029072058622464 |
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HD |
203940 |
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BD |
BD+37 4295 |
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Distance |
48.5 |
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Distance ly |
158.21 |
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ORBITAL ELEMENTS
Period (P) | 17.8y | ± 1.9 |
Periastron (T) | 2014.6y | ± 1.3 |
Semi-major axis (a) | 0.167a | ± 0.015 |
Eccentricity (e) | 0.31 | ± 0.1 |
Inclination (i) | 122.1° | ± 4.8 |
Longitude of periastron (ω) | 285.6° | ± 7.4 |
Node (Ω) | 247.3° | ± 7.8 |
Notes | | |
Reference | RAO2015 | |
Equinox | 2000 | |
Last observation | 2012 | |
Grade | 4 | (1=Definitive, 9=Indet.) |
label |
theta |
rho |
2000 |
232.6 |
0.148 |
2001 |
219.3 |
0.143 |
2002 |
204.1 |
0.131 |
2003 |
185.6 |
0.119 |
2004 |
164.4 |
0.114 |
2005 |
143.0 |
0.118 |
2006 |
124.4 |
0.131 |
2007 |
109.6 |
0.147 |
2008 |
97.7 |
0.163 |
2009 |
87.6 |
0.174 |
2010 |
78.4 |
0.176 |
2011 |
68.9 |
0.167 |
2012 |
57.2 |
0.143 |
2013 |
38.2 |
0.103 |
2014 |
352.7 |
0.064 |
2015 |
288.1 |
0.081 |
2016 |
259.2 |
0.121 |
2017 |
243.2 |
0.144 |
2018 |
230.1 |
0.148 |
2019 |
216.5 |
0.140 |
2020 |
200.7 |
0.128 |
2021 |
181.6 |
0.117 |
2022 |
160.0 |
0.114 |
2023 |
139.0 |
0.120 |
2024 |
121.2 |
0.134 |
2025 |
107.0 |
0.150 |
2026 |
95.6 |
0.165 |
2027 |
85.8 |
0.175 |
2028 |
76.6 |
0.176 |
2029 |
66.8 |
0.164 |
2030 |
54.3 |
0.136 |
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Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
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Measures: green=micrometric, blue=interferometric, purple=photographic |
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