18208+2732 BU 640 (HD 168874)
18h 20m 49.23s +27° 31' 48.3" P.A. 322.00 sep 0.7 mag 7.00,12.00 Sp G1V dist. 28.55 pc (93.13 l.y.)
Coord 2000 |
18208+2732 |
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Discov num |
BU 640 |
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Comp |
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Coord arcsec 2000 |
18 20 49.23 +27 31 48.3 |
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Date first |
1878 |
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Date last |
2008 |
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Obs |
22 |
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Pa first |
350 |
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Pa last |
321.9 |
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P.A. Now (θ) |
321.9° |
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Sep first |
2.4 |
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Sep last |
0.731 |
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Sep. Now (ρ) |
0.731" |
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Mag pri |
7.00 |
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Mag sec |
12.00 |
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delta mag (ΔM) |
5 |
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Spectral class |
G1V (yellow) |
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Pri motion ra |
+058 |
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Sec motion ra |
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Pri motion dec |
+083 |
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Sec motion dec |
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Notes |
N
O
(See Notes, Orbital solution) |
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This double is physical.
OTHER CATALOGS AND DESIGNATIONS
Name |
HD 168874 |
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Constellation |
Hercules |
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SAO |
85952 |
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HIP |
89912 |
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Tycho2 |
2101-00082-1 |
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Gaia DR2 |
4586000675189058304 |
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HD |
168874 |
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GC |
25049 |
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ADS |
11275 |
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BD |
BD+27 3003 |
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Distance |
28.55 |
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Distance ly |
93.13 |
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ORBITAL ELEMENTS
Period (P) | 951.7127y | ± 459.9382 |
Periastron (T) | 2021.803y | ± 39.5523 |
Semi-major axis (a) | 3.41354a | ± 1.49324 |
Eccentricity (e) | 0.94085 | ± 0.24975 |
Inclination (i) | 119.866° | ± 17.74 |
Longitude of periastron (ω) | 273.272° | ± 34.019 |
Node (Ω) | 101.88° | ± 56.48 |
Notes | n | |
Reference | Izm2019 | |
Equinox | | |
Last observation | 2008 | |
Grade | 5 | (1=Definitive, 9=Indet.) |
label |
theta |
rho |
2000 |
308.1 |
1.030 |
2001 |
307.4 |
1.006 |
2002 |
306.6 |
0.981 |
2003 |
305.8 |
0.955 |
2004 |
305.0 |
0.929 |
2005 |
304.1 |
0.902 |
2006 |
303.1 |
0.873 |
2007 |
302.1 |
0.844 |
2008 |
301.0 |
0.813 |
2009 |
299.9 |
0.781 |
2010 |
298.6 |
0.747 |
2011 |
297.2 |
0.712 |
2012 |
295.7 |
0.674 |
2013 |
293.9 |
0.634 |
2014 |
291.9 |
0.591 |
2015 |
289.6 |
0.544 |
2016 |
286.9 |
0.494 |
2017 |
283.4 |
0.437 |
2018 |
278.9 |
0.373 |
2019 |
272.3 |
0.301 |
2020 |
261.0 |
0.218 |
2021 |
235.0 |
0.132 |
2022 |
171.5 |
0.106 |
2023 |
129.5 |
0.178 |
2024 |
113.6 |
0.262 |
2025 |
105.2 |
0.336 |
2026 |
99.7 |
0.399 |
2027 |
95.6 |
0.454 |
2028 |
92.3 |
0.502 |
2029 |
89.6 |
0.546 |
2030 |
87.3 |
0.586 |
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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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