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 Discov num BU  640 Comp Coord arcsec 2000 18 20 49.23 +27 31 48.3
Date first 1878 Date last 2008 Obs 22
Pa first 350 Pa last 321.9 P.A. Now (θ) 321.9°
Sep first 2.4 Sep last 0.731 Sep. Now (ρ) 0.731"
Mag pri 7.00 Mag sec 12.00 delta mag (ΔM) 5 Spectral class G1V (yellow)
Pri motion ra +058 Sec motion ra
Pri motion dec +083 Sec motion dec
Notes N O (See Notes, Orbital solution)




This double is physical.



OTHER CATALOGS AND DESIGNATIONS

Name HD 168874 Constellation Hercules SAO 85952 HIP 89912
Tycho2 2101-00082-1 Gaia DR2 4586000675189058304 HD 168874 GC 25049
ADS 11275 BD BD+27 3003 Distance 28.55 Distance ly 93.13




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 Notesn ReferenceIzm2019
Equinox Last observation2008 Grade5(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


 
grafico orbita
Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.



 
 


wds18208%2B2732a.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic