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 Discov num WSI   7 Comp Coord arcsec 2000 21 24 16.13 +37 39 44.2
Date first 1999 Date last 2012 Obs 5
Pa first 55 Pa last 43.5 P.A. Now (θ) 43.5°
Sep first 0.1 Sep last 0.116 Sep. Now (ρ) 0.116"
Mag pri 7.81 Mag sec delta mag (ΔM) Spectral class G5 (yellow)
Pri motion ra +145 Sec motion ra
Pri motion dec +008 Sec motion dec
Notes O (Orbital solution)
This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Name HD 203940 Constellation Cygnus SAO 71288 HIP 105676
Tycho2 3182-04068-1 Gaia DR2 1964029072058622464 HD 203940 BD BD+37 4295
Distance 48.5 Distance ly 158.21
 
 
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 ReferenceRAO2015
Equinox2000 Last observation2012 Grade4(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


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



 
 


wds21243%2B3740a.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic