21573+3241 A 1226 (HD 208687)

 
 
21h 57m 17.70s +32° 40' 32.4" P.A. 181.00 sep 0.1 mag 9.29,9.90 Sp A3 dist. 1063.83 pc (3470.21 l.y.)
 
 
Coord 2000 21573+3241 Discov num A  1226 Comp Coord arcsec 2000 21 57 17.70 +32 40 32.4
Date first 1905 Date last 2011 Obs 24
Pa first 349 Pa last 180.9 P.A. Now (θ) 180.9°
Sep first 0.3 Sep last 0.103 Sep. Now (ρ) 0.103"
Mag pri 9.29 Mag sec 9.90 delta mag (ΔM) 0.61 Spectral class A3 (white)
Pri motion ra -013 Sec motion ra
Pri motion dec +006 Sec motion dec
Notes O (Orbital solution)
This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Name HD 208687 Constellation Pegasus SAO 71873 HIP 108373
Tycho2 2723-01872-1 Gaia DR2 1899751450496790912 HD 208687 ADS 15487
BD BD+31 4589 Distance 1063.83 Distance ly 3470.21
 
 
ORBITAL ELEMENTS
 
 
Period (P)124.2y Periastron (T)1963.49y Semi-major axis (a)0.325a
Eccentricity (e)0.871 Inclination (i)105.6° Longitude of periastron (ω)281°
Node (Ω)116.5° Notes ReferenceSca2019b
Equinox2000 Last observation2017 Grade4(1=Definitive, 9=Indet.)
label theta rho
2000 27.6 0.145
2001 25.7 0.146
2002 23.8 0.148
2003 22.0 0.149
2004 20.2 0.151
2005 18.4 0.153
2006 16.7 0.155
2007 15.0 0.157
2008 13.4 0.159
2009 11.8 0.161
2010 10.3 0.163
2011 8.8 0.165
2012 7.3 0.167
2013 5.9 0.169
2014 4.5 0.171
2015 3.1 0.174
2016 1.8 0.176
2017 0.5 0.178
2018 359.2 0.180
2019 358.0 0.183
2020 356.8 0.185
2021 355.6 0.187
2022 354.5 0.190
2023 353.4 0.192
2024 352.3 0.194
2025 351.3 0.197
2026 350.2 0.199
2027 349.2 0.201
2028 348.2 0.204
2029 347.3 0.206
2030 346.3 0.208


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



 
 


wds21573%2B3241b.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic