19549+5049 HU 687 (HD 188871)

 
 
19h 54m 56.19s +50° 49' 11.9" P.A. 27.00 sep 0.2 mag 8.54,8.63 Sp A0 dist. 256.41 pc (836.41 l.y.)
 
 
Coord 2000 19549+5049 Discov num HU  687 Comp Coord arcsec 2000 19 54 56.19 +50 49 11.9
Date first 1904 Date last 2008 Obs 45
Pa first 93 Pa last 26.9 P.A. Now (θ) 45°
Sep first 0.2 Sep last 0.196 Sep. Now (ρ) 0.201"
Mag pri 8.54 Mag sec 8.63 delta mag (ΔM) 0.09 Spectral class A0 (white)
Pri motion ra +005 Sec motion ra
Pri motion dec +025 Sec motion dec
Notes N O (See Notes, Orbital solution)
This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Name HD 188871 Constellation Cygnus SAO 32104 HIP 97997
Tycho2 3570-00245-1 Gaia DR2 2088834258965337216 HD 188871 ADS 13135
BD BD+50 2920 Distance 256.41 Distance ly 836.41
 
 
ORBITAL ELEMENTS
 
 
Period (P)154.6y Periastron (T)1960.63y Semi-major axis (a)0.159a
Eccentricity (e)0.321 Inclination (i)36.2° Longitude of periastron (ω)218.9°
Node (Ω)28.9° Notesn ReferenceDoc2017f
Equinox2000 Last observation2008 Grade3(1=Definitive, 9=Indet.)
label theta rho
2000 16.5 0.174
2001 18.0 0.176
2002 19.4 0.178
2003 20.8 0.180
2004 22.2 0.182
2005 23.6 0.184
2006 24.9 0.185
2007 26.2 0.187
2008 27.5 0.188
2009 28.7 0.190
2010 30.0 0.191
2011 31.2 0.192
2012 32.4 0.194
2013 33.6 0.195
2014 34.8 0.196
2015 35.9 0.197
2016 37.1 0.197
2017 38.2 0.198
2018 39.4 0.199
2019 40.5 0.199
2020 41.6 0.200
2021 42.8 0.200
2022 43.9 0.200
2023 45.0 0.201
2024 46.1 0.201
2025 47.3 0.201
2026 48.4 0.201
2027 49.5 0.201
2028 50.6 0.200
2029 51.7 0.200
2030 52.8 0.200


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



 
 


wds19549%2B5049b.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic