20123-0806 BU 1205

 
 
20h 12m 15.32s -08 05' 32.1" P.A. 42.70 sep 0.5 mag 7.50,8.80 Sp F5V dist. 73.91 pc (241.09 l.y.)
 
 
Coord 2000
20123-0806
Discov num
BU 1205
Comp
Coord arcsec 2000
20 12 15.32 -08 05 32.1
Date first
1890
Date last
2008
Obs
22
Pa first
49
Pa last
212
P.A. Now (θ)
42.7°
Sep first
0.6
Sep last
0.2
Sep. Now (ρ)
0.46"
Mag pri
7.50
Mag sec
8.80
delta mag (ΔM)
1.3
Spectral class
F5V (yellow-white)
Pri motion ra
+015
Sec motion ra
Pri motion dec
-035
Sec motion dec
Notes
O (Orbital solution)
Visually invisible, K-band or other infrared star This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Precise pa
211.8
Precise sep
0.247
Constellation
Aquila
HIP
99558
Tycho2
5740-00887-1
Gaia DR2
52139704960
HD
191841
ADS
13493
BD
BD-08 5272
Distance
73.91
Distance ly
241.09
last precise pa
211.8
last precise sep
0.247
 
 
ORBITAL ELEMENTS
 
 
Period (P)139.9y Periastron (T)1983.5y Semi-major axis (a)0.486a
Eccentricity (e)0.384 Inclination (i)78.3° Longitude of periastron (ω)10.4°
Node (Ω)231.24° Note Grade4(1=Definitive, 9=Indet.)
Equinox2000 Last observation2008
label rho theta
2000 0.086 341.4
2001 0.098 355.0
2002 0.115 5.1
2003 0.134 12.5
2004 0.154 18.1
2005 0.175 22.3
2006 0.196 25.7
2007 0.217 28.4
2008 0.238 30.6
2009 0.258 32.4
2010 0.279 34.0
2011 0.299 35.4
2012 0.318 36.6
2013 0.337 37.6
2014 0.356 38.6
2015 0.374 39.4
2016 0.392 40.2
2017 0.409 40.9
2018 0.426 41.6
2019 0.442 42.2
2020 0.457 42.7
2021 0.472 43.3
2022 0.486 43.7
2023 0.500 44.2
2024 0.514 44.7
2025 0.526 45.1
2026 0.538 45.5
2027 0.550 45.9
2028 0.561 46.2
2029 0.571 46.6
2030 0.581 46.9

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






wds20123-0806a.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic
 
 
 
WDS HISTORIC DATA
 
 
coord_2000 discov_num comp epoch obs pa sep mag_pri mag_sec spectr notes coord_arcsec_2000
20123-0806 BU 1205 1991 21 249 0.2 7.50 8.80 F5V O 201215.32-080532.1
20123-0806 BU 1205 2008 22 212 0.2 7.50 8.80 F5V O 201215.32-080532.1

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