20123-0806 BU 1205

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.

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

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			Grade	4	(1=Definitive, 9=Indet.)
Equinox	2000		Last observation	2008

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.
		Measures: green=micrometric, blue=interferometric, purple=photographic

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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