20213+0250 HLD 158

Coord 2000	20213+0250		Discov num	HLD 158		Comp			Coord arcsec 2000	20 21 17.43 +02 50 21.9
Date first	1882		Date last	2017		Obs	68
Pa first	40		Pa last	42		P.A. Now (θ)	41°
Sep first	2.0		Sep last	1.2		Sep. Now (ρ)	1.23"
Mag pri	9.71		Mag sec	9.78		delta mag (ΔM)	0.07		Spectral class	G0 (yellow)
Pri motion ra	+064		Sec motion ra	+064
Pri motion dec	-019		Sec motion dec	-019
Notes	N O (See Notes, Orbital solution)

Visually invisible, K-band or other infrared star This double is physical.

Precise pa	42		Precise sep	1.204		Constellation	Aquila		HIP	100355
Tycho2	0500-00340-1		Gaia DR2	20259760128		HD	193651		ADS	13738
Distance	440.53		Distance ly	1437.01		last precise pa	42		last precise sep	1.204

Period (P)	232.4y		Periastron (T)	1961.16y		Semi-major axis (a)	0.858a
Eccentricity (e)	0.746		Inclination (i)	128.6°		Longitude of periastron (ω)	17.7°
Node (Ω)	218.3°		Note			Grade	3	(1=Definitive, 9=Indet.)
Equinox	2000		Last observation	2016

label rho theta 2000 0.966 48.9 2001 0.982 48.4 2002 0.998 47.9 2003 1.014 47.4 2004 1.029 47.0 2005 1.044 46.5 2006 1.059 46.1 2007 1.073 45.7 2008 1.087 45.3 2009 1.100 44.9 2010 1.114 44.5 2011 1.127 44.1 2012 1.139 43.7 2013 1.152 43.4 2014 1.164 43.0 2015 1.176 42.7 2016 1.187 42.3 2017 1.198 42.0 2018 1.209 41.7 2019 1.220 41.4 2020 1.230 41.0 2021 1.240 40.7 2022 1.250 40.4 2023 1.260 40.1 2024 1.269 39.8 2025 1.278 39.5 2026 1.287 39.2 2027 1.296 39.0 2028 1.304 38.7 2029 1.312 38.4 2030 1.320 38.1 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
20213+0250	HLD 158		2001	61	48	1.0	9.71	9.78	G0	NO	202117.43+025021.9
20213+0250	HLD 158		2006	62	45	1.1	9.71	9.78	G0	NO	202117.43+025021.9
20213+0250	HLD 158		2007	63	44	1.1	9.71	9.78	G0	NO	202117.43+025021.9
20213+0250	HLD 158		2015	64	144	0.2	9.71	9.78	G0	NO	202117.43+025021.9
20213+0250	HLD 158		2016	65	42	1.2	9.71	9.78	G0	NO	202117.43+025021.9
20213+0250	HLD 158		2017	68	42	1.2	9.71	9.78	G0	NO	202117.43+025021.9

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