03363-1728 HDS 456 (20 Eri)

03^h 36^m 17.39^s -17° 28' 01.3" P.A. 100.00 sep 0.1 mag 5.48,6.84 Sp B8/B9III dist. 149.25 pc (486.85 l.y.)

Coord 2000	03363-1728		Discov num	HDS 456		Comp			Coord arcsec 2000	03 36 17.39 -17 28 01.3
Date first	1991		Date last	2020		Obs	20
Pa first	65		Pa last	99.5		P.A. Now (θ)	92.6°
Sep first	0.2		Sep last	0.113		Sep. Now (ρ)	0.158"
Mag pri	5.48		Mag sec	6.84		delta mag (ΔM)	1.36		Spectral class	B8/B9III (blue-white)
Pri motion ra	+033		Sec motion ra
Pri motion dec	-010		Sec motion dec
Notes	O (Orbital solution)

This double is physical.

OTHER CATALOGS AND DESIGNATIONS

Name	20 Eri		Var name	EG Eri		Constellation	Eridanus		SAO	149063
HIP	16803		Tycho2	5874-01098-1		Gaia DR2	5108493960822714752		HD	22470
HR	1100		GC	4305		BD	BD-17 699		Flamsteed	20 Eridani
Flamsteed name	20 Eri		FK5	1100		Distance	149.25		Distance ly	486.85

ORBITAL ELEMENTS

Period (P)	21y	± 0.27	Periastron (T)	2018.05y	± 0.08	Semi-major axis (a)	0.107a	± 0.003
Eccentricity (e)	0.841	± 0.008	Inclination (i)	134.3°	± 2.4	Longitude of periastron (ω)	197.9°	± 8.2
Node (Ω)	92.8°	± 5.9	Notes			Reference	Tok2019c
Equinox			Last observation	2018		Grade	3	(1=Definitive, 9=Indet.)

label	theta	rho
2000	100.3	0.119
2001	95.9	0.141
2002	92.6	0.158
2003	89.8	0.171
2004	87.4	0.181
2005	85.3	0.187
2006	83.2	0.191
2007	81.2	0.193
2008	79.2	0.191
2009	77.1	0.187
2010	74.9	0.181
2011	72.6	0.172
2012	69.9	0.160
2013	66.7	0.145
2014	62.7	0.127
2015	57.2	0.105
2016	48.2	0.078
2017	27.4	0.045
2018	272.9	0.017
2019	122.7	0.051
2020	107.1	0.090
2021	100.3	0.119
2022	95.9	0.141
2023	92.6	0.158
2024	89.8	0.171
2025	87.4	0.181
2026	85.3	0.187
2027	83.2	0.191
2028	81.2	0.193
2029	79.2	0.191
2030	77.1	0.187

grafico orbita

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

wds03363-1728a.png orbit plot

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