10074-1943 BU 218 (HD 87840)

10^h 07^m 22.22^s -19° 42' 31.2" P.A. 146.00 sep 0.4 mag 8.16,8.21 Sp A2IV dist. 207.9 pc (678.17 l.y.)

Coord 2000	10074-1943		Discov num	BU 218		Comp			Coord arcsec 2000	10 07 22.22 -19 42 31.2
Date first	1875		Date last	2017		Obs	42
Pa first	123		Pa last	145.7		P.A. Now (θ)	145.7°
Sep first	1.0		Sep last	0.435		Sep. Now (ρ)	0.435"
Mag pri	8.16		Mag sec	8.21		delta mag (ΔM)	0.05		Spectral class	A2IV (white)
Pri motion ra	-034		Sec motion ra	-034
Pri motion dec	+018		Sec motion dec	+018
Notes	O (Orbital solution)

This double is physical.

OTHER CATALOGS AND DESIGNATIONS

Name	HD 87840		Constellation	Hydra		SAO	155744		HIP	49587
Tycho2	6054-00753-1		Gaia DR2	5667772644917800192		HD	87840		ADS	7647
BD	BD-19 2918		Distance	207.9		Distance ly	678.17

ORBITAL ELEMENTS

Period (P)	1449.2807y	± 724.0248	Periastron (T)	1785.9264y	± 253.8953	Semi-major axis (a)	2.69076a	± 1.80641
Eccentricity (e)	0.78317	± 0.1884	Inclination (i)	86.131°	± 9.298	Longitude of periastron (ω)	295.406°	± 38.833
Node (Ω)	116.563°	± 5.291	Notes			Reference	Izm2019
Equinox			Last observation	1998		Grade	5	(1=Definitive, 9=Indet.)

label	theta	rho
2000	140.8	0.483
2001	141.1	0.478
2002	141.5	0.474
2003	141.8	0.469
2004	142.2	0.465
2005	142.5	0.460
2006	142.9	0.456
2007	143.2	0.451
2008	143.6	0.447
2009	144.0	0.442
2010	144.4	0.438
2011	144.8	0.433
2012	145.2	0.429
2013	145.6	0.424
2014	146.0	0.420
2015	146.5	0.416
2016	146.9	0.411
2017	147.4	0.407
2018	147.8	0.403
2019	148.3	0.398
2020	148.8	0.394
2021	149.3	0.390
2022	149.8	0.386
2023	150.3	0.381
2024	150.8	0.377
2025	151.3	0.373
2026	151.9	0.369
2027	152.4	0.365
2028	153.0	0.361
2029	153.6	0.357
2030	154.2	0.353

grafico orbita

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

wds10074-1943a.png orbit plot

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