20449+1219 STF 2723 AB (HD 197684)

20^h 44^m 54.58^s +12° 18' 45.6" P.A. 140.00 sep 1.0 mag 7.01,8.30 Sp A3IV dist. 209.21 pc (682.44 l.y.)

Coord 2000	20449+1219		Discov num	STF2723		Comp	AB		Coord arcsec 2000	20 44 54.58 +12 18 45.6
Date first	1831		Date last	2018		Obs	182
Pa first	86		Pa last	140.1		P.A. Now (θ)	140.1°
Sep first	1.5		Sep last	1.013		Sep. Now (ρ)	1.013"
Mag pri	7.01		Mag sec	8.30		delta mag (ΔM)	1.29		Spectral class	A3IV (white)
Pri motion ra	+020		Sec motion ra	+020
Pri motion dec	+003		Sec motion dec	+003
Notes	N O (See Notes, Orbital solution)

This double is physical.

20449+1219 SYSTEM COMPONENTS

Show	name	SAO	coord	wds_name	last	obs	pa	sep	mag1	mag2	d_mag	orb	current
Show		106443	20 44 55 +12 18 46	B 2910 Aa,Ab	2005	4	52	0.1	7.01
Show	HD 197684	106443	20 44 55 +12 18 46	STF 2723 AB	2018	182	140	1.0	7.01	8.30	1.29	Y	<===
Show		106443	20 44 55 +12 18 46	BU 1492 AC	2015	6	30	37.0	7.01	13.00	5.99

Quadruple system
3 estimated visually detectable stars in this system

OTHER CATALOGS AND DESIGNATIONS

Name	HD 197684		Constellation	Delphinus		SAO	106443		HIP	102390
Tycho2	1097-02486-1		Gaia DR2	1754983736625945216		HD	197684		GC	28916
BD	BD+11 4368		Distance	209.21		Distance ly	682.44

ORBITAL ELEMENTS

Period (P)	782.191y	± 379.9865	Periastron (T)	1753.7062y	± 100.0687	Semi-major axis (a)	1.6534a	± 0.55203
Eccentricity (e)	0.47767	± 0.33628	Inclination (i)	65.736°	± 11.693	Longitude of periastron (ω)	282.687°	± 32.118
Node (Ω)	77.006°	± 24.529	Notes	n		Reference	Izm2019
Equinox			Last observation	2015		Grade	4	(1=Definitive, 9=Indet.)

label	theta	rho
2000	131.9	1.059
2001	132.3	1.057
2002	132.7	1.055
2003	133.1	1.052
2004	133.5	1.050
2005	133.9	1.048
2006	134.4	1.046
2007	134.8	1.043
2008	135.2	1.041
2009	135.6	1.039
2010	136.0	1.037
2011	136.5	1.035
2012	136.9	1.033
2013	137.3	1.031
2014	137.7	1.029
2015	138.2	1.027
2016	138.6	1.025
2017	139.0	1.023
2018	139.5	1.021
2019	139.9	1.019
2020	140.3	1.018
2021	140.8	1.016
2022	141.2	1.014
2023	141.7	1.012
2024	142.1	1.011
2025	142.6	1.009
2026	143.0	1.008
2027	143.4	1.006
2028	143.9	1.004
2029	144.3	1.003
2030	144.8	1.002

grafico orbita

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

wds20449%2B1219a.png orbit plot

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