19490+1909 AGC  11AB (Zet Sge)

Coord 2000	19490+1909		Discov num	AGC  11		Comp	AB		Coord arcsec 2000	19 48 58.65 +19 08 31.1
Date first	1875		Date last	2010		Obs	261
Pa first	137		Pa last	174		P.A. Now (θ)	149.6°
Sep first	0.4		Sep last	0.2		Sep. Now (ρ)	0.19"
Mag pri	5.64		Mag sec	6.04		delta mag (ΔM)	0.4		Spectral class	A1V (white)
Pri motion ra	+019		Sec motion ra
Pri motion dec	+027		Sec motion dec
Notes	N O (See Notes, Orbital solution)

This double is physical.

Show	name	SAO	coord_2000	discov#	comp	first	last	obs	pa	sep	mag1	mag2	d_mag	orb	current
Show	Zet Sge	105298	19490+1909	AGC 11	AB	1875	2010	261	150	0.2	5.64	6.04	0.40	Y	<===
Show		105298	19490+1909	STF2585	AB,C	1819	2016	131	311	8.3	5.04	9.01	3.97
Show		105298	19490+1909	STF2585	AB,D	1895	2005	10	246	76.0	5.04	11.00	5.96

Quadruple system
5 visible stars in this system

Precise pa	174.3		Precise sep	0.23		Name	Zet Sge		Constellation	Sagitta
SAO	105298		HIP	97496		Tycho2	1623-02647-1		HD	187362
HR	7546		GC	27431		ADS	12973		BD	BD+18 4254
Bayer	Zeta Sagittae		Bayer name	Zet Sge		Flamsteed	8 Sagittae		Flamsteed name	8 Sge
Distance	78.19		Distance ly	255.06		last precise pa	174.3		last precise sep	0.23

Period (P)	8487.9d (23.24y)	± 4.9	Periastron (T)	44199.6m (1979.892y)	± 5.9	Semi-major axis (a)	0.13605a	± 0.00044
Eccentricity (e)	0.7948	± 0.0019	Inclination (i)	132.33°	± 0.41	Longitude of periastron (ω)	355.3°	± 1
Node (Ω)	340.97°	± 0.68	Note			Grade	1	(1=Definitive, 9=Indet.)
Equinox	2000		Last observation	2007

label rho theta 2000 0.133 139.5 2001 0.098 130.6 2002 0.056 109.6 2003 0.027 4.5 2004 0.042 237.9 2005 0.083 204.2 2006 0.118 192.3 2007 0.148 185.6 2008 0.172 181.0 2009 0.192 177.5 2010 0.209 174.6 2011 0.222 172.0 2012 0.232 169.8 2013 0.238 167.6 2014 0.243 165.6 2015 0.244 163.6 2016 0.242 161.7 2017 0.238 159.6 2018 0.231 157.5 2019 0.220 155.2 2020 0.206 152.6 2021 0.189 149.6 2022 0.167 145.9 2023 0.140 141.0 2024 0.107 133.3 2025 0.067 117.2 2026 0.027 44.0 2027 0.034 257.7 2028 0.073 208.8 2029 0.110 194.4 2030 0.141 186.9 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
19490+1909	AGC 11	AB	2001	243	117	0.1	5.64	6.04	A1V	NOD	194858.65+190831.1
19490+1909	AGC 11	AB	2004	246	28	0.1	5.64	6.04	A1V	NOD	194858.65+190831.1
19490+1909	AGC 11	AB	2007	248	184	0.2	5.64	6.04	A1V	NOD	194858.65+190831.1

If you need more information about this double, apply for a data request form to the WDS.