18368-2617 RST 3187 AB (HD 171595)

Coord 2000	18368-2617		Discov num	RST3187		Comp	AB		Coord arcsec 2000	18 36 48.23 -26 17 21.6
Date first	1934		Date last	2021		Obs	24
Pa first	231		Pa last	201.4		P.A. Now (θ)	209.7°
Sep first	0.2		Sep last	0.132		Sep. Now (ρ)	0.18"
Mag pri	8.47		Mag sec	8.96		delta mag (ΔM)	0.49		Spectral class	G3V (yellow)
Pri motion ra	-043		Sec motion ra
Pri motion dec	-040		Sec motion dec
Notes	O (Orbital solution)

This double is physical.

Show	name	SAO	coord	wds_name	last	obs	pa	sep	mag1	mag2	d_mag	orb	current
Show	HD 171595	187041	18 36 48 -26 17 22	RST 3187 AB	2021	24	201	0.1	8.47	8.96	0.49	Y	<===
Show		187041	18 36 48 -26 17 22	RST 3187 AC	2015	9	41	12.7	8.47	13.80	5.33

Triple system
3 estimated visually detectable stars in this system

Name	HD 171595		Constellation	Sagittarius		SAO	187041		HIP	91253
Tycho2	6866-00039-1		Gaia DR2	4075912835700087424		HD	171595		CD	CD-2613320
CP	CP-26 6518		Distance	46.43		Distance ly	151.45

Period (P)	18.37y	± 0.18	Periastron (T)	2017.3y	± 0.16	Semi-major axis (a)	0.1661a	± 0.002
Eccentricity (e)	0.364	± 0.022	Inclination (i)	70.1°	± 0.8	Longitude of periastron (ω)	7.2°	± 2.9
Node (Ω)	40.6°	± 0.9	Notes			Reference	Tok2016e
Equinox	2000		Last observation			Grade	3	(1=Definitive, 9=Indet.)

label theta rho 2000 64.8 0.076 2001 118.1 0.047 2002 177.0 0.073 2003 196.9 0.118 2004 205.9 0.159 2005 211.5 0.191 2006 215.7 0.212 2007 219.3 0.224 2008 222.7 0.225 2009 226.1 0.217 2010 230.1 0.200 2011 234.9 0.174 2012 242.0 0.139 2013 254.3 0.099 2014 283.6 0.061 2015 343.7 0.055 2016 20.6 0.086 2017 38.5 0.106 2018 55.5 0.090 2019 91.9 0.053 2020 161.8 0.058 2021 191.7 0.102 2022 203.2 0.145 2023 209.7 0.180 2024 214.3 0.205 2025 218.0 0.221 2026 221.4 0.226 2027 224.8 0.222 2028 228.5 0.208 2029 233.0 0.185 2030 239.0 0.153		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic