18181-1215 DBK 1 Aa,Ab

Coord 2000	18181-1215		Discov num	DBK   1		Comp	Aa,Ab		Coord arcsec 2000	18 18 05.90 -12 14 33.3
Date first	2008		Date last	2019		Obs	16
Pa first	107		Pa last	261.6		P.A. Now (θ)	261.6°
Sep first	0.0		Sep last	0.02		Sep. Now (ρ)	0.02"
Mag pri	5.80		Mag sec	6.00		delta mag (ΔM)	0.2		Spectral class	O8Ia (blue)
Pri motion ra	-000		Sec motion ra
Pri motion dec	-003		Sec motion dec
Notes	N K (See Notes, K-band or other infrared magnitudes)

Visually invisible, K-band or other infrared star : Summary line gives K-band or other infrared (>1 micron) magnitudes Nature of this double is uncertain.

Show	name	SAO	coord	wds_name	last	obs	pa	sep	mag1	mag2	d_mag	orb	current
Show		161292	18 18 06 -12 14 33	DBK 1 Aa,Ab	2019	16	262	0.0	5.80	6.00	0.20	Y	<===
Show		161292	18 18 06 -12 14 33	TRN 27 AB	2012	3	40	4.8	7.45	16.00	8.55
Show		161292	18 18 06 -12 14 33	SS 7 AC	2015	6	191	14.4	7.45	14.30	6.85
Show		161292	18 18 06 -12 14 33	SS 7 AD	2015	9	260	18.1	7.45	12.90	5.45
Show		161292	18 18 06 -12 14 33	SS 7 AE	2015	9	217	18.1	7.45	13.00	5.55
Show	MY Ser	161292	18 18 06 -12 14 33	SS 7 AF	2018	14	16	30.1	7.45	10.80	3.35
Show		161292	18 18 06 -12 14 33	SS 7 AG	2015	7	9	39.4	7.45	15.50	8.05
Show		161292	18 18 06 -12 14 33	SS 7 AH	2018	12	268	40.8	7.45	9.80	2.35
Show		161292	18 18 06 -12 14 33	SS 7 AI	2015	5	299	45.7	7.45	13.70	6.25
Show		161292	18 18 06 -12 14 33	SS 7 AJ	2015	7	258	45.4	7.45	11.42	3.97
Show		161292	18 18 06 -12 14 33	SS 7 AK	2015	6	262	48.6	7.45	10.51	3.06
Show		161292	18 18 06 -12 14 33	SS 7 AL	2015	7	348	51.8	7.45	14.50	7.05
Show		161292	18 18 06 -12 14 33	SS 7 AM	2015	7	255	64.4	7.45	15.30	7.85
Show		161292	18 18 06 -12 14 33	SS 7 AN	2015	7	280	71.3	7.45	15.10	7.65
Show		161292	18 18 06 -12 14 33	SS 7 AO	2015	7	305	72.1	7.45	15.90	8.45
Show		161292	18 18 06 -12 14 33	SS 7 AP	2018	11	285	72.5	7.45	10.40	2.95
Show		161292	18 18 06 -12 14 33	SS 7 AQ	2015	9	291	84.9	7.45	11.70	4.25
Show			18 18 03 -12 14 40	BRT 2749 KJ	2015	8	121	4.3	10.51	11.42	0.91

18-fold system
17 estimated visually detectable stars in this system

Var name	MY Ser		Constellation	Serpens		SAO	161292		HIP	89681
Tycho2	5685-04419-1		Gaia DR2	4153657378750644864		HD	167971		BD	BD-12 4980
Distance	662.25		Distance ly	2160.26

Period (P)	7895d (21.62y)	± 520	Periastron (T)	54696d (2008.628y)	± 50	Semi-major axis (a)	18.6m	± 1.1
Eccentricity (e)	0.479	± 0.031	Inclination (i)	145.4°	± 4.1	Longitude of periastron (ω)	118.4°	± 6.8
Node (Ω)	213°	± 11	Notes	n		Reference	LeB2017
Equinox			Last observation			Grade	5	(1=Definitive, 9=Indet.)

label theta rho 2000 254.2 0.024 2001 247.1 0.024 2002 239.7 0.023 2003 231.7 0.022 2004 222.6 0.021 2005 211.6 0.018 2006 196.7 0.015 2007 173.0 0.011 2008 128.2 0.008 2009 69.4 0.009 2010 30.9 0.012 2011 6.2 0.014 2012 347.4 0.016 2013 332.2 0.017 2014 319.2 0.019 2015 307.9 0.020 2016 297.9 0.021 2017 288.9 0.022 2018 280.6 0.023 2019 272.9 0.024 2020 265.6 0.024 2021 258.5 0.024 2022 251.5 0.024 2023 244.3 0.024 2024 236.7 0.023 2025 228.4 0.022 2026 218.7 0.020 2027 206.5 0.017 2028 189.1 0.014 2029 159.1 0.010 2030 104.6 0.008		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic