02543+5246 LAB 1 Aa,Ab

02^h 54^m 15.46^s +52° 45' 45.0" P.A. 277.00 sep 0.1 mag 4.20,5.90 Sp G8III+A7V dist. 77.94 pc (254.24 l.y.)

Coord 2000	02543+5246		Discov num	LAB 1		Comp	Aa,Ab		Coord arcsec 2000	02 54 15.46 +52 45 45.0
Date first	1973		Date last	2010		Obs	13
Pa first	274		Pa last	277.3		P.A. Now (θ)	278.7°
Sep first	0.1		Sep last	0.058		Sep. Now (ρ)	0.063"
Mag pri	4.20		Mag sec	5.90		delta mag (ΔM)	1.7		Spectral class	G8III+A7V (yellow/white)
Pri motion ra	-003		Sec motion ra
Pri motion dec	-005		Sec motion dec
Notes	N O (See Notes, Orbital solution)

This double is physical.

02543+5246 SYSTEM COMPONENTS

Show	name	SAO	coord	wds_name	last	obs	pa	sep	mag1	mag2	d_mag	orb	current
Show		23685	02 54 15 +52 45 45	LAB 1 Aa,Ab	2010	13	277	0.1	4.20	5.90	1.70	Y	<===
Show	Tau Per	23685	02 54 15 +52 45 45	EDG 1 AB	2015	9	107	51.0	3.95	12.28	8.33
Show		23685	02 54 15 +52 45 45	BU 1376 AC	2014	5	107	50.9	3.95	12.70	8.75
Show		23685	02 54 15 +52 45 45	BU 1376 AD	2015	4	338	41.9	3.95	11.50	7.55
Show			02 54 21 +52 45 30	BU 1376 BC	2009	7	86	4.2	12.28	12.70	0.42

Quintuple system
4 estimated visually detectable stars in this system

OTHER CATALOGS AND DESIGNATIONS

Constellation	Perseus		SAO	23685		HIP	13531		Tycho2	3701-01394-1
Gaia DR2	441161693272720640		HD	17879		HR	854		GC	3462
ADS	2202		BD	BD+52 641		Bayer	Tau Persei		Bayer name	Tau Per
Flamsteed	18 Persei		Flamsteed name	18 Per		FK5	103		Distance	77.94
Distance ly	254.24		Bayer greek	τ Per

ORBITAL ELEMENTS

Period (P)	4.149y		Periastron (T)	2013.888y		Semi-major axis (a)	0.055a
Eccentricity (e)	0.728		Inclination (i)	94.5°		Longitude of periastron (ω)	54.1°
Node (Ω)	100.6°		Notes	n		Reference	Doc2014f
Equinox	2000		Last observation	1994		Grade	3	(1=Definitive, 9=Indet.)

label	theta	rho
2000	270.0	0.035
2001	116.6	0.013
2002	279.7	0.054
2003	276.3	0.066
2004	271.5	0.041
2005	140.0	0.007
2006	280.6	0.045
2007	276.8	0.067
2008	272.6	0.046
2009	211.9	0.005
2010	282.0	0.032
2011	277.3	0.068
2012	273.5	0.051
2013	249.7	0.011
2014	287.0	0.012
2015	277.7	0.068
2016	274.2	0.055
2017	260.8	0.018
2018	98.5	0.014
2019	278.2	0.066
2020	274.9	0.059
2021	265.7	0.024
2022	104.4	0.021
2023	278.7	0.063
2024	275.5	0.062
2025	268.6	0.031
2026	110.0	0.017
2027	279.3	0.059
2028	276.0	0.065
2029	270.4	0.037
2030	120.7	0.011

grafico orbita

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

wds02543%2B5246a.png orbit plot

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