09101-5129 RST 381 (Tau UMa)

Coord 2000	09101-5129		Discov num	RST 381		Comp			Coord arcsec 2000	09 10 08.42 -51 28 46.5
Date first	1929		Date last	2016		Obs	6
Pa first	174		Pa last	173.9		P.A. Now (θ)	173.9°
Sep first	2.4		Sep last	2.616		Sep. Now (ρ)	2.616"
Mag pri	11.21		Mag sec	11.57		delta mag (ΔM)	0.36		Spectral class	A3 (white)
Pri motion ra	-008		Sec motion ra	-003
Pri motion dec	+041		Sec motion dec	-023
Notes

rPM=1.537 This double is not physical.

Name	Tau UMa		Constellation	Vela		SAO	14796		HIP	45075
Tycho2	8177-01806-1		Gaia DR2	5323989478140437888		HD	78362		HR	3624
GC	12646		ADS	7211		BD	BD+64 723		Bayer	Tau Ursae Majoris
Bayer name	Tau UMa		FK5	2727		Distance	38.73		Distance ly	126.34
Bayer greek	τ UMa

Bayer or Flamsteed indentifiers not always match the correct constellation because of procession and proper motion of the star. (UMa vs Vel)

Period (P)	1062.4d (2.91y)		Periastron (T)	25721.6d (1929.299y)		Semi-major axis (a)	3.6m	± 0.2
Eccentricity (e)	0.48		Inclination (i)	87.3°	± 3.4	Longitude of periastron (ω)	349.4°
Node (Ω)	296.5°	± 1.9	Notes	n		Reference	Ren2013
Equinox	2000		Last observation			Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 114.2 0.004 2001-01-01 117.1 0.005 2002-01-01 295.6 0.002 2003-01-01 114.6 0.004 2004-01-01 117.3 0.005 2005-01-01 297.4 0.002 2006-01-01 114.9 0.004 2007-01-01 117.7 0.004 2008-01-01 299.5 0.001 2009-01-01 115.2 0.005 2010-01-01 118.0 0.004 2011-01-01 304.1 0.001 2012-01-01 115.5 0.005 2013-01-01 118.5 0.003 2014-01-01 342.3 2015-01-01 115.7 0.005 2016-01-01 119.2 0.003 2017-01-01 102.0 0.001 2018-01-01 116.0 0.005 2019-01-01 120.3 0.002 2020-01-01 109.4 0.001 2021-01-01 116.2 0.005 2022-01-01 122.7 0.001 2023-01-01 111.7 0.002 2024-01-01 116.4 0.005 2025-01-01 134.5 2026-01-01 112.9 0.003 2027-01-01 116.6 0.005 2028-01-01 284.0 2029-01-01 113.7 0.003 2030-01-01 116.8 0.005		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic

Period (P)	635.4d		Periastron (T)	45464.5d (1983.353y)		Semi-major axis (a)	2.9m	± 0.4
Eccentricity (e)	0.149		Inclination (i)	141.6°	± 17.1	Longitude of periastron (ω)	135.4°
Node (Ω)	288.7°	± 8.7	Notes	n		Reference	Ren2013
Equinox	2000		Last observation			Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 309.5 0.003 2001-01-01 91.0 0.003 2002-01-01 274.3 0.003 2003-01-01 35.7 0.002 2004-01-01 219.1 0.002 2005-01-01 342.3 0.003 2006-01-01 138.1 0.002 2007-01-01 304.0 0.003 2008-01-01 82.7 0.003 2009-01-01 267.8 0.003 2010-01-01 26.4 0.002 2011-01-01 206.1 0.002 2012-01-01 335.4 0.003 2013-01-01 128.1 0.002 2014-01-01 298.6 0.003 2015-01-01 74.3 0.003 2016-01-01 260.7 0.003 2017-01-01 17.3 0.002 2018-01-01 192.4 0.002 2019-01-01 328.9 0.003 2020-01-01 118.8 0.002 2021-01-01 293.2 0.003 2022-01-01 65.7 0.003 2023-01-01 252.8 0.003 2024-01-01 8.4 0.003 2025-01-01 178.5 0.002 2026-01-01 322.7 0.003 2027-01-01 110.1 0.003 2028-01-01 287.7 0.003 2029-01-01 56.8 0.002 2030-01-01 244.0 0.002		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic

Period (P)	273.4d		Periastron (T)	48373d (1991.317y)		Semi-major axis (a)	3.44m	± 1.5
Eccentricity (e)	0.177		Inclination (i)	109.1°	± 32.3	Longitude of periastron (ω)	99.7°	± 30.6
Node (Ω)	338.1°	± 21.3	Notes			Reference	Pbx2000a
Equinox			Last observation	1993		Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 2.7 0.003 2001-01-01 300.9 0.001 2002-01-01 144.4 0.003 2003-01-01 1.1 0.003 2004-01-01 295.3 0.001 2005-01-01 143.2 0.003 2006-01-01 359.6 0.003 2007-01-01 288.4 0.001 2008-01-01 141.9 0.003 2009-01-01 358.1 0.003 2010-01-01 280.1 0.001 2011-01-01 140.6 0.003 2012-01-01 356.8 0.003 2013-01-01 270.1 0.001 2014-01-01 139.2 0.003 2015-01-01 355.5 0.003 2016-01-01 258.7 0.001 2017-01-01 137.7 0.003 2018-01-01 354.3 0.003 2019-01-01 246.5 0.001 2020-01-01 136.1 0.003 2021-01-01 353.2 0.003 2022-01-01 234.3 0.001 2023-01-01 134.4 0.002 2024-01-01 352.1 0.003 2025-01-01 223.2 0.001 2026-01-01 132.7 0.002 2027-01-01 351.0 0.003 2028-01-01 213.5 0.001 2029-01-01 130.7 0.002 2030-01-01 350.0 0.003		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic

Period (P)	566d	± 28	Periastron (T)	48815d (1992.527y)	± 88	Semi-major axis (a)	11m	± 10
Eccentricity (e)	0.78	± 0.23	Inclination (i)	84°	± 6	Longitude of periastron (ω)	79°	± 96
Node (Ω)	328°	± 92	Notes			Reference	Gln2006
Equinox			Last observation	1993		Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 310.5 0.004 2001-01-01 171.8 0.005 2002-01-01 152.5 0.008 2003-01-01 297.7 0.003 2004-01-01 165.9 0.006 2005-01-01 149.0 0.006 2006-01-01 270.9 0.002 2007-01-01 161.8 0.007 2008-01-01 330.1 0.003 2009-01-01 224.4 0.002 2010-01-01 158.8 0.008 2011-01-01 321.3 0.005 2012-01-01 191.6 0.003 2013-01-01 156.3 0.009 2014-01-01 314.8 0.005 2015-01-01 176.6 0.004 2016-01-01 153.9 0.009 2017-01-01 305.5 0.004 2018-01-01 168.7 0.006 2019-01-01 151.2 0.007 2020-01-01 287.9 0.003 2021-01-01 163.8 0.007 2022-01-01 144.4 0.003 2023-01-01 250.3 0.002 2024-01-01 160.3 0.008 2025-01-01 324.8 0.005 2026-01-01 206.0 0.002 2027-01-01 157.6 0.008 2028-01-01 318.5 0.005 2029-01-01 183.2 0.003 2030-01-01 155.2 0.009		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic

Period (P)	584d	± 54	Periastron (T)	48785d (1992.445y)	± 234	Semi-major axis (a)	12m	± 12
Eccentricity (e)	0.73	± 0.28	Inclination (i)	92°	± 6	Longitude of periastron (ω)	82°	± 96
Node (Ω)	326°	± 92	Notes			Reference	Gln2006
Equinox			Last observation	1993		Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 334.9 0.004 2001-01-01 140.8 0.007 2002-01-01 325.4 0.004 2003-01-01 42.3 0.001 2004-01-01 143.1 0.009 2005-01-01 329.2 0.007 2006-01-01 134.6 0.004 2007-01-01 144.8 0.009 2008-01-01 334.6 0.004 2009-01-01 140.7 0.007 2010-01-01 325.2 0.004 2011-01-01 34.8 0.001 2012-01-01 143.0 0.009 2013-01-01 329.1 0.007 2014-01-01 134.3 0.004 2015-01-01 144.8 0.009 2016-01-01 334.4 0.004 2017-01-01 140.6 0.007 2018-01-01 324.9 0.003 2019-01-01 27.9 0.001 2020-01-01 143.0 0.009 2021-01-01 329.0 0.007 2022-01-01 134.0 0.003 2023-01-01 144.7 0.009 2024-01-01 334.2 0.004 2025-01-01 140.5 0.007 2026-01-01 324.4 0.003 2027-01-01 21.8 0.001 2028-01-01 142.9 0.009 2029-01-01 328.9 0.007 2030-01-01 133.6 0.003		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic

Period (P)	1546d (4.23y)	± 284	Periastron (T)	49135d (1993.403y)	± 626	Semi-major axis (a)	22.3m	± 7.8
Eccentricity (e)	0.67	± 0.22	Inclination (i)	117°	± 8	Longitude of periastron (ω)	101°	± 93
Node (Ω)	274°	± 92	Notes			Reference	Gln2007
Equinox			Last observation	1991		Grade	9	(1=Definitive, 9=Indet.)

label theta rho 2000-01-01 330.6 0.019 2001-01-01 298.0 0.021 2002-01-01 101.1 0.009 2003-01-01 32.8 0.016 2004-01-01 340.2 0.018 2005-01-01 305.1 0.022 2006-01-01 246.7 0.006 2007-01-01 46.2 0.016 2008-01-01 350.9 0.017 2009-01-01 312.2 0.021 2010-01-01 277.0 0.015 2011-01-01 59.5 0.016 2012-01-01 2.7 0.016 2013-01-01 319.8 0.021 2014-01-01 287.8 0.019 2015-01-01 73.4 0.015 2016-01-01 15.6 0.016 2017-01-01 328.0 0.020 2018-01-01 295.8 0.021 2019-01-01 91.9 0.011 2020-01-01 28.9 0.016 2021-01-01 337.2 0.018 2022-01-01 303.0 0.022 2023-01-01 200.5 0.004 2024-01-01 42.3 0.016 2025-01-01 347.6 0.017 2026-01-01 310.1 0.021 2027-01-01 272.2 0.013 2028-01-01 55.5 0.016 2029-01-01 359.1 0.017 2030-01-01 317.5 0.021		Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
		Measures: green=micrometric, blue=interferometric, purple=photographic