Double Star Calculator - Orbit

Orbital Elements for HDS2989DA,DB

WDS:	HDS2989DA,DB	WDS ID/Discoverer
P:	212.700	Orbital period (years)
a:	0.94	Semi-major axis (arcseconds)
i:	90.9	Inclination (degrees)
Ω:	154.5	Longitude of ascending node (degrees)
T:	2142.300	Epoch of periastron passage (year)
e:	0.85	Eccentricity
ω:	270.0	Longitude of periastron (degrees)
Start-Year:	1918.65	Year
End-Year:	2131.35	Year
Epoch:	2026.5	Besselian Epoch

Further data from the WDS Sixth Catalog of Orbits for HDS2989DA,DB
Position:	205811.46+401129.0	Epoch-2000 right ascension and declination
WDS-ID:	20599+4016	WDS designation
Discoverer Code:	HDS2989DA,DB	Discover designation and components
ADS number:	.	Aitken Double Star catalog
HD number:	.	HD catalog number
Hipparcos number:	103502	Hipparcos catalog number
V1:	11.16	Magnitude of the primary
V2:	12.46	Magnitude of the secondary
Equinox:	2000	Equinox
Date:	2018	Date of last observation
Orbit grade:	4	Orbit grade, ranging from : 1 = Definitive 2 = Good 3 = Reliable 4 = Preliminary 5 = Indeterminate
Flags:	n	Flags
Ephemerides:		Ephemerides
Code:	Tok2019e	Reference

Double Star Orbit for HDS2989DA,DB

WDS 6th Orbit including measures of HDS2989DA,DB

-- Image from the USNO WDS 6th Orbit Catalog (see Acknowledgements) --

Legend:

Green plus signs:	Visual (micrometric) measures
Violet asterisks:	Photographic measures
Blue symbols:	Various interferometric techniques
Dot-dash line:	Indicates the line of nodes

Ephemeris of HDS2989DA,DB

Click to expand/collapse ephemeris:

Year       Sep[“]   PA[°]
---------------------------------------------
2026.50    0.079   134.50
--------------------------
1918.65    0.434   335.22
1919.65    0.421   335.15
1920.65    0.406   335.08
1921.65    0.388   335.00
1922.65    0.367   334.91
1923.65    0.342   334.82
1924.65    0.312   334.70
1925.65    0.275   334.56
1926.65    0.228   334.36
1927.65    0.168   334.04
1928.65    0.089   333.24
1929.65    0.005   178.92
1930.65    0.098   155.62
1931.65    0.174   154.92
1932.65    0.233   154.62
1933.65    0.279   154.43
1934.65    0.315   154.29
1935.65    0.345   154.17
1936.65    0.370   154.08
1937.65    0.390   153.99
1938.65    0.408   153.91
1939.65    0.423   153.84
1940.65    0.435   153.78
1941.65    0.446   153.71
1942.65    0.455   153.65
1943.65    0.463   153.59
1944.65    0.470   153.54
1945.65    0.476   153.48
1946.65    0.481   153.43
1947.65    0.485   153.37
1948.65    0.488   153.32
1949.65    0.491   153.27
1950.65    0.493   153.22
1951.65    0.494   153.17
1952.65    0.495   153.12
1953.65    0.495   153.07
1954.65    0.495   153.02
1955.65    0.495   152.96
1956.65    0.494   152.91
1957.65    0.493   152.86
1958.65    0.491   152.81
1959.65    0.489   152.76
1960.65    0.487   152.71
1961.65    0.485   152.66
1962.65    0.482   152.60
1963.65    0.479   152.55
1964.65    0.476   152.50
1965.65    0.473   152.44
1966.65    0.469   152.39
1967.65    0.465   152.33
1968.65    0.461   152.27
1969.65    0.457   152.21
1970.65    0.453   152.15
1971.65    0.448   152.09
1972.65    0.444   152.03
1973.65    0.439   151.97
1974.65    0.434   151.90
1975.65    0.429   151.83
1976.65    0.424   151.77
1977.65    0.418   151.70
1978.65    0.413   151.62
1979.65    0.407   151.55
1980.65    0.402   151.48
1981.65    0.396   151.40
1982.65    0.390   151.32
1983.65    0.384   151.24
1984.65    0.378   151.15
1985.65    0.372   151.06
1986.65    0.366   150.97
1987.65    0.360   150.88
1988.65    0.353   150.78
1989.65    0.347   150.68
1990.65    0.340   150.57
1991.65    0.334   150.47
1992.65    0.327   150.35
1993.65    0.320   150.23
1994.65    0.314   150.11
1995.65    0.307   149.98
1996.65    0.300   149.85
1997.65    0.293   149.71
1998.65    0.286   149.56
1999.65    0.279   149.40
2000.65    0.272   149.24
2001.65    0.265   149.07
2002.65    0.257   148.89
2003.65    0.250   148.69
2004.65    0.243   148.49
2005.65    0.236   148.27
2006.65    0.228   148.04
2007.65    0.221   147.80
2008.65    0.214   147.54
2009.65    0.206   147.26
2010.65    0.199   146.95
2011.65    0.191   146.63
2012.65    0.184   146.28
2013.65    0.176   145.89
2014.65    0.169   145.48
2015.65    0.161   145.02
2016.65    0.154   144.52
2017.65    0.146   143.97
2018.65    0.138   143.36
2019.65    0.131   142.68
2020.65    0.123   141.91
2021.65    0.116   141.04
2022.65    0.108   140.05
2023.65    0.101   138.92
2024.65    0.093   137.59
2025.65    0.086   136.04
2026.65    0.078   134.20
2027.65    0.071   131.97
2028.65    0.064   129.23
2029.65    0.057   125.81
2030.65    0.050   121.44
2031.65    0.044   115.75
2032.65    0.038   108.20
2033.65    0.033    98.16
2034.65    0.029    85.12
2035.65    0.027    69.46
2036.65    0.028    53.05
2037.65    0.030    38.30
2038.65    0.035    26.48
2039.65    0.040    17.52
2040.65    0.046    10.79
2041.65    0.053     5.68
2042.65    0.060     1.73
2043.65    0.067   358.61
2044.65    0.074   356.09
2045.65    0.081   354.02
2046.65    0.089   352.30
2047.65    0.096   350.85
2048.65    0.104   349.61
2049.65    0.111   348.54
2050.65    0.119   347.60
2051.65    0.126   346.77
2052.65    0.134   346.04
2053.65    0.141   345.39
2054.65    0.149   344.80
2055.65    0.157   344.27
2056.65    0.164   343.79
2057.65    0.172   343.35
2058.65    0.179   342.95
2059.65    0.187   342.58
2060.65    0.194   342.24
2061.65    0.202   341.92
2062.65    0.209   341.63
2063.65    0.217   341.36
2064.65    0.224   341.10
2065.65    0.231   340.86
2066.65    0.239   340.64
2067.65    0.246   340.43
2068.65    0.253   340.23
2069.65    0.260   340.04
2070.65    0.267   339.86
2071.65    0.275   339.69
2072.65    0.282   339.53
2073.65    0.289   339.38
2074.65    0.296   339.24
2075.65    0.303   339.10
2076.65    0.309   338.97
2077.65    0.316   338.84
2078.65    0.323   338.72
2079.65    0.330   338.60
2080.65    0.336   338.49
2081.65    0.343   338.38
2082.65    0.349   338.28
2083.65    0.356   338.18
2084.65    0.362   338.08
2085.65    0.368   337.99
2086.65    0.375   337.90
2087.65    0.381   337.82
2088.65    0.387   337.73
2089.65    0.393   337.65
2090.65    0.398   337.57
2091.65    0.404   337.49
2092.65    0.410   337.42
2093.65    0.415   337.35
2094.65    0.421   337.28
2095.65    0.426   337.21
2096.65    0.431   337.14
2097.65    0.436   337.07
2098.65    0.441   337.01
2099.65    0.446   336.95
2100.65    0.450   336.88
2101.65    0.455   336.82
2102.65    0.459   336.76
2103.65    0.463   336.71
2104.65    0.467   336.65
2105.65    0.471   336.59
2106.65    0.474   336.54
2107.65    0.477   336.48
2108.65    0.480   336.43
2109.65    0.483   336.38
2110.65    0.486   336.32
2111.65    0.488   336.27
2112.65    0.490   336.22
2113.65    0.492   336.17
2114.65    0.493   336.12
2115.65    0.494   336.07
2116.65    0.495   336.01
2117.65    0.495   335.96
2118.65    0.495   335.91
2119.65    0.495   335.86
2120.65    0.494   335.81
2121.65    0.492   335.76
2122.65    0.490   335.71
2123.65    0.487   335.66
2124.65    0.483   335.61
2125.65    0.479   335.55
2126.65    0.474   335.50
2127.65    0.468   335.44
2128.65    0.460   335.38
2129.65    0.452   335.33
2130.65    0.442   335.26

Disclaimer

This result is provided without warranty. For all terms, see the Full Disclaimer. Copyright (C) 2025. Unless otherwise noted, all output generated by the Double Star Calculator including orbit diagrams, ephemerides, and analytical reports is licensed under CC BY 4.0.

Acknowledgements

The Double Star Calculator - Orbital Elements makes use of the Washington Double Star Sixth Catalog of Orbits of Visual Binary Stars, maintained at the U.S. Naval Observatory.

Report Information

Double Star Calculator:		Version 1.2 ($Rev: 2397 $)
Report created:		2026-06-25 18:20:28