Double Star Calculator - Orbit

Orbital Elements for I557

WDS:	I557	WDS ID/Discoverer
P:	136.200	Orbital period (years)
a:	0.622	Semi-major axis (arcseconds)
i:	85.9	Inclination (degrees)
Ω:	26.4	Longitude of ascending node (degrees)
T:	2034.000	Epoch of periastron passage (year)
e:	0.726	Eccentricity
ω:	248.4	Longitude of periastron (degrees)
Start-Year:	1956.9	Year
End-Year:	2093.1	Year
Epoch:	2026.5	Besselian Epoch

Further data from the WDS Sixth Catalog of Orbits for I557
Position:	160926.97-310311.2	Epoch-2000 right ascension and declination
WDS-ID:	16094-3103	WDS designation
Discoverer Code:	I557	Discover designation and components
ADS number:	.	Aitken Double Star catalog
HD number:	144926	HD catalog number
Hipparcos number:	.	Hipparcos catalog number
V1:	7.8	Magnitude of the primary
V2:	8.2	Magnitude of the secondary
Equinox:	2000	Equinox
Date:	2019	Date of last observation
Orbit grade:	4	Orbit grade, ranging from : 1 = Definitive 2 = Good 3 = Reliable 4 = Preliminary 5 = Indeterminate
Flags:		Flags
Ephemerides:		Ephemerides
Code:	Doc2024a	Reference

Double Star Orbit for I557

WDS 6th Orbit including measures of I557

-- 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 I557

Click to expand/collapse ephemeris:

Year       Sep[“]   PA[°]
---------------------------------------------
2026.50    0.290   203.59
--------------------------
1956.90    0.488    34.34
1957.90    0.479    34.56
1958.90    0.470    34.78
1959.90    0.461    35.01
1960.90    0.452    35.25
1961.90    0.442    35.50
1962.90    0.432    35.77
1963.90    0.422    36.04
1964.90    0.412    36.33
1965.90    0.402    36.64
1966.90    0.391    36.96
1967.90    0.380    37.29
1968.90    0.370    37.65
1969.90    0.359    38.03
1970.90    0.348    38.43
1971.90    0.337    38.86
1972.90    0.325    39.32
1973.90    0.314    39.81
1974.90    0.302    40.34
1975.90    0.291    40.92
1976.90    0.279    41.54
1977.90    0.267    42.21
1978.90    0.255    42.95
1979.90    0.243    43.76
1980.90    0.231    44.65
1981.90    0.219    45.64
1982.90    0.207    46.75
1983.90    0.195    47.99
1984.90    0.183    49.40
1985.90    0.171    51.00
1986.90    0.159    52.85
1987.90    0.147    55.00
1988.90    0.135    57.52
1989.90    0.124    60.52
1990.90    0.113    64.11
1991.90    0.102    68.46
1992.90    0.092    73.80
1993.90    0.083    80.36
1994.90    0.076    88.38
1995.90    0.069    98.01
1996.90    0.066   109.08
1997.90    0.065   121.00
1998.90    0.066   132.82
1999.90    0.071   143.65
2000.90    0.077   152.96
2001.90    0.085   160.69
2002.90    0.094   166.99
2003.90    0.104   172.13
2004.90    0.115   176.33
2005.90    0.126   179.81
2006.90    0.137   182.72
2007.90    0.149   185.19
2008.90    0.160   187.30
2009.90    0.172   189.13
2010.90    0.183   190.73
2011.90    0.194   192.14
2012.90    0.206   193.40
2013.90    0.217   194.53
2014.90    0.227   195.55
2015.90    0.237   196.48
2016.90    0.247   197.34
2017.90    0.256   198.13
2018.90    0.265   198.87
2019.90    0.272   199.57
2020.90    0.279   200.23
2021.90    0.285   200.86
2022.90    0.289   201.47
2023.90    0.292   202.06
2024.90    0.293   202.65
2025.90    0.292   203.24
2026.90    0.287   203.83
2027.90    0.279   204.46
2028.90    0.266   205.13
2029.90    0.247   205.90
2030.90    0.219   206.82
2031.90    0.181   208.07
2032.90    0.131   210.15
2033.90    0.070   215.51
2034.90    0.013   293.12
2035.90    0.069    15.78
2036.90    0.133    21.17
2037.90    0.190    23.14
2038.90    0.241    24.23
2039.90    0.286    24.96
2040.90    0.325    25.50
2041.90    0.360    25.93
2042.90    0.391    26.29
2043.90    0.419    26.59
2044.90    0.444    26.86
2045.90    0.466    27.11
2046.90    0.486    27.33
2047.90    0.504    27.53
2048.90    0.520    27.72
2049.90    0.535    27.90
2050.90    0.548    28.08
2051.90    0.560    28.24
2052.90    0.570    28.40
2053.90    0.580    28.55
2054.90    0.588    28.70
2055.90    0.595    28.84
2056.90    0.602    28.98
2057.90    0.607    29.12
2058.90    0.612    29.25
2059.90    0.616    29.39
2060.90    0.619    29.52
2061.90    0.622    29.65
2062.90    0.624    29.78
2063.90    0.625    29.91
2064.90    0.626    30.04
2065.90    0.626    30.16
2066.90    0.626    30.29
2067.90    0.625    30.42
2068.90    0.624    30.55
2069.90    0.623    30.68
2070.90    0.620    30.81
2071.90    0.618    30.94
2072.90    0.615    31.07
2073.90    0.612    31.21
2074.90    0.608    31.34
2075.90    0.604    31.48
2076.90    0.600    31.62
2077.90    0.595    31.76
2078.90    0.590    31.90
2079.90    0.584    32.05
2080.90    0.579    32.20
2081.90    0.573    32.35
2082.90    0.566    32.50
2083.90    0.560    32.66
2084.90    0.553    32.82
2085.90    0.546    32.99
2086.90    0.539    33.16
2087.90    0.531    33.34
2088.90    0.523    33.52
2089.90    0.515    33.70
2090.90    0.507    33.90
2091.90    0.499    34.09
2092.90    0.490    34.30

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 17:23:33