Content-Type: text/html; charset=UTF-8 Double Star Calculator - Orbital Elements

Double Star Calculator - Orbit

- Revision:		$Rev: 1216 $
- Report created:		2025-07-11 19:29:06

Orbital Elements for BU989AB

WDS:	BU989AB	WDS ID/Discoverer
P:	11.567	Orbital period (years)
a:	0.23494	Semi-major axis (arcseconds)
i:	107.911	Inclination (degrees)
Ω:	289.037	Longitude of ascending node (degrees)
T:	2002.348	Epoch of periastron passage (year)
e:	0.314	Eccentricity
ω:	304.666	Longitude of periastron (degrees)
Start-Year:	2020.0	Year
End-Year:	2030.0	Year
Epoch:	2025.0	Besselian Epoch

Further data from the WDS Sixth Catalog of Orbits for BU989AB

Position:	214438.70+253842.0	Epoch-2000 right ascension and declination
WDS-ID:	21446+2539	WDS designation
Discoverer Code:	BU989AB	Discover designation and components
ADS number:	15281	Aitken Double Star catalog
HD number:	206901	HD catalog number
Hipparcos number:	107354	Hipparcos catalog number
V1:	4.94	Magnitude of the primary
V2:	5.04	Magnitude of the secondary
Equinox:	2000	Equinox
Date:	2007	Date of last observation
Orbit grade:	1	Orbit grade, ranging from 1 'definitive' to 5 'indeterminate'
Flags:	n	Flags

Double Star Orbit for BU989AB

WDS 6th Orbit including measures of BU989AB

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

Ephemeris of BU989AB

Click to expand/collapse ephemeris:

Year       Sep[“]   PA[°]
---------------------------------------------
2025.0     0.053      3.0
-------------------------
2020.0     0.210    129.3
2021.0     0.256    120.1
2022.0     0.269    113.0
2023.0     0.237    105.4
2024.0     0.148     91.8
2025.0     0.053      3.0
2026.0     0.155    296.7
2027.0     0.184    280.6
2028.0     0.141    262.1
2029.0     0.091    221.0

Disclaimer

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.