Altjira (148780 2001 UQ18)

System parameters

Heliocentric orbitPhotometry Position 2025/08/22 20:59 UTC
DES class = CLASSICAL HV = 6.32±0.07 +05:21:06.98 +28:12:08.8
<a> = 44.29 (AU) V = 23.0 (V2 = 23.8) Uncertainty = 0.4 (arcsec)
<e> = 0.059 Δmag = 0.23 Rates: +2.012, +0.372 ("/hr)
<i> = 5.47 (degrees) B-V = 0.9±0.1  
Perihelion = 2216 V-R = 0.74±0.08 Opposition: December
Aphelion = 2067    

Astrometric observations

Observation time (UTC)Observatory/InstrumentRADEC Δ (AU)Δx (arcsec) Δx errorΔy (arcsec) Δy error
2006/08/06  06.39990 HST/ACS-HRC +03:46:03.89 +24:18:30.7 45.62654 -0.17182 0.00109 +0.06302 0.00408
2007/07/25  01.93083 HST/WFPC2-PC +03:50:21.12 +24:33:38.4 45.88604 -0.16332 0.00167 -0.03667 0.00168
2007/08/07  22.34333 HST/WFPC2-PC +03:50:59.45 +24:36:56.3 45.67245 -0.27679 0.00204 -0.00742 0.00100
2007/10/06  21.50194 HST/WFPC2-PC +03:50:25.62 +24:41:31.3 44.73594 -0.05278 0.00100 +0.04552 0.00190
2007/11/12  09.23131 HST/WFPC2-PC +03:47:52.84 +24:36:01.2 44.44869 +0.14054 0.00138 -0.06317 0.00118
2008/07/25  07.16861 HST/WFPC2-PC +03:55:16.10 +24:51:22.3 45.94237 +0.15723 0.00133 -0.00858 0.00143
2009/12/11  09.40776 Keck 2/NIRC2 +03:55:31.61 +25:05:19.2 44.59040 -0.36534 0.00300 +0.03793 0.00300
2010/08/03  14.62292 Keck 2/NIRC2 +04:05:30.90 +25:26:34.0 45.95200 -0.03594 0.00600 -0.03938 0.00300
plus proprietary data                

Orbital knowledge

Comments: Orbit published here.
Parameter Value Units
P period139.652±0.002days
a semimajor axis9940±20kilometers
e eccentricity0.352±0.002dimensionless
i inclination35.27±0.09degrees
ε mean longitude at epoch224.7±0.1degrees
Ω longitude of ascending node312.0±0.2degrees
ϖ longitude of periapsis100.7±0.4degrees

Angles are referenced to J2000 equatorial coordinates.

Epoch = Julian date 2454300.0

2025/08/22 20:59


Last updated: 2025/08/22 20:59 UTC