(15440) Eioneus


This object has a more recent orbit available here

Object

Object (15440) Eioneus
Diameter(1) 63 km
Dynamic class(1) trojan
Absolute magnitude 9.69
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2460200.5
Semi major axis 5.293441 ± 0.000000 au
Eccentricity 0.023073420 ± 0.000000014
Inclination 28.751815657 ± 0.000000140 °
Longitude of ascending node 120.552094 ± 0.000000 °
Argument of perihelia 286.227107 ± 0.000022 °
Mean anomaly 36.467846 ± 0.000019 °
Orbital period 12.18 yr

Ephemeris & Observations

Ephemeris version NIMAv1
Observation file (documentation) omc_ast_NIMAv1.txt
bsp file 15440_Eioneus_nima_v1.bsp
Date of first observation 1951-11-28
Date of last observation 2023-11-18
Number of observations used in the fit 3430
Number of rejected observations 15
Number of DES observations 0
Number of MPC observations 2987
Number of unpublished observations 0
RMS of observations 0.122 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv1 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2023-01 0.014 0.006
2023-07 0.013 0.006
2024-01 0.022 0.009
2024-07 0.018 0.007
2025-01 0.029 0.007
2025-07 0.022 0.005
2026-01 0.032 0.001
2026-07 0.026 0.001
2027-01 0.029 0.008

Ephemeris comparison

residual plot

Difference between NIMAv1 and JPL61 in right ascension (weighted by cos δ) and in declination.
Gray area represents the 1-σ uncertainty of NIMA ephemeris. Green dots represent the DES observations.