(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 9.71
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2460600.5
Semi major axis 5.291312 ± 0.000000 au
Eccentricity 0.022272313 ± 0.000000013
Inclination 28.758235904 ± 0.000000141 °
Longitude of ascending node 120.548423 ± 0.000000 °
Argument of perihelia 286.543039 ± 0.000022 °
Mean anomaly 68.619491 ± 0.000018 °
Orbital period 12.17 yr

Ephemeris & Observations

Ephemeris version NIMAv2
Observation file (documentation) omc_ast_NIMAv2.txt
bsp file 15440_Eioneus_nima_v2.bsp
Date of first observation 1951-11-28
Date of last observation 2024-05-04
Number of observations used in the fit 4043
Number of rejected observations 66
Number of DES observations 0
Number of MPC observations 3651
Number of unpublished observations 0
RMS of observations 0.122 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv2 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2024-01 0.021 0.009
2024-07 0.017 0.006
2025-01 0.028 0.006
2025-07 0.021 0.004
2026-01 0.030 0.001
2026-07 0.025 0.001
2027-01 0.028 0.008
2027-07 0.027 0.006
2028-01 0.025 0.010

Ephemeris comparison

residual plot

Difference between NIMAv2 and JPL64 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.