(5638) Deikoon


Object

Object (5638) Deikoon
Diameter(1) 47 km
Dynamic class(1) trojan
Absolute magnitude 10.61
G slop 0.15
(1) Data from the johnston archive list.

Orbital elements

Epoch (Julian date) 2460800.5
Semi major axis 5.230335 ± 0.000000 au
Eccentricity 0.105876898 ± 0.000000015
Inclination 10.920455217 ± 0.000000400 °
Longitude of ascending node 156.033321 ± 0.000005 °
Argument of perihelia 92.452429 ± 0.000008 °
Mean anomaly 113.581143 ± 0.000005 °
Orbital period 11.96 yr

Ephemeris & Observations

Ephemeris version NIMAv9
Observation file (documentation) omc_ast_NIMAv9.txt
bsp file 5638_Deikoon_nima_v9.bsp
Date of first observation 1988-08-18
Date of last observation 2025-07-07
Number of observations used in the fit 4420
Number of rejected observations 70
Number of DES observations 10
Number of MPC observations 4126
Number of unpublished observations 76
RMS of observations 0.117 arcsec

Residuals

residual plot

Residuals in right ascension and declination compared to NIMAv9 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.

Orbit quality

date σα (arcsec) σδ (arcsec)
2024-01 0.015 0.004
2024-07 0.019 0.006
2025-01 0.017 0.005
2025-07 0.018 0.005
2026-01 0.019 0.005
2026-07 0.018 0.004
2027-01 0.022 0.005
2027-07 0.017 0.003
2028-01 0.024 0.003

Ephemeris comparison

residual plot

Difference between NIMAv9 and JPL58 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.

Previous NIMA versions