(5638) Deikoon
This object has a more recent orbit available here
Object
Object | (5638) Deikoon |
Diameter(1) | 47 km |
Dynamic class(1) | trojan |
Absolute magnitude | 10.50 |
G slop | 0.15 |
(1) Data from the johnston archive list.
Orbital elements
Epoch (Julian date) | 2458200.5 |
Semi major axis | 5.248985 ± 0.000000 au |
Eccentricity | 0.107235520 ± 0.000000025 |
Inclination | 10.908381792 ± 0.000000318 ° |
Longitude of ascending node | 156.019725 ± 0.000005 ° |
Argument of perihelia | 91.816618 ± 0.000009 ° |
Mean anomaly | 260.334573 ± 0.000009 ° |
Orbital period | 12.03 yr |
Ephemeris & Observations
Ephemeris version | NIMAv5 |
Observation file |
omc_ast_NIMAv5.txt |
bsp file | 5638_Deikoon_nima_v5.bsp |
Date of first observation | 1988-08-18 |
Date of last observation | 2020-08-11 |
Number of observations used in the fit | 2248 |
Number of rejected observations | 9 |
Number of DES observations | 10 |
Number of MPC observations | 1976 |
Number of unpublished observations | 2 |
RMS of observations | 0.091 arcsec |
Residuals

Residuals in right ascension and declination compared to NIMAv5 ephemeris.
Colours indicate the estimated precision in arcsec used as weights in the fitting process.
Orbit quality
date | σα (arcsec) | σδ (arcsec) |
2021-01 | 0.007 | 0.002 |
2021-07 | 0.013 | 0.002 |
2022-01 | 0.013 | 0.002 |
2022-07 | 0.024 | 0.002 |
2023-01 | 0.018 | 0.002 |
2023-07 | 0.028 | 0.006 |
2024-01 | 0.021 | 0.004 |
2024-07 | 0.025 | 0.007 |
2025-01 | 0.022 | 0.006 |
Ephemeris comparison

Difference between NIMAv5 and JPL36 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.