2018 FC4

2018 FC₄
Discovery
Discovered by	Mt. Lemmon Survey
Discovery date	21 March 2018
Designations
MPC designation	2018 FC4
Minor planet category	Martian L5
Orbital characteristics
	Epoch 31 May 2020 (JD 2459000.5)
	Uncertainty parameter 0
Observation arc	790 days (2.16 yr)
Aphelion	1.5498684 AU (231.85701 Gm)
Perihelion	1.497823 AU (224.0711 Gm)
Semi-major axis	1.5238457 AU (227.96407 Gm)
Eccentricity	0.017077
Orbital period (sidereal)	1.88 yr (687.0841 d)
Mean anomaly	4.660°
Mean motion	0° 31m 26.232s /day
Inclination	22.1437°
Longitude of ascending node	187.55390°
Argument of perihelion	52.009°
Earth MOID	0.507683 AU (75.9483 Gm)
Jupiter MOID	3.41333 AU (510.627 Gm)
Physical characteristics
Dimensions	200 m
Geometric albedo	0.5-0.05 (assumed)
Absolute magnitude (H)	21.3

2018 FC₄ is a small asteroid and Mars trojan orbiting near the L₅ point of Mars (60 degrees behind Mars on its orbit).^[2]

Discovery, orbit and physical properties

2018 FC₄ was first observed on 21 March 2018 by the Mt. Lemmon Survey, but it had already been imaged (but not identified as an asteroid) by the Pan-STARRS 1 telescope system at Haleakala on the previous night.^[3] Its orbit is characterized by very low eccentricity (0.017), moderate inclination (22.1°) and a semi-major axis of 1.52 AU.^[3] Upon discovery, it was classified as Mars-crosser by the Minor Planet Center. Its orbit is reasonably well determined as it is currently (January 2021) based on 35 observations with a data-arc span of 790 days.^[1] 2018 FC₄ has an absolute magnitude of 21.3 which gives a characteristic diameter of 200 m.^[1]

Mars trojan and orbital evolution

Recent calculations indicate that it is a stable L₅ Mars trojan with a libration period of 1300 yr and an amplitude of 20°.^[2] These values are similar to those of 5261 Eureka and related objects and it may be a member of the so-called Eureka family.

Mars trojan

L₄ (leading):

(121514) 1999 UJ7 †

L₅ (trailing):

References

^ ^a ^b ^c "JPL Small-Body Database Browser: (2018 FC4)". Jet Propulsion Laboratory. Retrieved 12 January 2021.
^ ^a ^b de la Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.
^ ^a ^b MPC data on 2018 FC4

Further reading

Three new stable L5 Mars Trojans de la Fuente Marcos, C., de la Fuente Marcos, R. 2013, Monthly Notices of the Royal Astronomical Society: Letters, Vol. 432, Issue 1, pp. 31–35.
Orbital clustering of Martian Trojans: An asteroid family in the inner solar system? Christou, A. A. 2013, Icarus, Vol. 224, Issue 1, pp. 144–153.

External links

2018 FC₄ data at MPC.
2018 FC4 at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
2018 FC4 at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

[jpl-1] "JPL Small-Body Database Browser: (2018 FC4)". Jet Propulsion Laboratory. Retrieved 12 January 2021.

[dynamics-2] Fuente Marcos, Carlos; de la Fuente Marcos, Raúl (March 2021). "Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space". Monthly Notices of the Royal Astronomical Society. 501 (4): 6007–6025. arXiv:2101.02563. Bibcode:2021MNRAS.501.6007D. doi:10.1093/mnras/stab062.

[mpc-3] MPC data on 2018 FC4

[1]

[2]

[3]