2020 MK53

2020 MK₅₃
DiscoveryMPS 1836391
Discovered by	New Horizons KBO Search-Subaru
Discovery site	Subaru
Discovery date	22 June 2020
Designations
MPC designation	2020 MK53
Minor planet category	TNO · SDO · distant
Orbital characteristics
	Epoch 24 June 2020 (JD 2459024.5)
	Uncertainty parameter 9
Observation arc	3 days
Aphelion	160 AU
Perihelion	63 AU
Semi-major axis	111 AU
Eccentricity	0.44
Orbital period (sidereal)	1174 yr
Mean anomaly	182°
Mean motion	0° 0m 2.88s / day
Inclination	18°
Longitude of ascending node	116°
Argument of perihelion	351°
Physical characteristics
Mean diameter	600–500 km (est. 0.1–0.2)
Apparent magnitude	25.6
Absolute magnitude (H)	4.12±0.35

2020 MK₅₃ is a trans-Neptunian object in the scattered disc, around 550 kilometres (340 miles) in diameter. It was discovered on 22 June 2020 by the New Horizons KBO Search-Subaru survey^[5]^[6] using the 8.2-meter Subaru Telescope of the Mauna Kea Observatories in Hawaii, and announced on 7 April 2023 (MPS 1836391, MPO 735634). It was 160 astronomical units from the Sun when it was discovered, making it the farthest known Solar System object from the Sun as of September 2023^[update], well ahead of 2018 VG18 (124 AU) and 2018 AG37 (~132 AU).^[2]^[7] Given its very short data-arc the only reliable information is in its range (156±4 AU) and range-rate (−0.04 km/s), which suggests that it is close to its aphelion.^[8]^{[failed verification]}

References

^ ^a ^b "JPL Small-Body Database Browser: (2020 MK53)" (2020-06-25 last obs.). Jet Propulsion Laboratory. Retrieved 9 September 2023.
^ ^a ^b ^c ^d "2020 MK53". Minor Planet Center. International Astronomical Union. Retrieved 9 September 2023.
^ "Distant objects". Minor Planet Center. International Astronomical Union. Retrieved 10 September 2023.
^ "Asteroid Size Estimator". Center for Near Earth Object Studies. Jet Propulsion Laboratory. Retrieved 31 May 2022.
^ "Subaru Telescope and New Horizons Explore the Outer Solar System". Subaru Telescope. Retrieved 10 September 2023.
^ "New Horizons Team Adds AI Smarts to Its Kuiper Belt Object Search". NASA/Johns Hopkins APL/Southwest Research Institute/Subaru Telescope. National Aeronautics and Space Administration. 6 March 2023. Retrieved 10 September 2023.
^ "JPL Horizons On-Line Ephemeris for 2020 MK53". JPL Horizons On-Line Ephemeris System. Jet Propulsion Laboratory. Retrieved 9 September 2023. Ephemeris Type: VECTORS, Target Body: Asteroid (2020 MK53)
^ C. de la Fuente Marcos & R. de la Fuente Marcos (1 January 2024). "Past the outer rim, into the unknown: structures beyond the Kuiper Cliff". Monthly Notices of the Royal Astronomical Society Letters. 527 (1): L110 – L114. arXiv:2309.03885. Bibcode:2024MNRAS.527L.110D. doi:10.1093/mnrasl/slad132. Retrieved 28 September 2023.