2011 KW48

2011 KW₄₈
Discovery
Discovered by	New Horizons KBO Search (266)
Discovery site	Subaru Telescope
Discovery date	29 May 2011; (discovery: first observed only)
Designations
MPC designation	2011 KW48
Alternative designations	VNH0004
Minor planet category	TNO · inner classic; distant
Orbital characteristics
	Epoch 8 June 2011 (JD 2455720.5)
	Uncertainty parameter n.a.
Observation arc	34 days
Aphelion	42.676 AU
Perihelion	32.368 AU
Semi-major axis	37.522 AU
Eccentricity	0.1374
Orbital period (sidereal)	229.84 yr (83,950 days)
Mean anomaly	347.91°
Mean motion	0° 0m 15.48s / day
Inclination	3.6328°
Longitude of ascending node	246.15°
Argument of perihelion	46.931°
Physical characteristics
Mean diameter	77 km
Geometric albedo	0.09 (estimate)
Absolute magnitude (H)	8.8

2011 KW₄₈, temporarily designated VNH0004, is a trans-Neptunian object from the inner classical part of the Kuiper belt, located in the outermost region of the Solar System. It measures approximately 77 kilometers (48 mi) in diameter.

The object was first observed on 29 May 2011, during the New Horizons KBO Search (266) conducted by astronomers using the Subaru Telescope at the Mauna Kea Observatory on Hawaii, United States.^[3] It was later observed by the New Horizons space probe from afar in January 2015.^[4]^[5]

Orbit and classification

2011 KW₄₈ orbits the Sun at a distance of 32.4–42.7 AU once every 229 years and 10 months (83,950 days; semi-major axis of 37.5 AU). Its orbit has an eccentricity of 0.14 and an inclination of 3.6° with respect to the ecliptic.^[1]

This object was observed 12 times by the Mauna Kea (8) and Las Campanas (4) observatories over a period of about 33.8 days between 29 May and 2 July 2011. Because of this short period of observation, its current orbit is extremely uncertain.^[1]^[3]

New Horizons

Between 4–15 January 2015,^[4] the New Horizons spacecraft actively observed this object – then temporarily designated VNH0004 – at a distance of about 0.5 AU (75 million km; 46 million mi).^[5] While this was too far to resolve surface features or perform spectroscopic analyses of its composition, the spacecraft was able to search for possible satellites and observe its phase curve.^[5]

Physical characteristics

Based on an absolute magnitude of 8.8,^[1] and an assumed albedo of 0.09, the Johnston's archive estimates a mean diameter of approximately 77 kilometers (48 mi).^[2] As of 2018, no rotational lightcurve of 2011 KW₄₈ has been obtained from photometric observations. The object's rotation period, pole and shape remain unknown.^[1]^[6]