2019 GC6

2019 GC₆ is a very small near-Earth asteroid and potentially hazardous object of the Apollo group, approximately 20 meters (70 ft) in diameter. It was detected by the Catalina Sky Survey at Catalina Station on 9 April 2019, a few days before it made its first-observed pass through the cislunar region at a distance of 136,000 miles (219,000 km), comparable to roughly half the average distance from the Earth to the Moon (0.58 LD).^[4][5]

2019 GC₆

Discovery [1][2]
Discovered by	CSS
Discovery site	Catalina Stn.
Discovery date	9 April 2019
Designations
MPC designation	2019 GC6
Minor planet category	NEO · Apollo [1][2]
Orbital characteristics [2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 5[2] · 4[1]
Observation arc	17 days
Aphelion	1.2985 AU
Perihelion	0.9104 AU
Semi-major axis	1.1045 AU
Eccentricity	0.1757
Orbital period (sidereal)	1.16 yr (424 d)
Mean anomaly	317.32°
Mean motion	0° 50m 56.76s / day
Inclination	1.2557°
Longitude of ascending node	211.61°
Argument of perihelion	63.845°
Earth MOID	0.0015 AU (0.5844 LD)
Physical characteristics
Mean diameter	15 m (est. at 0.20)[3] 28 m (est. at 0.057)[3]
Absolute magnitude (H)	26.5[1] 26.51[2]

Orbit and classification

2019 GC₆ is a member of the Apollo group of asteroids, which are Earth-crossing asteroids. They are the largest group of near-Earth objects with approximately 10,000 known members. It orbits the Sun at a distance of 0.91–1.29 AU once every 14 months (424 days; semi-major axis of 1.1 AU). Its orbit has an eccentricity of 0.18 and an inclination of 1° with respect to the ecliptic.^[2]

The body's observation arc begins with its first observation by the Mount Lemmon Survey on 31 March 2019, just a few days prior to its potential discovery observation by the Catalina Sky Survey.^[1]

Physical characteristics

Diameter and albedo

The dimensions of the asteroid are estimated to range between 7.5–30 metres (25–98 ft) and has been compared to size of a house.^[4][5] Based on an magnitude-to-diameter conversion and a measured absolute magnitude of 26.5, 2019 GC₆ measures between 15 and 28 meters in diameter for an assumed geometric albedo of 0.20 (siliceous) and 0.057 (carbonaceous), respectively.^[1][3]