2019 OU1

2019 OU₁^[a] is a sub-kilometre asteroid, classified as a near-Earth object of the Apollo group.^[1][2] On 28 August 2019, the object safely passed 1.028 million kilometres from Earth,^[3] travelling at around 13 km/s (47,000 km/h).^[2]

2019 OU₁

Discovery[1]
Discovered by	Pan-STARRS 1
Discovery site	Haleakala Obs.
Discovery date	25 July 2019 (first observed)
Designations
MPC designation	2019 OU1
Minor planet category	Apollo · NEO [1][2]
Orbital characteristics[1][2]
Epoch 27 April 2019 (JD 2458600.5)
Uncertainty parameter 6[2] · 7[1]
Aphelion	3.673 au
Perihelion	0.5748 au
Semi-major axis	2.2679 au
Eccentricity	0.61977
Orbital period (sidereal)	3.42 years
Mean anomaly	313.73°
Mean motion	0° 17m 18.916s / day
Inclination	2.2176°
Longitude of ascending node	145.143°
Argument of perihelion	241.08°
Earth MOID	0.0062 au (2.4 LD)
Jupiter MOID	1.79 au
Physical characteristics
Mean diameter	71 m[3] (est. at 0.25)[4] 160 m[5] (est. at 0.05)[4]
Absolute magnitude (H)	22.87[2]

Observation

2019 OU₁ was first observed on 25 July 2019 by Pan-STARRS 1 at Haleakala Observatory, Hawaii, United States.^[1]

Orbit and classification

2019 OU₁ is classified as an Apollo asteroid, which means that it is an Earth-crossing asteroid that has an orbital semi-major axis greater than 1 au but a perihelion distance less than Earth's aphelion distance of 1.017 au.^[6]

Close approach in 2019

On 28 August 2019, 2019 OU₁ safely passed 0.00687 astronomical units (1.028 million kilometres; 2.67 lunar distances) from Earth,^[3] travelling at around 13 km/s (47,000 km/h).^[2]

Physical characteristics

Based on its absolute magnitude of 22.874,^[1] 2019 OU₁ is estimated to have a diameter of 71–160 metres^[5] using an assumed albedo of 0.05 (carbonaceous) and 0.25 (siliceous) respectively.^[4]

See also

• List of asteroid close approaches to Earth in 2019
• 2006 QQ23
• 2019 OK

Notes

1. The name 2019 OU₁ is its provisional designation which is based on the date it was discovered: 2019 for the year, "O" for half-month of 16–31 July, and "U₁" for the 21st discovery in the 1st reiteration of the alphabet (excluding "I"), making it the 45th object discovered in the second half of July 2019.