(471240) 2011 BT15

(471240) 2011 BT₁₅
Discovery
Discovered by	Pan-STARRS
Discovery site	Haleakala Obs.
Discovery date	24 January 2011
Designations
MPC designation	(471240) 2011 BT₁₅
Alternative designations	2011 BT₁₅
Minor planet category	NEO · PHA · Apollo
Orbital characteristics
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	9.63 yr (3,519 days)
Aphelion	1.6842 AU
Perihelion	0.9018 AU
Semi-major axis	1.2930 AU
Eccentricity	0.3025
Orbital period (sidereal)	1.47 yr (537 days)
Mean anomaly	204.24°
Mean motion	0° 40^m 13.08^s / day
Inclination	1.6613°
Longitude of ascending node	105.37°
Argument of perihelion	308.78°
Earth MOID	0.0008 AU · 0.3 LD
Physical characteristics
Mean diameter	0.136 km (calculated) 0.150 km
Mass	4.9×10⁹ kg (assumed)
Synodic rotation period	0.109138±0.000002 h
Geometric albedo	0.20 (assumed)
Spectral type	S
Absolute magnitude (H)	21.7

(471240) 2011 BT₁₅, provisional designation 2011 BT₁₅, is a stony, sub-kilometer sized asteroid and fast rotator, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group. It had been one of the objects with the highest impact threat on the Palermo Technical Impact Hazard Scale.