Potentially Hazardous Asteroid 415029 (2011 UL21)

Asteroid 415029 (2011 UL21) is a mid-sized asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 2011 UL21 as a "Potentially Hazardous Asteroid" due to its predicted close passes with Earth.

2011 UL21 orbits the sun every 3.09 years, coming as close as 0.74 AU and reaching as far as 3.51 AU from the sun. It is probably between 1.693 to 3.785 kilometers in diameter, making it larger than 99% of asteroids.

http://www.astrobin.com/users/bellavia/collections/

Astro-Physics Starfire 154
Fornax 152
ZWO ASI 183MC camera

11 separate images, combined into one