2010 JL33 was discovered by Rik Hill (during the course of the Catalina Sky Survey) using the 1.5-m reflector at Mt.Lemmon on 2010, May 06.37. It was promptly catalogued as a PHA.
The asteroid passed to perigee on 2010, Dec. 09 at a distance of about 0.0427 AU (6.4 million Km or 17 times the Moon distance).
Here is an animation from our observation on 2010, Dec. 10.90:
These images were taken just one day before NASA radar team imaged it with Goldstone antenna (see image below), revealing the shape of this 1.8-km asteroid.
The news can be seen at http://www.jpl.nasa.gov/news/news.cfm?release=2011-011.