Close Approach of Asteroid 2013 CL22

M.P.E.C. 2013-C24, issued on 2013 Feb. 6, reports the discovery of the asteroid 2013 CL22 (discovery magnitude 16.7) by J75 OAM Observatory, La Sagra on images taken on February 05.06 with a 0.45-m f/2.8 reflector + CCD. 

2013 CL22 has an estimated size of 30 m - 68 m (based on the object's absolute magnitude H=24.7) and it had a close approach with Earth at about 1.2 LD (Lunar Distances = ~384,000 kilometers) or 0.0031 AU (1 AU = ~150 million kilometers) at 0743 UT on 2013 Feb. 02. This asteroid reached the peak magnitude ~13.1 on February 02 around 1600 UT.

We performed some follow-up measurements of this object, from the H06 ITelescope network (near Mayhill, NM) on  2013, Feb. 05.4, through a 0.51-m f/6.9 reflector + CCD. Below you can see our image, stack of 15x15-second exposure, taken with the asteroid at magnitude ~16.9 and moving at ~6.07 "/min. At the moment of the close approach 2013 CL22 was moving at ~ 259"/min. Click on the image below to see a bigger version. 

Below you can see a short animation showing the movement of 2013 CL22 (three consecutive 15x15-second exposure). Click on the thumbnail for a bigger version:

This asteroid has gone unnoticed through its close approach. In the period from January 30 to February 05 (discovery date) the asteroid was brighter than magnitude 20 (mag. ~19.8 on Jan. 30, ~18.4 on Jan. 31, ~15.6 on Feb. 01, ~13.5 on Feb. 02, ~15.9 on Feb, 03). Below you can see an animation showing the daily Sky Coverage by professional surveys (in red) and the position of the asteroid (yellow dot). Click on the thumbnail below to see a bigger version:

by Ernesto Guido & Nick Howes