Ernesto Guido & Nick Howes
Wed, 06 Feb 2013 18:12 CST
, 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.
© Remanzacco Observatory
Here you can see a short animation
showing the movement of 2013 CL22 (three consecutive 15x15-second exposure).
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). Here you can see an animation
showing the daily Sky Coverage by professional surveys (in red) and the position of the asteroid (yellow dot).