The asteroid 2004 BL86 passed the Earth on Jan 26 2015

Late January the asteroid 2004 BL86 was in a close encounter with our planet Earth. During the closest approach at night from 26 to 27 January 2015 about 16:20 UT the asteroid was merely 1.2 mln km (more or less 3 times Earth-Moon distance) from Earth and reached luminosity about +9 magnitudo. On this time the astreoid was visible from Europe, Africa and both Americas.

Near its best visibility the planetoid crossed constellations of Hydra and Cancer, as one can see on the map, made by Janusz Wiland in his own programm The Night Observer, which is shown below. On the map there are marks of the close passes near bright stars, in CET time zone, UT+1 (click on the map to enlarge):

The map with the trajectory of asteroid 2004 BL86 during its closest approach to Earth in late January 2015
The map with the trajectory of asteroid 2004 BL86 during its closest approach to Earth in late January 2015

We perfrormed observations of the asteroid from our south observatory in San Pedro de Atacama, where it was visible during the whole night, but unfortunately not in its maximum brightness, when there was daytime in Americas.

Below there are two MP4 movies composed from frames taken between about 3:09 and 6:30 UT, when the asteroid was passing the famous M44 open cluster in Cancer (which is in the middle of the frames). Each frame is an average of 5 consecutive frames, so each frame covers about one minute of time. The colours are unnatural, to asteroid 2004 BL86 be better visible.

The first movie shows all frames, taken by our camera cam37, in which the asteroid is visible. The asterod is clearly crossing the very center of the frames, from bottom to top (40 MB):

 

 

The second one movie shows center of the trajectory in close-up. The movie covers time between 3:58 and 5:44 UT (19 MB):