The earth-approacher 2005 FN

The earth-approacher 2005 FN


2005 FN was discovered by LINEAR on 2005-03-17 and recognized at the Minor Planet Center (MPC) as an earth-approaching object with a very close encounter predicted on March 18. During the evening of March 17-18, several observatories in the U.S. followed 2005 FN and obtained astrometry to refine its orbit.

At New Mexico Skies Observatory, Jeffrey Sue and I tracked the object with the 0.25-m f/3.4 Takahashi Epsilon E250 Astrograph. With a predicted V magnitude of 15.6, we kept our exposures down to 10 seconds to minimize the signficant motion of 1"/second. Between 8:05 and 8:34 UTC, I shot two sets of 25 exposures of 10 seconds. Each set was processed into five stacks of five exposures using the measuring software Astrometrica. The following astrometry from MPEC 2005-F29 was derived from the ten stacks:

     K05F00N 6C2005 03 18.33690 13 15 51.83 -06 31 47.6          16.1 R EF029H06
     K05F00N 6C2005 03 18.33809 13 15 56.76 -06 30 36.1          15.7 R EF029H06
     K05F00N 6C2005 03 18.34028 13 16 05.85 -06 28 23.8          15.8 R EF029H06
     K05F00N 6C2005 03 18.34211 13 16 13.55 -06 26 33.1          15.7 R EF029H06
     K05F00N 6C2005 03 18.34408 13 16 21.85 -06 24 32.3          15.6 R EF029H06
     K05F00N 6C2005 03 18.35208 13 16 56.05 -06 16 14.3          15.9 R EF029H06
     K05F00N 6C2005 03 18.35325 13 17 01.15 -06 15 00.2          15.8 R EF029H06
     K05F00N 6C2005 03 18.35447 13 17 06.44 -06 13 43.0          15.8 R EF029H06
     K05F00N 6C2005 03 18.35585 13 17 12.46 -06 12 14.7          15.7 R EF029H06
     K05F00N 6C2005 03 18.35701 13 17 17.59 -06 11 00.0          15.9 R EF029H06

Animation of 2005 FN by Andrew Lowe at New Mexico Skies Observatory

Processing by Arnie Rosner

Each frame is a stack of five consecutive 10-second exposures, centered at 8:27:00, 8:28:41, 8:30:26, 8:32:25 and 8:34:06 UTC. During this time, 2005 FN was 0.0034 A.U. (509,000 kilometers = 316,000 miles) from the earth's center.