MPMLers:

I want to tell you about a really interesting asteroidal object found at
the Lowell Observatory Near-Earth-Object Search (LONEOS).

LONEOS has a collaborative arrangement with a group called Minor Planet
Research (http://www.minorplanetresearch.org). We frequently shoot a few
frames for MPR's exclusive use in its educational outreach program, and
we send the image data to MPR representative Bob Cash, who examines them
using a version of PinPoint that Bob Denny has customized for LONEOS
data.

Two nights ago, Brian Skiff imaged some fields and sent them to Cash,
who was able to detect an 18th magnitude object moving at 20 deg/day on
three of four frames. (Had we analyzed the frames ourselves, we would
have missed the object as it was not present on all four frames and was
moving faster than our cutoff rate of motion.) Cash submitted the data
to the Minor Planet Center, and the object appeared as P00ACE on the
NEO Confirmation Page.

We noticed that the orbit was quite well defined, in spite of the very
short orbital arc of 41 min, and hoped to reimage the object the next
night (2003 Sep 29 UT). We reckoned the ephemeris uncertainty to be
about 6 arcmin (1 sigma), almost entirely in RA.

Skiff acquired fresh frames on the 29th, and Bruce Koehn and I examined
the region of interest visually. The main problem was that P00ACE had
likely faded by 3 mag, and would perhaps be more than 1 mag fainter than
our normal survey limit of R = 19.3. We failed to find it.

Bob Cash returned home from work yesterday evening at 11:15 p.m. and set
about examining the frames, also visually. After some effort, he
succeeded in detecting some just-believable images on all four frames,
about 3 sigma from the nominal ephemeris position.

Here are the observations:

P00ACE C2003 09 28.39534 00 57 28.55 +10 45 58.8 18.1 R 699
P00ACE C2003 09 28.40955 00 56 16.42 +10 45 37.5 18.4 R 699
P00ACE C2003 09 28.42381 00 55 08.57 +10 45 13.5 18.4 R 699
P00B3F C2003 09 29.15524 00 37 18.68 +10 39 51.7 22.0 R 699
P00B3F C2003 09 29.16354 00 37 11.92 +10 39 56.6 21.8 R 699
P00B3F C2003 09 29.17187 00 37 04.81 +10 39 59.3 19.4 R 699
P00B3F C2003 09 29.18017 00 36 57.76 +10 40 04.4 21.4 R 699

And here is the orbit:

P00ACE
Epoch 2003 Dec. 27.0 TT = JDT 2453000.5 Bowell
M 84.09058 (2000.0) P Q
n 0.58964717 Peri. 280.56241 +0.26088733 +0.96535827
a 1.4084494 Node 4.56809 -0.86155637 +0.23498211
e 0.4747901 Incl. 3.31550 -0.43549790 +0.11343204
P 1.67 H 30.6 G 0.15 U 9
Residuals in seconds of arc
030928 699 0.8- 0.5- 030929 699 3.6- 0.3- 030929 699 1.6+ 0.6+
030928 699 1.4+ 0.2+ 030929 699 1.0+ 0.4+
030928 699 0.6- 0.4+ 030929 699 0.9+ 0.8-

P00AC 0.15K03863883163280562405300456809250033154954 7397315310474790113
K03CRP00AC 30.6 K03CR 84.1 280.6 4.6 3.3 0.475 1.408 1 1
7 Bowell MPC xxxxx K039S K039T 1.24 h M-v 003E 99999

Note that the absolute magnitude H of this object puts it in the 2- to
5-m diameter range---SUV or room size---and may make it the smallest
object for which we have a reasonably good orbit. Note also that a
close Earth approach of 0.0006 AU, about a quarter of the Moon's
distance, occurred on 2003 09 27.94. The object was moving at more than
30 deg/hr and was about magnitude R = 16.5 at the time. The object's
mean orbital intersection distance with Earth (MOID) was about
0.0002 AU before Earth encounter.

If someone has access to a 2-m or larger telescope tonight, and might
be able to image the object, please let me know and I'll generate a
topocentric ephemeris. It'll be moving at 1.3 deg/day and will have
R ~ 22.8 mag.

Cheers...Ted