2003 QB30 (small Apollo making close approach to Earth)
A: 5 images from 22:15:20 - 22:18:40
B: 5 images from 22:19:25 - 22:22:15
Each image is a 14 second exposure, stacked for motion of
18"/minute in p.a. 291°, field 2.5'x2.5', N up. Magnitude of NEO ~
+18.5. All CCD images were taken binned 2x2 and subsequently enlarged
x2.
This object was posted on the NEOCP
while other NEOs were already being imaged at Great Shefford on the evening of
24 Aug 2003.
At that time the uncertainty map on the NEOCP was indicating the
object could be in an area extending 1° East/West and 0.5°
North/South.
An initial set of 10 exposures was made centred on the nominal
ephemeris position and checked for the object, but nothing was found.
Before any futher exposures could be made the sky clouded over for the
rest of the night.
2003 QB30 was located by observers at the Klet observatory (246) on
exposures started at 22:01 UT and their observations allowed the MPC to
correct the original ephemeris, which changed the rate of motion from
13.5"/min to 17.7"/min. Fortunately this still placed it
within the 25'x25' field of the 10 images and by re-stacking them with
the updated motion the object was able to be detected and positions sent
of to the Minor Planet Center. Publication of MPEC
2003-Q29 followed later the same day.
The object itself is very small, with an absolute magnitude of ~+26.5
it is likely to have a diameter of between 13-30
metres.
When the above images were taken 2003 QB30 was 0.0186 AU from Earth
(about 7 times the mean distance of the moon), closest approach being
2.5 days later at 0.0051 AU from Earth (about double the distance of the
moon). Due to the geometry of the orbit the asteroid was observable for just 4 days after discovery.
See where this approach of 2003 QB30 fits in the list of closest
observed approaches by Minor Planets.
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