On the night of 2003 September 13/14th the Minor Planet Center's
NEO Confirmation page
a number of newly discovered objects listed as requiring observation and four were imaged
during that evening from Great Shefford.
Three turned out to be new NEO objects and were eventually designated
The last one attempted that evening had a temporary designation of
59D002, the normal style of designation given by discoveries from the
Lowell Observatory LONEOS survey. It was listed as being of magnitude +17.3 and travelling almost
due south at 1.7"/minute. As usual, a series of images was taken and
then stacked together into three sets, taking into account the known motion of the object and then blinked using Astrometrica to try and reveal the
When the images were examined an object of about the right brightness
could be seen moving south as expected, but about 7' to the west of the
predicted place. Seconds later another object also about the right
brightness and moving south was noticed, much nearer the predicted
59D002 was presumed to be the second object and the MPC's
Minor Planet Checker
web service was used to see which known asteroids were in the
vicinity of the first object.
There were four asteroids within a degree of the new object, three
had well determined orbits having been seen at three or more
oppositions. The closest of these was 23' away and obviously none of the
three could be identified with the first object..
The remaining known object listed by the Minor Planet Checker was
2003 QJ5, discovered on 2003 Aug 21st. It had appeared on the NEOCP at
that time, but was determined not to be a NEO and so was taken off the
page on Aug 22nd. and had remained unobserved since that time. Although
the predicted place of 2003 QJ5 was by now rather off track the MPC
quickly established that 59D002 was the same as 2003 QJ5 and took 59D002
off the NEOCP less than an hour after I had taken my first image of it.
There was no known asteroid that could be identified with the new object
I had found! I gave it a temporary designation of GS0304 and sent the
astrometry off to the MPC just after midnight local time. About half an
hour later the MPC indicated it looked like a new one.
This is the boxed area above as a stack of four frames compensating
for the motion of 2003 RV10, with both 2003 QJ5 and 2003
RV10 marked. Click
on the image for an animation (241k).
Field approx. 9'x6', North up, taken 2003 Sep
13 22:22 - 22:30 UT
Four images each of 30 seconds exposure stacked to compensate for the
motion of 2003 RV10 (and 2003 QJ5).
Follow-up positions were required on a second night to confirm
whether the new object was indeed a new discovery. I was fully expecting
another observatory that may have been imaging 59D002 that same night to
manage to follow up and confirm the object before me.
Luckily the next night Sept 14/15 was clear and more positions were
obtained. These were sent off to the MPC and a few hours later they sent
back the designation GS0304 = 2003 RV10, indicating that it had been
credited as a new discovery from Great Shefford!
(Luckily, as it turned out, only one other observatory had reported
positions of 2003 QJ5 that first night and that observatory had not
submitted positions for 2003 RV10).
With just two days of positions the MPC published a Väisälä orbit
(calculated assuming that the object is at perihelion at the moment of
one of the observations). This is often a good assumption with a newly discovered
asteroid, but can only predict positions approximately more than a few
days into the future. More astrometry was therefore obtained the next
night and with three nights the MPC published a general orbit for 2003
RV10 and managed to link it to three positions reported three weeks
earlier from the NEAT survey at Palomar. As no other observations were
made at that time it could not be attributed to NEAT and was left as a
one night stand.
2003 RV10 has a moderately eccentric orbit (e=0.29) and inclination (i=30°)
and was at its closest to the sun two months before discovery, at the end of June
It will be a difficult object to follow after this opposition,
only reaching magnitude 20.7 at its next opposition in winter 2004/5.
It will be July 2007 before it returns with similar brightness to 2003.
If you can make follow-up observations then click here to generate an
ephemeris, they would be very welcome.