Finding the Asteroid 2007 UR2 - Observations with Faulkes Telescope North
School students recover Martian companion using Faulkes Telescope
The
asteroid 2007 UR2 hadn't been observed in over 2 years, which means that predicting its orbit would be particularly uncertain, making this
asteroid quite difficult to find. 2007 UR2 is an
asteroid which has an extremely unusual horseshoe orbit associated with the planet Mars; this coupled with the lack of observations of this
asteroid makes our observations even more valuable.
In order to find this
asteroid we had to work out a line of prediction, rather than just taking one prediction. We found where this
asteroid was predicted to be on the
Minor Planet Center; however, we knew that this prediction was likely to be uncertain. We therefore decided to calculate positions 2 arc minutes and 6 arc minutes on either side of the predicted position to point the telescope, with the field of view being 4.7 arc minutes. In fact it turned out that the prediction was so uncertain that we found the
asteroid in the furthest position, 7 arc minutes away from the predicted position.
Line of variation search (+ marks predicted position, O marks actual position) - Images obtained using the Faulkes Telescope North, operated by Las Cumbres Observatory
We did all this planning the day before we used the telescope, and at 10.30 am on Thursday 21st January we took control of the
Faulkes Telescope North in Hawaii. Once we had finished our observing session, which was a little stressful seeing as we had never used a telescope before and had only half an hour to take 8 photographs. With the help of David and Tolis, timing that it took us exactly 3 minutes to take each photograph, we managed to take 9 photographs, taking three exposures of the last position, which incidentally turned out to be where our
asteroid was.
In order to distinguish between a star and our
asteroid, we had to take two images of the same position and then compare the two images to see if any of the apparent stars moved. The only way to tell the difference between the
asteroid and a star is that the
asteroid will move, and in order to tell if it is the
asteroid we want we need to check if the
asteroid was moving in the right direction from the predictions. When we looked at our images, after a quick tea break and a calm down after using the telescope, we realised that we had found two
asteroids from our observations. We thought, for a short period of time, that we might have actually found a new
asteroid. However, David quickly stole our thunder, by working out that it was actually a known main belt
asteroid (94020). Nonetheless, our observations were still very successful, as we worked out that the other
asteroid was indeed 2007 UR2, the
asteroid that we were looking for.
An animation showing the movement of 2007 UR2 - Images obtained using the Faulkes Telescope North, operated by Las Cumbres Observatory. Animation compiled by Apostolos Christou
In order to report our sightings to the Minor Planet Center, to improve predictions of the
asteroid's orbit, we had to observe the
asteroid again. So we spent the rest of the afternoon working out the exact location of the
asteroid in our images, and then comparing it to the prediction. We then knew by how much the predicition was out and therefore could work out exactly were the
asteroid would be. So, on Friday 22nd January at 10.00 am, we took control of Faulkes Telescope North, and pointed the telescope where we had newly predicted our
asteroid to be, and sure enough there it was. We now had enough information to send our observations to the Minor Planet Center.
When using the telescope on the second day we also had a chance to view some other interesting objects. We observed 2010 AH30, a near Earth
asteroid, and 2009 YS6, a damocloid. These observations were also sent to the Minor Planet Center.
We had such an amazing time taking control of the telescope, and we honestly cannot believe that we actually recovered an
asteroid, in 3 days of work experience at the Armagh Observatory. We would like to say a huge thank you to everyone at the Observatory, especially David Asher and Apostolos Christou, without whom we would have been completely lost, and confused.
Catherine O'Prey and Christina Larkin
2010 January 26th
More astronomical projects with the Faulkes Telescopes
Last Revised: 2010 February 2nd
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