Usually I update this blog with some interesting stuff done at Schiaparelli Observatory, but this time I will make an exception.
On July 27 a team led by Martin Connors of Athabasca University in Canada announced the discovery of the first Earth Trojan asteroid, 2010 TK7. Their work appeared in the current issue of the journal Nature.
2010 TK7 was originally discovered by NASA WISE survey on 2010, Oct. 01, then placed on the MPC NEO Confirmation Page, allowing astronomers to obtain some follow-up. It was observed for a 6-days arc, then recovered by Christian Veillet et al. using Canada-France-Hawaii Telescope on 2011 April 28-29, when it was at mag. 23.2 r.
Those observations were crucial to identify 2010 TK7 as the first Earth Trojan asteroid, which currently reside around L4 Lagrangian point, so leading the Earth in its orbit around
the Sun. It is estimated to be 150-500 meters across, depending on its albedo (from 0.25 to 0.04 respectively).
On Aug. 3, thanks to the Faulkes Telescopes collaboration (P. Miller, P. Roche, A. Tripp,
R. Miles, R. Holmes, S. Foglia and myself), I’ve been able to image it with the 2.0-m f/10
Faulkes Telescope North at Haleakala, in very good sky conditions (3% humidity, 1.1″ seeing, excellent transparency).
The result is below:
Now 2010 TK7 is in the southern constellation Fornax, so quite a bad place for northern observatories. In the next months it will be even worse, reaching declination -50° in November. Then it will start to move north, but never brighter than V=21 and less than 90° from the Sun.