Article: "Amateur and Professional Astronomers Cooperate to Map Dancing Asteroid"

Selections from the article:

The motions of an asteroid with two whirling parts are now better known, thanks to a rare collaboration between professional and amateur astronomers.

Called 90 Antiope, the asteroid consists of two egg-shaped rubble piles locked in orbit, like two twirling dancers facing one another with linked arms. Antiope is thought to be the remnants of a larger asteroid, dubbed Themis, which astronomers think was destroyed by an impact with another asteroid some 2.5 million years ago.

The finding is detailed in the April 2007 issue of the scientific journal Icarus.

Using the 10-meter Keck II telescope in Hawaii, astronomers discovered in 2000 that Antiope, once thought to be a typical asteroid floating between the orbits of Mars and Jupiter, actually consists of two gravitationally linked space rocks.

Subsequent observations by Keck II and the Very Large Telescope in Chile determined the orbits of Antiope’s two parts, each of which were found to be about 53 miles (86 km) in diameter and separated by about 106 miles (171 km).

“Amateurs can be used for professional studies, compensating for the small size of their telescopes by the large number of observations and the frequency of observations they can do,” said study team member Franck Marchis, an astronomer at the University of California, Berkeley.

"Amateur and Professional Astronomers Cooperate to Map Dancing Asteroid"
Ker Than
Staff Writer
Space.com
29 March 2007

Link: Article on Space.com