A group of amateur astronomers has used the 2.1-meter (82-inch) Otto Struve Telescope at McDonald Observatory to make the first ‘through-the-eyepiece’ sighting of so-called the tenth planet, an object orbiting the Sun in the Kuiper Belt, far beyond Pluto. The group includes members of the St. Louis and Rockland Astronomical Societies, and a few others.
The [...]

Although the IAU determined in late 2005 that an object can be considered a planet if it is at least the size of Pluto, it decided to ask the Division of Planetary Sciences (DPS) of the American Astronomical Society for its recommendation as well. The IAU will be meeting in Prague in August, 2006, [...]

The University of Bonn, using a 30-meter IRAM telescope, have determined that 2003 UB313 has a diameter of 3000 +/- 400 km. Like Spitzer, IRAM measures the heat given off from the object, but IRAM is a much larger telescope than Spitzer. Due to its size, it was able to measure the [...]