Ceres and Vesta in 2011

Vesta and Ceres, the two brightest asteroids, are normally far from each other in the sky. But swift Vesta, with an orbital period of 3.6 years, is catching up to slower Ceres, with its 4.6-year orbital period. This year (2011), Vesta is in Capricornus, while Ceres is just 1½ constellations east on the Aquarius/Cetus border. In 2012 they will be side by side in Taurus.

Click above to download a full-page, printable finder chart for Ceres and Vesta in 2011.
Sky & Telescope diagram
Click here to download a full-page printable chart for Ceres and Vesta in PDF form.

Vesta passed through opposition August 6th; Ceres will do so September 16th. This is when each is about at its nearest and brightest, and when it rises around sunset and is highest around the middle of the night.

This is an extraordinarily good apparition for Vesta, which was magnitude 5.6 around opposition — just about as bright as it can ever get. This is also a banner year for Vesta because NASA's Dawn spacecraft is due to start orbiting it in July and begin high-resolution mapping in August.

The magnitudes of the asteroids on selected dates are listed below.

June 19.16.8
July 18.76.3
August 18.45.7
September 17.86.3
October 17.87.0
November 18.47.5
December 18.77.9