Outer Planets in 2006

It’s a “piece of cake” to find Uranus and Neptune this year. Each planet happens to be in the low-power field of a naked-eye star plotted on the inset chart below. Aim your binoculars at that star, then use one of the close-up charts to ferret out the planet among others in the vicinity. These charts go to magnitude 10, much fainter than either planet.

Uranus’s reference star is 3.7-magnitude Lambda Aquarii. Currently magnitude 5.9, Uranus will brighten slightly to 5.7 for several weeks around its opposition to the Sun in early September. Neptune’s signpost is 4.3-magnitude Iota Capricorni. This planet, at magnitude 7.8 or 7.9 all year, comes to opposition in mid-August.

Pluto is a different story. Despite having its own naked-eye star nearby, 3.5-magnitude Xi Serpentis, this remote world usually needs a 10-inch (25-centimeter) telescope for identification. The challenge is to pick it out from the multitude of similarly faint stars shown on our chart below. Pluto remains at magnitude 13.9 for most of this year, reaching opposition in June.

© 2006 Reprinted with permission from Sky & Telescope.