Uranus, Neptune, and Pluto in 2003

Location of Uranus and Neptune in 2003
Click on the image to see a finder chart for Uranus.
Sky & Telescope illustration.
Uranus is in Aquarius and Neptune is in neighboring Capricornus this year. Skywatchers should have no trouble finding them with binoculars and the charts in this article. They include stars to magnitude 10.0, much dimmer than either planet. The tick marks on the planets’ paths give their location on the first of each month.

Uranus hovers at magnitude 5.7 for a few weeks around the time of its opposition to the Sun on August 23–24. So it might even be glimpsed with the naked eye. In mid-April the planet passes just 6' south of a 13th-magnitude galaxy.

Finder chart for Neptune
Click on the image to see a chart that includes the path of Mars during mid-May, 2003.
Sky & Telescope illustration.
Neptune is easy to find near its own opposition date, August 3–4, at magnitude 7.8. But even before and after that it never dips below 8.0. Most of the year 4.2-magnitude Theta (q) Capricorni is the obvious stepping-off point for locating Neptune, but during the second week of May the brilliant planet Mars can play this role. (Tick marks on Mars’s path are for 0h Universal Time on each date.) Neptune approaches to within 3' southwest of a cigar-shaped galaxy, 13th-magnitude IC 5078, in mid-May. Their rendezvous could make for an interesting CCD-image sequence. Neptune happens to be the farthest planet from Earth then, but the galaxy is at least 100 billion times farther still.

Sky & Telescope illustration.
Pluto is a far greater telescopic challenge than either Neptune or Uranus. At least an 8-inch glass and very dark skies are needed to spot this tiny, outlying world. It shines at 13.9 magnitude most of the year, brightening to 13.8 around opposition on June 9–10. Only a single star on the large finder chart, 4.3-magnitude Nu (n) Serpentis, is readily visible to the naked eye. So it can serve for star-hopping to this planet. In early June Pluto passes just ½° south of NGC 6309, the Box Nebula (click on the image at left to see a large finder chart for Pluto).

Despite some close calls shown on our chart, neither Pluto nor its moon Charon is predicted to occult a star in 2003. Such events can reveal remarkable information about the planet's atmosphere —
Sky & Telescope: January 2003, page 30 (News Notes).

The charts used here can be found in the article "Outer Planets in 2003" in the April 2003 issue of Sky & Telescope.