Pluto in 2013
Pluto was originally thought of as the smallest, and usually the outermost, of the major planets. With the discovery beyond Neptune of a number of other objects of the same sort of size, opinion swung to thinking of it as one of the larger Kuiper belt objects. Some of these, like Pluto, have a period in the ratio 3:2 with Neptune.
At the 2006 IAU meeting in Prague it was decided to reclassify the larger of these object, including Pluto, as Dwarf Planets. Whether the name will stick remains to be seen.
In 2013, Pluto's apparent path will be in Sagittarius about 3.5° south of its boundary with Scutum. During 2013 Pluto will be moving through the Milky Way with numerous background stars with a similar magnitude to the planet. This is likely to make its detection and identification more difficult than when it there are less background stars. In January 2013, Pluto will skirt the southern edge of the M25 star cluster but will then be too close to the Sun to observe.
Pluto is stationary on April 13 after which its motion will be retrograde, back to the west, for the next 5 months. The planet is at opposition on July 2. Pluto is stationary again on September 20, when it will start moving to the east again. After opposition Pluto will be an evening object. It will be lost to view in the evenig twiliht by about the beginning of December, reaching conjunction with the Sun on 1 January 2014.
At present, Pluto is a 14th magnitude object, so is likely to need a telescope with an aperture of at least 25 cm to see. Keen eyed observers viewing under good conditions from a dark site may be able to spot the planet with a smaller telescope. The planet is at opposition on June 29. Thus May, June, July and August will be the best time for attempting to view it. It is in conjunction with the Sun on 30 December 2012 and on 1 January 2014, so starts and ends the year too close to the Sun to observe.
Finder chart for Pluto in Sagittarius during 2013.The view is for the southern hemisphere with south at the top and east to the right.
The circle shows a field with a five degree diameter. Stars to magnitude 9.0 are shown, those to magnitude 7.5 are labelled.
Detailed path of Pluto in Sagittarius during 2013.The view is for the southern hemisphere with south at the top and east to the right.
The circle shows a field half a degree in diameter.
Stars to magnitude 11.0 are shown, those brighter than magnitude 9 are labelled without a decimal point. Some fainter stars are also labelled.
Pluto is marked on its path at its position on January 1 and again at its opposition position on July 2.
Charts generated with the assistance of GUIDE 8.0 produced by Project Pluto.
Positions of Pluto during 2013