Melpomene at Opposition in 2009

Melpomene will be in Pisces, very close to its border with Cetus, when it brightens to magnitude 9.5 late in July 2009. It will then still be moving in an easterly direction. The asteroid crosses into Cetus on August 5 and reaches a stationary point on September 15 after which Melpomene will start moving in a retrograde sense to the west, caused by the Earth beginning to overtake the slower moving asteroid.

Melpomene is at opposition on October 9 when it will be at its brightest, magnitude 7.9. It will then be just under 1.75° from the star θ Cet, magnitude 3.6. After opposition Melpomene will continue to move in a south westerly direction, reaching its most southerly declination on November 7. Ten days later it is again stationary before starting to move to the northeast.

The distance of Melpomene from the Sun varies between 1.79 and 2.80 AU. At its closest to the Earth the two are 0.81 AU apart. These are the conditions at the 2009 opposition, Melpomene is at perihelion, its closest to the Sun, two days after opposition. As a result, at the 2009 opposition the asteroid will be as bright as it can be as seen from the Earth.

Melpomene is a fairly large asteroid with a diameter of 141 km. Its orbital period is 3.48 years, the orbit being inclined at 10.1° to the ecliptic. It was discovered in 1852 on June 24 by J R Hind in London.