Dwarf Planets on the Move
by Jim Mazur
There are currently five objects classified as dwarf planets in the solar system: Ceres, Pluto, Eris, Makemake, and Haumea. Below are images of three of them, showing their movement by blinking images taken on two different nights. They may not be easy to spot, but look for the moving object near the center of each image.
Pluto. The movement of Pluto over a 48-hour period is shown against the rich Milky Way background stars in Sagittarius. It is moving up and down, near the very center of this image. Taken with a 12-inch Meade LX200 telescope and an SBIG ST8300M imager, September 20-22, 2013.
Eris. About 9 billion miles from the Sun, Eris is the most distant dwarf planet known, roughly three times as far away as Pluto. It is the very dim moving point of light (about magnitude 18.7) that is roughly halfway between the brightest star in this image and the small galaxy to its lower right. Taken with a 12-inch Meade LX200 telescope and an SBIG ST8300M imager, September 27-28, 2013.
Haumea. Haumea is smaller than Pluto, and it is slightly farther away. Its shape is not round but elliptical. These two images were taken three nights apart. In the first, Haumea is just to the lower right of the bright star in the center of the picture. In the image taken three nights later, Haumea has moved toward the lower left, but still not far from the center. Taken with a 14-inch Meade LX850 telescope and an SBIG ST8300M imager, August 26-29, 2016.