At present, members of the Remote Planets Section are engaged in the following activities:

Color and Brightness Measurement:

Here, the observer’s goal is to determine seasonal changes in the color and brightness of these planets.

Data taken from 1991-2001 show that Uranus became about 0.003 magnitudes per year dimmer whereas Neptune became 0.01 magnitudes per year brighter. Over 1300 photoelectric measurements have been collected since 1989.

Spectra of Uranus and Neptune:

We are seeking to determine if the spectra of Uranus and Neptune change from one year to the next year. About 6 spectra have been obtained from 1998-2001, and there are no large differences.

Relative brightness of Titania and Oberon:

An attempt is being made to determine if these two moons change in brightness as their sub-Earth latitudes change. Titania is about 0.2 magnitudes brighter than Oberon; it is too early to tell if the relative brightness changes with the sub-Earth latitude; about 20 brightness measurements have been made since 1996.

Occultation of stars by the remote planets and their satellites:

This study gives us valuable clues to the natures of the atmospheres of the remote planets and their satellites. The Titania occultation of Sep. 8, 2002 was measured by Antonio Cidadao. His results show that Titania has a surface atmospheric pressure of no more than 1.0 microbar. Only one occultation has been successfully observed.

Polarization studies:

We are measuring the polarization curves of the remote planets and their satellites as a function of solar phase angle. Data for this project will be collected starting in 2002.