Potential research projects

Automated detection of transients in all-sky camera images (Honours project)

Comet and Asteroid Photometry (Honours project)

The basic objective is to monitor the variation in brightness of at least one newly-discovered comet and an asteroid in order to determine their rotation periods. Also, a comet and asteroid of known rotation rates should also be monitored to check the analysis procedures.

Comets are dusty snowballs and members of our Solar System. Typically, they have elongated orbits around our Sun. They are important objects to study because they are remnant material left over from the formation of the Solar System.

Studies of the reflected sunlight from these objects reveal many of their properties. Spectroscopic studies reveal molecules that were present at the formation of the Solar System, as well as others that are created during the heating that ensues during close passages past the Sun. Cometary nuclei are difficult to study because they are usually obscured by a very large and relatively bright coma of dust. However, periodic brightness variations have been detected for several cometary nuclei (Crovisier & Encrenaz, 2000, and references therein). These have been interpreted as the rotation period of these nuclei and this reveals information about the bulk properties of this material. However, these results are not universally accepted as being legitimate studies of the nuclei alone – other processes can occur that corrupt straightforward interpretation.

Asteroids are important objects to study because they are also remnants of material left over from the formation of the Solar System. Collisions between asteroids are believed to be important in the evolution of their orbital and rotational motion, and the formation of meteoritic material. In general, smaller asteroids rotate faster than larger ones.

Studies of the reflected sunlight from these objects reveal many of their properties. Spectroscopic studies suggest that there are different classes of asteroids with different proportions of stone, metal and carbonaceous material. These classes are linked to the different known types of meteorites and suggest that asteroids are the parent bodies.

Also, the smaller asteroids are not very circular in shape and hence their rotation period can be determined "simply" from monitoring the variations in their brightness. Analysis of rotational periods provides information on the asteroids shapes and/or their collisional history.

Astronomical Site Testing (Honours project)

The basic objective is to make measurements of seeing with a Differential Image Motion Monitor (DIMM) at the Perth Observatory. The measurements are to be undertaken at ground level, on the viewing platforms around the telescope enclosures and within the enclosures themselves. This will enable a comparison of effects near ground level and above it, as well as determining the effect of the enclosure (which may inhibit thermal equilibrium). Weather conditions will also be recorded in order to determine the influence of these on seeing. Another factor explored will be the dependence on azimuth since there is some anecdotal evidence that seeing deteriorates for lines of sight over Perth (west).

A DIMM is a rather straightforward system used to measure seeing and is independent of the aperture of the telescope (eg Wood et al 1995). Perth Observatory has recently constructed such a system. Another Australian group has published their seeing results and this work will facilitate comparisons with other sites in Australia.

Astronomical seeing is a fundamental quality of a site for an optical telescope. It depends on many factors but primarily meteorological conditions. Other important factors are altitude, the aperture of the telescope and how well the instrument is in thermal equilibrium with the surrounding external air. Seeing, is in a sense, a measure of resolution as it can be measured by the Full Width at Half Maximum of star images recorded at a facility. The smaller this measure, the better the seeing and the better the site.

To date, very few quantitative seeing measurements exist for astronomical sites in Western Australia.