Search for Kuiper Belt Binaries using Centre of Light Oscillations


Located beyond planet Neptune, the Kuiper Belt holds numerous icy bodies which are relics of the formation of the planets. These Kuiper Belt objects (KBOs) act as an archaeological resource from which we can gain an understanding of how the Solar System was born and what specific processes gave rise to the variety of the observed planets, comets and asteroids in the last 4.5 billion years.

A large fraction of KBOs are found in stable binary pairs, or binaries. Since binaries are not being replenished today, the fact that so many exist is a strong indication that all KBOs were born in binaries. Importantly, without in-situ measurements from spacecraft, binaries act as the only window through which remote sensing can reveal the mass and density of the KBOs.

KBO binaries were for the most part discovered through high resolution imaging, resolving both components separately. To increase the sample of known binaries we have to come up with other strategies.


Even if we lack the resolution to separate the two components of a binary, we might be able to detect the slight wobble in the pair’s centre-of-light, as the two bodies orbit their mutual centre of mass. This requires very accurate tracing of the trajectory of the light against the background stars. Two powerful sky surveys, the PanSTARRS PS1 survey and the GAIA survey, have recently supplied the reference dataset that will enable this idea.

The start of the project will thus consist of matching a very large number of images of KBOs against the two survey catalogues with the goal of determining the centre-of-light trajectory against the stars with unprecedented accuracy and search for the presence of unseen binaries. Successful detections can be followed up using other telescopes for further characterisation and interpretation.


The student should develop a range of skills that are highly valued in science and in industry. These will including image processing, advanced numerical, statistical modelling, and preparation and presentation of written and oral reports.

More info

Supervisors: For further information, please contact Dr Pedro Lacerda and Dr Wes Fraser.

public/phds2017/2017_lacerda.txt · Last modified: 2017/01/17 10:34 by Pedro Lacerda

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