Doppler Searches for Extrasolar Planets, Brown dwarfs.
Field of Research (FoR)
I head the Exoplanetary Science at UNSW research group within the Australian Centre for Astrobiology, in the School of Physics. My research interests are centered on “exoplanets” (planets that orbit other stars), as well as the very cool low-mass “star-like” bodies known as brown dwarfs (which share many properties with exoplanets). The study of both these classes of object tell us how stars and planets form and...view more
I head the Exoplanetary Science at UNSW research group within the Australian Centre for Astrobiology, in the School of Physics. My research interests are centered on “exoplanets” (planets that orbit other stars), as well as the very cool low-mass “star-like” bodies known as brown dwarfs (which share many properties with exoplanets). The study of both these classes of object tell us how stars and planets form and evolve, which is key to understanding how prevalent habitable environments are near the Sun, throughout the Galaxy and elsewhere in the Universe. I have worked at Observatories and Universities in Australia, Europe and the USA, and carry out my research with in concert with collaborators across Australia, Europe, the UK, USA and Chile.
PhD in Astronomy (California Institute of Technology, 1992)
BSC Hons in Physics (University of Sydney, 1987)
My Research Goals
- Discovery and Study of Exoplanets
- Discovery and Study of very cool “Brown Dwarfs”
- Using the properties of these classes of objects to inform our uderstanding of how stars and planets form
- Combining all this data to understand how prevalent habitable environments are in the Universe
My Research in Detail
My group currently hosts two faculty, four post-doctoral researchers and four graduate students, working on projects ranging from
- the search for exoplanets orbiting Sun-like main sequence stars (the Anglo-Australian Planet Search),
- the search for exoplanets around evolved stars more massive than the Sun (Rob Wittenmyer's Southern Sub-Giant Planet Search),
- direct imaging observations of already known long-period companions to Anglo-Australian Planet Search stars, follow-up of transit candidates from the HAT-South planet search,
- detailed studies of transiting planets to determine the alignment of their orbit with their host-star’s rotation axis,
- direct imaging searches of both aligned and misaligned systems to investigate whether binary companions are the cause of these misalignments,
- searches for low-mass planets in the habitable zones of nearby M dwarf stars (with Duncan Wright), and
- discovering and studying the coolest Y-type brown dwarfs in the Solar Neighbourhood using data from NASA's WISE satellite.
We are also actively pursuing new technologies for searching for exoplanets - especially the use of image slicing fibre technologies for improving spectrograph performance, the use of fibre technologies for removing spatial information from the entrance apertures of astronomical spectrographs, and for smashing the current cost-paradigms for high-resolution spectrographs on large aperture telescopes.
We are in the process of constructing a new high-resolution spectrograph for the Anglo-Australian Telescope. This concept, which we call Veloce, would use image slicing and an innovative asymmetric white pupil design to deliver an extremely cost-effective high-resolution facility, enabling world-leading Doppler spectroscopy on the AAT well into the next decade, as well as replacing and upgrading the facilities offered by the current UCLES spectrograph on the AAT.
We are also pursuing the FunnelWeb survey concept, together with researchers at Macquarie University and across Australia. This survey would deliver spectroscopy for all ~2 million stars brighter than V=12 that are visible from the Southern hemisphere - providing a gold-mine of information on the locations of the youngest stars (for use as targets in direct imaging exoplanet searches), binary and eclipsing binary stars, potential targets for NASA's TESS satellite ... and a wealth of other killer science.
We work closely with colleagues within the Australian Centre for Astrobiology to examine the impacts of our exoplanetary discoveries on the question of habitable environments outside the Solar System - especially with the members of Prof. Jeremy Bailey's Planetary Science group, here within the Astrophysics Department.
Current Student Projects (PhD and Honours)
- Measuring spin-orbit misalignments of transiting planet systems using the Rossiter-McLaughlin effect (PhD).
- Using the huge library of high-Signal-to-Noise-ratio spectra of Sun-like stars acquired by the Anglo-Australian Planet Search to carry out previously impossible studies of weak metal-lines, and/or searches for variability in stronger lines (Hons/PhD)
- Using the Gemini telescope’s new Multi-Conjugate Adaptive Optics instrument GeMS to carry out the first systematic exploration of the use of Adaptive Optics for astrometry – and in the process measuring distances to planetary-mass brown dwarfs with 300-400K temperatures, as well as searching these systems for binary companions (PhD)
- Searching for Wide-separation Companions to the Coolest Brown Dwarfs, by using data (acquired on the Magellan 6.5m telescope in Chile) to look for other objects in the field of view that share a common motion across the sky with the planetary-mass brown dwarfs we are studying (Hons)
- Exploring the WISE database to identify new and (previously unknown) very cold brown dwarfs near the Sun (Hons)
- Parallaxes for L-type Brown Dwarfs using 4 years of data acquired at the AAT with the WFI camera of a sample of nearby L- dwarfs selected from the 2MASS all-sky survey.
In addition to the specific projects listed above, there exists substantial scope for projects based on the broad research areas being pursued in our group (see above). Some of these projects will be more targeted at observations, others at simulations, and others at heavy-duty data analysis. An ideal thesis project will contain aspects of all these, but the projects can be tuned to suit the specific skills and interests of students.
Advice for prospective students
The most important advice I always give to students is “choose the supervisor – not the project”. A research project will engage much of your attention for a substantial period of time. And that works best if you get on with the people you work with. So talk to different potential supervisors, and their students and their post-docs and their colleagues. Then decide what you want to do based on how well you think you’ll work in those teams.
I consider my job as a researcher to be about the best job one could possibly have – every day there is the possibility I will discover something about the Universe that no one has ever known before. And I get to do that with clever, motivated and exciting colleagues on some of the world’s largest optical/infrared telescopes.
If you are excited by the idea of discovering other worlds, and then exploring their properties using detailed observations on telescopes spread around the world, then get in touch!
TEACHING & OUTREACH
Courses I teach
Professional affiliations and service positions
I am Associate Dean (Research) with the UNSW Faculty of Science.
I am Co-Director of the Australian Centre for Astrobiology here at UNSW.
I am Chair of the Optical Telescopes Advisory Committee of Astronomy Australia Limited.
I am member of the Giant Magellan Telescope project’s Science Advisory Committee.
I am a Fellow of the Astronomical Society of Australia, and a member of the American Astronomical Association and the International Astronomical Union.
AWARDS & ACHIEVEMENTS
2013 NSW Science and Engineering Award for Excellence in Mathematics, Earth Science, Chemistry and Physics
2013 Australian Research Council Discovery Outstanding Researcher
2012 26th Harley Wood Lecturer of the Astronomical Society of Australia
2007 Australian Research Council Australian Professorial Fellow
2002 Australian Engineering Excellence Award, Institution of Engineers, Australia for the IRIS2 instrument