Student Profile: Ben Pope

What was my project about?

Ben Pope

Ben Pope

At Sydney I worked with Professor Peter Tuthill on a new image analysis paradigm called kernel phase interferometry. Inspired by the 'closure-phase' technique, whereby most of a telescope aperture is blocked off apart from a pattern of holes, which then allows you to construct 'closure phases' which are observables with very high signal-to-noise, Dr Frantz Martinache generalized these mathematics to an arbitrary telescope pupil and greatly increased its applicability. This new technique can construct self-calibrating, closure-phase like quantities from redundant adaptive optics (AO)-corrected apertures. Using this, we are able to achieve high angular resolution, high-contrast detection of faint companions to stars using the Hubble Space Telescope and the Palomar 200 Inch. I visited Subaru Telescope in Hilo, Hawai'i from 17 June to 28 July 2012 to work with Martinache developing kernel phase code and exploring its applications.

Phase graph

results with kernel complement wavefront sensing where we successfully corrected aberrations on a JWST mockup using only the image, to a degree that was indistinguishable from the diffraction limit. Videos can be seen here

What I enjoyed about research.

It was a perfect project - helping develop new ideas,
intensive software development, working with two of the world's most advanced telescopes and discovering a collection of brown dwarfs and even planet candidates that had been missed in previous studies. This led to international travel, and acceptance into a DPhil in Oxford - as well as breaking the ground for a generalization of kernel phase, kernel complement wavefront sensing, which we have been testing on the Palomar 200 Inch AO system and which might eventually be used on the James Webb Space Telescope, the successor to Hubble. Most importantly, I had a terrific supervisor and great friends in the department, and have fond memories of trips to Thai Square, St Germain Patisserie and the Tech Park Hotel with a great bunch of people.

Publications and Media Articles

Ben won the coveted Bok Prize for this research, more detail can be found in Ben Pope Wins Coveted Bok Prize and Breathing new life into astronomical images.

Dancing in the dark: New brown dwarf binaries from kernel phase interferometry.
A demonstration of wavefront sensing and mirror phasing from the image domain.
Interferometric radii of bright Kepler stars with the CHARA Array.