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Australian Human Resources Institute Diversity Awards 2013 Finalist

Paul Butler (Carnegie Observatories)

"Exoplanets searches with PFS and APF"

Abstract. Modern science began with Copernicus speculating that the Earth is a planet and that all the planets orbit the Sun. Bruno followed up by speculating that the Sun is a star, that other stars have planets, and other planets are inhabited by life. For this and other heresies, Bruno was burned at the stake in a public square in Rome in 1600. Astronomy and extrasolar planets were a really hot field at the time.

Over the past 20 years more than a thousand extrasolar planets have been found, first from ground-based precision Doppler and photometric transit surveys, and more recently by the Kepler space mission. We have concentrated on building precise Doppler systems to survey the nearest stars. Our systems at Lick, Keck, AAT, and Magellan have found hundreds of planets, including 5 of the first six planets, the first saturn-mass planet, the first neptune-mass planet, the first terrestrial mass planet, and the first multiple planet system.

We are currently focusing our attention on new custom built "R4" echelle spectrometers designed for Iodine cells, which are yielding 1 m/s precision. These spectrometers have a footprint about the size of a ping pong table, allowing for temperature stabilization, yet deliver higher resolution and dispersion than the much larger classic echelle spectometers, such as the Lick Hamilton, the AAT UCLES, and the Keck HIRES. The two working examples, PFS on the 6.5-m Magellan, and the Levy spectrometer on the 2.4-m APF, cost about US$2M each. They do not use fibers or scrambling, and have throughput of 20 to 30%, a factor of 2 to 4 better than classic echelles. These spectrometer will lead to the discovery of many terrestrial mass and potentially habitable planets over the next decade.

Held in the AAO Meeting Room (Room 7, 1st Floor, Building 2) at 11:00 AM on Thursday, 20 March 2014