Robert A. Wittenmyer

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We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new-generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of 63:4 AE 2:0 m s À1 and(More)
We re-analyze 4 years of HARPS spectra of the nearby M1.5 dwarf GJ 667C available through the ESO public archive. The new radial velocity (RV) measurements were obtained using a new data analysis technique that derives the Doppler measurement and other instrumental effects using a least-squares approach. Combining these new 143 measurements with 41(More)
The Anglo-Australian Planet Search has now accumulated 12 years of radial-velocity data with long-term instrumental precision better than 3 m s −1. In this paper, we expand on earlier simulation work, to probe the frequency of near-circular, long-period gas-giant planets residing at orbital distances of 3-6 AU – the so-called " Jupiter analogs. " We present(More)
Determining the occurrence rate of terrestrial-mass planets (m p < 10M ⊕) is a critically important step on the path towards determining the frequency of Earth-like planets (η ⊕), and hence the uniqueness of our Solar system. Current radial-velocity surveys, achieving precisions of 1 m s −1 , are able to detect terrestrial-mass planets and provide(More)
Citation Albrecht, Simon et al. " A high stellar obliquity in the WASP-7 exoplanetary system. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. ABSTRACT We measure a tilt of 86 ± 6 • between the sky projections of the rotation axis of the WASP-7 star, and the orbital axis of its close-in(More)
The Second Workshop on Extreme Precision Radial Velocities defined circa 2015 the state of the art Doppler precision and identified the critical path challenges for reaching 10 cm s −1 measurement precision. The presentations and discussion of key issues for instrumentation and data analysis and the workshop recommendations for achieving this bold precision(More)
The HR 8799 system, with its four giant planets and two debris belts, has an architecture closely mirroring that of our Solar system where the inner, warm asteroid belt and outer, cool Edgeworth-Kuiper belt bracket the giant planets. As such, it is a valuable laboratory for examining exoplanetary dynamics and debris disk-exoplanet interactions. Whilst the(More)
Most stars become white dwarfs after they have exhausted their nuclear fuel (the Sun will be one such). Between one-quarter and one-half of white dwarfs have elements heavier than helium in their atmospheres, even though these elements ought to sink rapidly into the stellar interiors (unless they are occasionally replenished). The abundance ratios of heavy(More)
We report the detection of two planetary mass companions to the solar-type star HD 155358. The two planets have orbital periods of 195.0 and 530.3 days, with eccentricities of 0.11 and 0.18. The minimum masses for these planets are 0.89 and 0.50 M J respectively. The orbits are close enough to each other, and the planets are sufficiently massive, that the(More)