This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.

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We report the discovery of a third planetary mass companion to the G0 star HD 74156. High precision radial velocity measurements made with the Hobby-Eberly Telescope aided the detection of this object. The best fit triple Keplerian model to all the available velocity data yields an orbital period of 347 days and minimum mass of 0.4 M Jup for the new planet. We determine revised orbital periods of 51.7 and 2477 days, and minimum masses of 1.9 and 8.0 M Jup respectively for the previously known planets. Preliminary calculations indicate that the derived orbits are stable, although all three planets have significant orbital eccentricities (e = 0.64, 0.43, and 0.25). With our detection, HD 74156 becomes the eighth normal star known to host three or more planets. Further study of this system's dynamical characteristics will likely give important insight to planet formation and evolutionary processes.

We use Hubble Space Telescope Fine Guidance Sensor astrometry and highcadence radial velocities for HD 136118 from the HET with archival data from Lick to determine the complete set of orbital parameters for HD 136118 b. We find an orbital inclination for the candidate exoplanet of i b = 163.1 • ± 3.0 • . This establishes the actual mass of the object, M b = 42 +11 −18 M J , in contrast to the minimum mass determined from the radial velocity data only, M b sin i ∼ 12 M J . Therefore, the low-mass companion to HD 136118 is now identified as a likely brown dwarf residing in the "brown dwarf desert".

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