Search Publications
Probing the extreme planetary atmosphere of WASP-12b
Showman, Adam P.; Swain, Mark; Kawahara, Hajime +7 more
We report near-infrared measurements of the terminator region transmission spectrum and dayside emission spectrum of the exoplanet WASP-12b obtained using the HST WFC3 instrument. The disk-average dayside brightness temperature averages about 2900 K, peaking to 3200 K around 1.46 µm. We modeled a range of atmospheric cases for both the emiss…
The escape of heavy atoms from the ionosphere of HD209458b. II. Interpretation of the observations
Yelle, R. V.; Lavvas, P.; Koskinen, T. T. +1 more
Transits in the H I 1216 Å (Lyman α), O I 1334 Å, C II 1335 Å, and Si III 1206.5 Å lines constrain the properties of the upper atmosphere of HD209458b. In addition to probing the temperature and density profiles in the thermosphere, they have implications for the properties of the lower atmosphere. Fits to the observations with a simple empirical …
Photometric properties of the nucleus of Comet 103P/Hartley 2
A'Hearn, Michael F.; Thomas, Peter C.; Bodewits, Dennis +8 more
We have studied the photometric properties of the nucleus of a hyperactive comet, 103P/Hartley 2, at visible wavelengths using the DIXI flyby images with both disk-integrated and disk-resolved analyses. The disk-integrated phase function of the nucleus has a linear slope of 0.046 ± 0.002 mag/deg and an absolute magnitude of 18.4 ± 0.1 at V-band. T…
Near-infrared spectral monitoring of Pluto's ices: Spatial distribution and secular evolution
Olkin, C. B.; Buie, M. W.; Young, E. F. +2 more
We report results from monitoring Pluto's 0.8 to 2.4 µm reflectance spectrum with IRTF/SpeX on 65 nights over the dozen years from 2001 to 2012. The spectra show vibrational absorption features of simple molecules CH4, CO, and N2 condensed as ices on Pluto's surface. These absorptions are modulated by the planet's 6.39 …
Comparing Dawn, Hubble Space Telescope, and ground-based interpretations of (4) Vesta
Nathues, Andreas; Russell, Christopher T.; Li, Jian-Yang +10 more
Observations of Asteroid (4) Vesta by NASA’s Dawn spacecraft are interesting because its surface has the largest range of albedo, color and composition of any other asteroid visited by spacecraft to date. These hemispherical and rotational variations in surface brightness and composition have been attributed to impact processes since Vesta’s forma…
Synergistic observations of Io’s atmosphere in 2010 from HST-COS in the mid-ultraviolet and IRTF-TEXES in the mid-infrared
Tsang, Constantine C. C.; Spencer, John R.; Jessup, Kandis Lea
We report on mid-UV spectroscopy of Io’s SO2 atmosphere from the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST), and compare to contemporaneous ground-based mid-infrared spectroscopy of the atmosphere. Our motivation is to evaluate the consistency of atmospheric parameters derived by different observational techni…
Hubble observations of Jupiter’s north-south conjugate ultraviolet aurora
Bonfond, B.; Clarke, J. T.; Gérard, J. -C. +2 more
Comparisons of the northern and southern far ultraviolet (UV) auroral emissions of Jupiter from the Hubble Space Telescope (HST) or any other ultraviolet imager have mostly been made so far on a statistical basis or were not obtained with high sensitivity and resolution. Such observations are important to discriminate between different mechanisms …
A 3D general circulation model for Pluto and Triton with fixed volatile abundance and simplified surface forcing
Michaels, Timothy I.; Zalucha, Angela M.
We present a 3D general circulation model of Pluto and Triton's atmospheres, which uses radiative-conductive-convective forcing. In both the Pluto and Triton models, an easterly (prograde) jet is present at the equator with a maximum magnitude of 10-12 m s-1 and 4 m s-1, respectively. Neither atmosphere shows any significant …
Jupiter's Great Red Spot: Fine-scale matches of model vorticity patterns to prevailing cloud patterns
Dowling, Timothy E.; Morales-Juberías, Raúl
We report on a set of six new matches between fine-scale features in the vorticity field of a three-dimensional (3D), primitive-equation, finite-difference model of Jupiter's Great Red Spot that includes no clouds or cloud physics, and quasi-permanent structures in reflected visible-band images of the clouds. These add to similar success by Cho et…
An updated rotation model for Comet 9P/Tempel 1
Li, J. -Y.; Harris, A. W.; Veverka, J. +8 more
Observations from the second encounter of Comet 9P/Tempel 1 by the Stardust-NExT spacecraft provide an improved shape model and rotational pole for the nucleus (Thomas, P.C. et al. [2012]. Icarus 222, 453-466) that allows us to greatly improve our knowledge of its rotational evolution beyond that outlined earlier in Belton et al. (Belton, M.J.S. e…