Search Publications
An HST/WFC3 Thermal Emission Spectrum of the Hot Jupiter HAT-P-7b
Fortney, Jonathan J.; Stevenson, Kevin B.; Désert, Jean-Michel +7 more
Secondary eclipse observations of several of the hottest hot Jupiters show featureless, blackbody-like spectra or molecular emission features, which are consistent with thermal inversions being present in those atmospheres. Theory predicts a transition between warmer atmospheres with thermal inversions and cooler atmospheres without inversions, bu…
Cepheid Abundances: Multiphase Results and Spatial Gradients
Luck, R. Earle
Parameters and abundances have been derived for 435 Cepheids based on an analysis of 1127 spectra. Results from five or more phases are available for 52 of the program stars. The latter set of stars span periods between 1.5 and 68 days. The parameters and abundances show excellent consistency across phase. For iron, the average range in the determ…
Kinematics of Highly r-process-enhanced Field Stars: Evidence for an Accretion Origin and Detection of Several Groups from Disrupted Satellites
Hattori, Kohei; Roederer, Ian U.; Valluri, Monica
We present the kinematics of 35 highly r-process-enhanced ([Eu/Fe] ≥ +0.7) metal-poor (-3.8 < [Fe/H] < -1.4) field stars. We calculate six-dimensional positions and velocities, evaluate energies and integrals of motion, and compute orbits for each of these stars using parallaxes and proper motions from the second Gaia data release and publis…
WFIRST Exoplanet Mass-measurement Method Finds a Planetary Mass of 39 ± 8 M ⊕ for OGLE-2012-BLG-0950Lb
Bennett, D. P.; Udalski, A.; Anderson, J. +13 more
We present the analysis of the simultaneous high-resolution images from the Hubble Space Telescope and Keck adaptive optics system of the planetary event OGLE-2012-BLG-0950 that determine that the system consists of a 0.58 ± 0.04 {M}⊙ host star orbited by a 39 ± 8 {M}\oplus planet at a projected separation of 2.54 ± 0.23 au…
Time-resolved WISE/NEOWISE Coadds
Lang, D.; Meisner, A. M.; Schlegel, D. J.
We have used the first ∼3 years of 3.4 µm (W1) and 4.6 µm (W2) observations from the WISE and NEOWISE missions to create a full-sky set of time-resolved coadds. As a result of the WISE survey strategy, a typical sky location is visited every six months and is observed during ≳12 exposures per visit, with these exposures spanning a ∼1 d…
Different Stellar Rotations in the Two Main Sequences of the Young Globular Cluster NGC 1818: The First Direct Spectroscopic Evidence
Milone, A. P.; Marino, A. F.; D'Antona, F. +4 more
We present a spectroscopic analysis of main sequence (MS) stars in the young globular cluster NGC 1818 (age ∼40 Myr) in the Large Magellanic Cloud. Our photometric survey of Magellanic Clouds clusters has revealed that NGC 1818, similar to other young objects with ages ≲600 Myr, displays not only an extended MS turnoff (eMSTO), as observed in inte…
ExoGAN: Retrieving Exoplanetary Atmospheres Using Deep Convolutional Generative Adversarial Networks
Zingales, Tiziano; Waldmann, Ingo P.
Atmospheric retrievals on exoplanets usually involve computationally intensive Bayesian sampling methods. Large parameter spaces and increasingly complex atmospheric models create a computational bottleneck forcing a trade-off between statistical sampling accuracy and model complexity. It is especially true for upcoming JWST and ARIEL observations…
The LEECH Exoplanet Imaging Survey: Limits on Planet Occurrence Rates under Conservative Assumptions
Fortney, Jonathan J.; De Rosa, Robert J.; Weigelt, Gerd +33 more
We present the results of the largest L‧ (3.8 µm) direct imaging survey for exoplanets to date, the Large Binocular Telescope Interferometer Exozodi Exoplanet Common Hunt (LEECH). We observed 98 stars with spectral types from B to M. Cool planets emit a larger share of their flux in L‧ compared to shorter wavelengths, affording LEECH an adva…
Sixty Validated Planets from K2 Campaigns 5-8
Henning, Thomas; Tamura, Motohide; Schlieder, Joshua E. +13 more
We present a uniform analysis of 155 candidates from the second year of NASA’s K2 mission (Campaigns 5-8), yielding 60 statistically validated planets spanning a range of properties with median values of R p = 2.5 {R}\oplus , P = 7.1 days, T eq = 811 K, and J = 11.3 mag. The sample includes 24 planets in 11 mult…
The Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas (MegaSaura). I. The Sample and the Spectra
Dahle, H.; Rigby, J. R.; Bayliss, M. B. +7 more
We introduce Project MEGaSaURA: the Magellan Evolution of Galaxies Spectroscopic and Ultraviolet Reference Atlas. MEGaSaURA comprises medium-resolution, rest-frame ultraviolet spectroscopy of N = 15 bright gravitationally lensed galaxies at redshifts of 1.68 < z < 3.6, obtained with the MagE spectrograph on the Magellan telescopes. The spect…