David Baker
A5065115704- Astro and Planetary Science
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Planetary Science and Exploration
- Meteorological Phenomena and Simulations
- Climate variability and models
- Astrophysics and Star Formation Studies
- Space Exploration and Technology
- Plant Water Relations and Carbon Dynamics
- Tropical and Extratropical Cyclones Research
- Space Science and Extraterrestrial Life
- Spaceflight effects on biology
- Astronomical Observations and Instrumentation
- Atmospheric Ozone and Climate
- Science and Climate Studies
- Spectroscopy and Laser Applications
- Space exploration and regulation
- Geomagnetism and Paleomagnetism Studies
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- Aviation History and Innovations
- Electromagnetic Launch and Propulsion Technology
- Quality and Safety in Healthcare
- Flood Risk Assessment and Management
- Aeolian processes and effects
Austin College
2004-2024
Montefiore Medical Center
2021-2022
University of Hertfordshire
2011-2015
Universities Space Research Association
1998-2001
University of Maryland, Baltimore County
2000-2001
University of California, Los Angeles
1992-2000
Goddard Space Flight Center
1998-1999
Earth and Space Research
1992
Martin Marietta Materials (United States)
1990
We report the discovery of 76 new T dwarfs from UKIDSS Large Area Survey (LAS). Near-infrared broad and narrow-band photometry spectroscopy are presented for objects, along with WISE warm-Spitzer photometry. Proper motions 128 a two epoch LAS proper motion catalogue. use these to identify benchmark systems: LHS 6176AB, T8+M4 pair HD118865AB, T5.5+F8 pair. Using age constraints primaries evolutionary models constrain radii we have estimated their physical properties bolometric luminosity....
We present the discovery of TOI-197.01, first transiting planet identified by Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology host star is possible. TOI-197 (HIP116158) a bright (V=8.2 mag), spectroscopically classified subgiant oscillates with an average frequency about 430 muHz and displays clear signature mixed modes. The oscillation amplitude confirms that redder TESS bandpass compared to Kepler has small effect on oscillations, supporting expected yield thousands...
Abstract JWST has ushered in an era of unprecedented ability to characterize exoplanetary atmospheres. While there are over 5000 confirmed planets, more than 4000 Transiting Exoplanet Survey Satellite (TESS) planet candidates still unconfirmed and many the best planets for atmospheric characterization may remain be identified. We present a sample TESS that we identify as “best-in-class” transmission emission spectroscopy with JWST. These targets sorted into bins across equilibrium...
Idealized numerical simulations of Florida convection are performed with a coupled atmosphere–land surface model to identify the roles initial soil moisture, coastline curvature, and land-breeze circulations on sea-breeze-initiated precipitation. The 3D Goddard Cumulus Ensemble cloud-resolving is Parameterization for Land–Atmosphere–Cloud Exchange land model, thus providing tool simulate more realistically surface–atmosphere interaction convective initiation. Eight conducted either straight...
Abstract Astronomers do not have a complete picture of the effects wide-binary companions (semimajor axes greater than 100 au) on formation and evolution exoplanets. We investigate these using new data from Gaia Early Data Release 3 Transiting Exoplanet Survey Satellite mission to characterize systems with transiting identify sample 67 exoplanet candidates (with well-determined, edge-on orbital inclinations) that reside in wide visual binary systems. derive limits parameters for measure...
Abstract We present the discovery and characterization of five hot warm Jupiters—TOI-628 b (TIC 281408474; HD 288842), TOI-640 147977348), TOI-1333 395171208, BD+47 3521A), TOI-1478 409794137), TOI-1601 139375960)—based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The planets were identified full-frame images confirmed through a series photometric spectroscopic follow-up observations by TESS Follow-up Observing Program Working Group. are all Jovian size ( R P = 1.01–1.77...
The TESS mission is searching for transiting planets over the entire sky, including two continuous viewing zones. Data from zones span a long time baseline and offer ideal conditions precise planet radius estimations, enabling community to prepare PLATO mission. We report on validation characterisation of around TOI-1453, K-dwarf star in northern zone. In addition data, we used ground-based photometric, spectroscopic, high-resolution imaging follow-up observations validate planets. obtained...
Abstract The Kilodegree Extremely Little Telescope (KELT) project has been conducting a photometric survey of transiting planets orbiting bright stars for over 10 years. KELT images have pixel scale ∼23″ −1 —very similar to that NASA’s Transiting Exoplanet Survey Satellite ( TESS )—as well as large point-spread function, and the reduction pipeline uses weighted aperture with radius 3′. At this angular scale, multiple are typically blended in apertures. In order identify false positives...
The James Webb Space Telescope (JWST) will be able to probe the atmospheres and surface properties of hot, terrestrial planets via emission spectroscopy. We identify 18 potentially planet candidates detected by Transiting Exoplanet Survey Satellite (TESS) that would make ideal targets for these observations. These cover a broad range radii ($R_{\rm p} \sim 0.6 - 2.0 R_\oplus$) orbit stars various magnitudes ($K_s = 5.78 10.78$, $V 8.4 15.69$) effective temperatures ($T_{\rm eff }\sim 3000...
Abstract We present the discovery of TOI-1518b—an ultra-hot Jupiter orbiting a bright star ( V = 8.95). The transiting planet is confirmed using high-resolution optical transmission spectra from EXPRES. It inflated, with R p 1.875 ± 0.053 J , and exhibits several interesting properties, including misaligned orbit <?CDATA ${240.34}_{-0.98}^{+0.93}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>240.34</mml:mn> </mml:mrow>...
This paper is the second of a two-part study that numerically investigates internal gravity wave generation by convection in lower atmosphere Venus. Part I this considers and propagation absence mean wind shear. In II, Venus westward superrotation included, wave–mean flow interaction assessed. Both lower-atmosphere cloud-level play active roles dynamics stable layer from 31- to 47-km altitude when shear present. result contrasts with simulation without presented where was primarily...
The 65–72 latitude band of the North Polar Region Mars, where 2007 Phoenix Mars Lander will land, was studied using satellite images from Global Surveyor (MGS) Orbiter Camera Narrow‐Angle (MOC‐NA) camera. Dust devil tracks (DDT) and wind streaks (WS) were observed recorded as surface evidence for winds. No active dust devils (DDs) observed. 162 MOC‐NA images, 10.3% total contained DDT/WS. landing C (295–315W) had highest concentration containing DDT/WS per number available (20.9%); D...
Multi-planet systems are valuable arenas for investigating exoplanet architectures and comparing planetary siblings. TOI-1246 is one such system, with a moderately bright K dwarf ($\rm{V=11.6,~K=9.9}$) four transiting sub-Neptunes identified by TESS orbital periods of $4.31~\rm{d},~5.90~\rm{d},~18.66~\rm{d}$, $~37.92~\rm{d}$. We collected 130 radial velocity observations Keck/HIRES TNG/HARPS-N to measure planet masses. refit the 14 sectors photometry refine radii ($\rm{2.97 \pm...
A two-dimensional, nonlinear, fully compressible model of a perfect gas is used to simulate cloud-level penetrative convection in the Venus atmosphere from 40 60 km altitude. Three cases with different amounts solar heating are considered: 60%, 80%, and 100% subsolar conditions corresponding maximum internally heated Rayleigh numbers 4.0 × 106, 5.4 6.8 respectively. Cloud-level characterized by cold, narrow downwellings that deeply penetrate (∼5 km) underlying stable layer. The horizontal...
We have carried out a search for late-type T dwarfs in the UKIDSS Galactic Plane Survey 6th Data Release. The yielded two persuasive candidates, both of which been confirmed as dwarfs. brightest, UGPS J0521+3640 has assigned spectral type T8.5 and appears to lie at distance 7-9 pc. fainter two, J0652+0324, is classified T5.5 dwarf, lies an estimated 28-37 Warm-Spitzer observations IRAC channels 1 2, taken part GLIMPSE360 Legacy Survey, are available we used these data with near-infrared...
Abstract This study used a two-dimensional coupled land–atmosphere (cloud resolving) model to investigate the influence of land cover on water budgets convective lines in West Africa. Study simulations same initial sounding and one three different covers: sparsely vegetated semidesert, grassy savanna, dense evergreen broadleaf forest. All began at midnight ran for 24 h capture full diurnal cycle. During morning, forest had highest latent heat flux, shallowest, moistest, slowest growing...
This paper is the first of a two-part study that investigates internal gravity wave generation by convection in lower atmosphere Venus. A two-dimensional, nonlinear, fully compressible model perfect gas employed. The calculations consider from 12- to 60-km altitude, thereby including two regions: layer roughly 18- 30-km altitude and cloud-level 48- 55-km altitude. waves interest are located stable between these regions. Part I this considers propagation absence mean wind shear. In shear,...
Three major modifications to the treatment of land surface processes in Pennsylvania State University–National Center for Atmospheric Research mesoscale model MM5, are tested a matrix eight experiments. Paired together each dimension versions code with and without one changes. The three changes involve 1) sophisticated [the Parameterization Land–Atmosphere Convective Exchange (PLACE)], 2) soil moisture temperature initial conditions derived from running PLACE offline, 3) 1.5-order turbulent...
We present the discovery of 49 new photometrically classified T dwarfs from combination large infrared and optical surveys combined with follow-up TNG photometry. used multi-band photometry UKIRT Sloan Digital Sky Surveys to identify possible brown dwarf candidates, which were then confirmed using methane filter have defined a photometric conversion between CH4s - CH4l colour spectral type for T4 T8 based on part sample that has been followed up spectroscopy. Using differential as proxy...
We present the discovery of two new transiting extrasolar planet candidates identified as TOI-1296.01 and TOI-1298.01 by Transiting Exoplanet Survey Satellite (TESS). The planetary nature these has been secured with SOPHIE high-precision spectrograph through measurement companion's mass radial velocity method. Both planets are similar to Saturn in have orbital periods a few days. They, however, show discrepant radii therefore different densities. radius discrepancy might be explained levels...
Two transiting planet candidates with super-Earth radii around the nearby K7--M0 dwarf star TOI-1238 were announced by TESS. We aim to validate their planetary nature using precise radial velocities (RV) taken CARMENES spectrograph. obtained 55 RV data that span 11 months. For a better characterization of parent star's activity, we also collected contemporaneous optical photometric observations and retrieved archival photometry from literature. performed combined TESS+CARMENES spectroscopic...
Numerical simulations of two‐dimensional, nonlinear fully compressible convection at the subsolar point in clouds Venus are presented. One moderate Rayleigh number case ( Ra q = 6.8 × 10 6 ) and two high 1.1 9 cases considered. Cloud‐level is characterized by cold, narrow downwellings that deeply penetrate underlying stable layer entrain warmer air from overlying layer. The depth, as determined horizontally averaged static stability, spans km (47–56 altitude) 14 (46–60 for simulations,...
Through collaborative and individual projects in two upper level courses, undergraduate students established a new surface environmental observation station (Austin College Weather Station). In addition to standard meteorological observations, the Austin Station detects radiation soil measurements. These additional measurements are used calculate local energy balance, an important indicator of climate system interactions.The weather provided excellent opportunities for participate actively...