A5022061504- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Atmospheric Ozone and Climate
- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
- Silicone and Siloxane Chemistry
- Astrophysics and Cosmic Phenomena
- Acoustic Wave Resonator Technologies
- Cultural Heritage Management and Preservation
- Optical Systems and Laser Technology
- Galaxies: Formation, Evolution, Phenomena
- Nuclear Physics and Applications
- Aerospace Engineering and Energy Systems
- High-pressure geophysics and materials
- Spacecraft Design and Technology
- Conservation Techniques and Studies
- 3D Surveying and Cultural Heritage
Johns Hopkins University
2022-2024
University of Maryland, College Park
2017-2023
University of Wisconsin–Madison
2016-2018
Institute of Astronomy and Astrophysics, Academia Sinica
2018
Abstract Carbon dioxide (CO 2 ) is a key chemical species that found in wide range of planetary atmospheres. In the context exoplanets, CO an indicator metal enrichment (that is, elements heavier than helium, also called ‘metallicity’) 1–3 , and thus formation processes primary atmospheres hot gas giants 4–6 . It one most promising to detect secondary terrestrial exoplanets 7–9 Previous photometric measurements transiting planets with Spitzer Space Telescope have given hints presence but not...
Planets orbiting M-dwarf stars are prime targets in the search for rocky exoplanet atmospheres. The small size of M dwarfs renders their planets exceptional transmission spectroscopy, facilitating atmospheric characterization. However, it remains unknown whether host stars' highly variable extreme-UV radiation environments allow atmospheres to persist. With JWST, we have begun determine or not most favorable worlds detectable Here, present a 2.8-5.2 micron JWST NIRSpec/G395H spectrum warm...
Abstract We present a JWST/Near Infrared Camera (NIRCam) transmission spectrum from 3.9 to 5.0 μ m of the recently validated sub-Earth GJ 341b ( R P = 0.92 ⊕ , T eq 540 K) orbiting nearby bright M1 star d 10.4 pc, K mag 5.6). use three independent pipelines reduce data JWST visits and perform several tests check for significance an atmosphere. Overall, our analysis does not uncover evidence Our null hypothesis find that none pipelines’ spectra can rule out flat line, although there is weak...
Abstract The search for rocky planet atmospheres with JWST has focused on planets transiting M dwarfs. Such have favorable planet-to-star size ratios, enhancing the amplitude of atmospheric features. Since expected signal strength features is similar to single-transit performance JWST, multiple observations are required confirm any detection. Here, we present two transit GJ 1132 b NIRSpec G395H, covering 2.8–5.2 μ m. Previous Hubble Space Telescope WFC3 were inconclusive, evidence reported...
Abstract JWST is here. The early release observation (ERO) program provides us with the first look at scientific data and spectral capabilities. One of targets from ERO HAT-P-18b, an inflated Saturn-mass planet equilibrium temperature ∼850 K. We present NIRISS/SOSS transmission spectrum HAT-P-18b 0.6 to 2.8 μ m reveal in infrared beyond 1.6 for time. From spectrum, we see clear water escaping helium tail features otherwise very hazy atmosphere. Our free chemistry retrievals ATMO show...
The low-resolution transmission spectra of ultra-hot Jupiters observed shortward 0.5 microns indicate strong absorption at short-wavelengths. Previous explanations have included scattering, photochemistry, escaping metals, and disequilibrium chemistry. In this Letter, we show that slopes features can be caused by opacity not commonly considered in atmosphere models exoplanets but guaranteed to present if conditions are near chemical equilibrium including Fe I, II, Ti Ni Ca SiO. Even...
Common features of sub-Neptunes atmospheres observed to date include signatures aerosols at moderate equilibrium temperatures (~500-800 K), and a prevalence high mean molecular weight atmospheres, perhaps indicating novel classes planets such as water worlds. Here we present 0.83-5 micron JWST transmission spectrum the sub-Neptune TOI-421 b. This planet is unique among previously counterparts in its temperature ($T_{eq} \approx 920$) Sun-like host star. We find marked differences between...
Our brains are hardwired for pattern recognition as correlations useful predicting and understanding nature. As more exoplanet atmospheres being characterized with JWST, we starting to unveil their properties on a population level. Here present framework comparing transmission spectroscopy from 3 5$\mu$m four bands: L (2.9 - 3.7$\mu$m), SO$_2$ (3.95 4.1$\mu$m), CO$_2$ (4.25 4.4$\mu$m) CO (4.5 4.9$\mu$m). Together, the bands cover major carbon, oxygen, nitrogen, sulfur-bearing molecules...
Abstract The Transiting Exoplanet Survey Satellite (TESS) mission identified a potential 0.88 R ⊕ planet with period of 7.577 days, orbiting the nearby M1V star GJ 341 (TOI 741.01). This system has already been observed by James Webb Space Telescope (JWST) to search for presence an atmosphere on this planet. Here, we present in-depth analysis using all available public data. We provide improved parameters host star, updated value radius, and support planetary nature object (now b). use 57...
Abstract Which rocky exoplanets have atmospheres? This presumably simple question is the first that must be answered to understand prevalence of nearby habitable planets. A mere 6.9 pc from Earth, LTT 1445A closest transiting M dwarf system, and its largest known planet, at 1.31 R ⊕ 424 K, one most promising targets in which search for an atmosphere. We use Hubble Space Telescope/Wide Field Camera 3 transmission spectroscopy with G280 G141 grisms study spectrum 1445Ab between 0.2 1.65 μ m....
Abstract We present near-IR imaging polarimetry of five classical FU Ori-type objects (FU Ori, V1057 Cyg, V1515 V1735 Z CMa) with an ∼0.″1 resolution observed using HiCIAO+AO188 at the Subaru Telescope. scattered light associated circumstellar dust around four them (i.e., all but Cyg). Their polarized intensity distribution shows a variety morphologies arms, tails or streams, spikes, and fragmented distributions, many which were reported in our previous paper. The these reflection nebulae...
Transmission spectroscopy provides a window to study exoplanetary atmospheres, but that is fogged by clouds and hazes. Clouds haze introduce degeneracy between the strength of gaseous absorption features planetary physical parameters such as abundances. One way break via statistical studies. We collect all published HST/WFC3 transit spectra for 1.1-1.65 $\mu$m water vapor absorption, perform on potential correlations feature parameters. fit observed with template calculated each planet using...
We present high-resolution dayside thermal emission observations of the exoplanet KELT-20b/MASCARA-2b using MAROON-X spectrograph. Applying cross-correlation method with both empirical and theoretical masks a retrieval analysis, we confirm previous detections Fe\,\textsc{i} lines detect Ni\,\textsc{i} for first time in planet (at 4.7$\sigma$ confidence). do not see evidence additional species data, including notably predicted inversion agents TiO VO, their atomic constituents Ti\,\textsc{i}...
Abstract We study the emergent spectral fluxes of transiting hot Jupiters, using secondary eclipses from Spitzer. To achieve a large and uniform sample, we have reanalyzed all for Jupiters observed by Spitzer at 3.6 and/or 4.5 μ m. Our sample comprises 457 122 planets, including 13 planets not previously published. use these eclipse depths to calculate exoplanetary atmospheres, thereby infer temperatures properties Jupiters. find that an abrupt rise in brightness temperature, similar phase...
Know thy star, know planetary atmosphere. Every exoplanet with atmospheric measurements orbits around a and the stellar environment directly affects Here we present emission spectrum of ultra-hot Jupiter KELT-20b which provides an observational link between host star properties planet thermal structure. It is currently only in $T_{eq}\sim$2200K range that early A-type star. By comparing it other similar Jupiters FGK stars, can better understand how different types influence atmospheres. The...
We present a uniform analysis of transit observations from the Hubble Space Telescope and Spitzer two warm gas giants orbiting K-type stars - WASP-29b WASP-80b. The transmission spectra, which span 0.4-5.0 $\mu$m, are interpreted using suite chemical equilibrium PLATON atmospheric retrievals. Both planets show evidence significant aerosol opacity along day-night terminator. spectrum is flat throughout visible near-infrared, suggesting presence condensate clouds extending to low pressures....
Carbon dioxide (CO2) is a key chemical species that found in wide range of planetary atmospheres. In the context exoplanets, CO2 an indicator metal enrichment (i.e., elements heavier than helium, also called "metallicity"), and thus formation processes primary atmospheres hot gas giants. It one most promising to detect secondary terrestrial exoplanets. Previous photometric measurements transiting planets with Spitzer Space Telescope have given hints presence but not yielded definitive...
Abstract Ultra-hot Jupiters with equilibrium temperatures greater than 2000 K are uniquely interesting targets as they provide us crucial insights into how atmospheres behave under extreme conditions. This class of giant planets receives intense radiation from their host star and usually has strongly irradiated highly inflated atmospheres. At such a high temperature, cloud formation is expected to be suppressed thermal dissociation water vapor could occur. We observed the ultra-hot Jupiter...
As the closest transiting hot Jupiter to Earth, HD 189733b has been benchmark planet for atmospheric characterization. It also anchor point much of our theoretical understanding exoplanet atmospheres from composition, chemistry, aerosols dynamics, escape, and modeling techniques. Prior studies have detected carbon oxygen-bearing molecules H2O CO in atmosphere. The presence CO2 CH4 claimed but later disputed. inferred metallicity based on these measurements, a key parameter tracing formation...
Abstract The Mid-Infrared Instrument Medium Resolution Spectrometer (the MRS) on JWST has potentially important advantages for transit and eclipse spectroscopy of exoplanets, including lack saturation bright host stars, wavelength span to longward 20 µ m, JWST’s highest spectral resolving power. We here test the performance MRS time series by observing secondary stellar eclipsing binary R Canis Majoris. Our observations push into at shortest wavelength, more than any currently known...
Abstract Kepler-51 is a ≲1 Gyr old Sun-like star hosting three transiting planets with radii ≈6–9 R ⊕ and orbital periods ≈45–130 days. Transit timing variations (TTVs) measured past Kepler Hubble Space Telescope (HST) observations have been successfully modeled by considering gravitational interactions between the planets, yielding low masses mean densities (≲0.1 g cm −3 ) for all planets. However, transit time of outermost planet Kepler-51d recently James Webb 10 yr after significantly...
Planets are like children with each one being unique and special. A better understanding of their collective properties requires a deeper planet. Here we add the transit eclipse spectra hot Jupiter WASP-74b into ever growing dataset exoplanet atmosphere spectral library. With six transits three eclipses using Hubble Space Telescope (HST) Spitzer (\textit{Spitzer}), present most complete precise atmospheric WASP-74b. We found no evidence for TiO/VO nor super-Rayleigh scattering reported in...