1.8k citations · 3.3k across the 26 of their papers we have counts for
26 papers
Sulphur dioxide in the mid-infrared transmission spectrum of WASP-39b
Diana Powell, Adina D. Feinstein, Elspeth K. H. Lee +70
The recent inference of sulphur dioxide (SO) in the atmosphere of the hot (1100 K), Saturn-mass exoplanet WASP-39b from near-infrared JWST observations suggests that phot…
Identifying and Fitting Eclipse Maps of Exoplanets with Cross-Validation
Mark Hammond, Neil T. Lewis, Sasha Boone +10
Eclipse mapping uses the shape of the eclipse of an exoplanet to measure its two-dimensional structure. Light curves are mostly composed of longitudinal information, with the latit…
Outflowing helium from a mature mini-Neptune
Michael Zhang, Fei Dai, Jacob L. Bean +2
We announce the detection of escaping helium from TOI 2134b, a mini-Neptune a few Gyr old. The average in-transit absorption spectrum shows a peak of 0.37 +- 0.05% and an equivalen…
Transmission spectroscopy of the lowest-density gas giant: metals and a potential extended outflow in HAT-P-67b
Aaron Bello-Arufe, Heather A. Knutson, João M. Mendonça +6
Extremely low-density exoplanets are tantalizing targets for atmospheric characterization because of their promisingly large signals in transmission spectroscopy. We present the fi…
A reflective, metal-rich atmosphere for GJ 1214b from its JWST phase curve
Eliza M. -R. Kempton, Michael Zhang, Jacob L. Bean +30
There are no planets intermediate in size between Earth and Neptune in our Solar System, yet these objects are found around a substantial fraction of other stars. Population statis…
The Hazy and Metal-Rich Atmosphere of GJ 1214 b Constrained by Near and Mid-Infrared Transmission Spectroscopy
Peter Gao, Anjali A. A. Piette, Maria E. Steinrueck +12
The near-infrared transmission spectrum of the warm sub-Neptune exoplanet GJ 1214 b has been observed to be flat and featureless, implying a high metallicity atmosphere with abunda…
Confirmation of sub-solar metallicity for WASP-77Ab from JWST thermal emission spectroscopy
Prune C. August, Jacob L. Bean, Michael Zhang +4
We present the dayside thermal emission spectrum of WASP-77Ab from 2.8 -- 5.2 m as observed with the NIRSpec instrument on the James Webb Space Telescope (JWST). WASP-77Ab was p…
High atmospheric metal enrichment for a Saturn-mass planet
Jacob L. Bean, Qiao Xue, Prune C. August +9
Atmospheric metal enrichment (i.e., elements heavier than helium, also called "metallicity") is a key diagnostic of the formation of giant planets. The giant planets of the solar s…
Non-detection of He I in the atmosphere of GJ1214b with Keck/NIRSPEC, at a time of minimal telluric contamination
Jessica J. Spake, Antonija Oklopčić, Lynne. A. Hillenbrand +7
Observations of helium in exoplanet atmospheres may reveal the presence of large gaseous envelopes, and indicate ongoing atmospheric escape. Orell-Miquel et al. (2022) used CARMENE…
Detection of Atmospheric Escape from Four Young Mini Neptunes
Michael Zhang, Heather A. Knutson, Fei Dai +5
We use Keck/NIRSPEC to survey a sample of of young (1 Gyr), short period mini Neptunes orbiting nearby K dwargs to measure their mass loss via the metastable helium line. We det…
More Evidence for Variable Helium Absorption from HD 189733b
Michael Zhang, P. Wilson Cauley, Heather A. Knutson +5
We present a new Keck/NIRSPEC observation of metastable helium absorption from the upper atmosphere of HD 189733b, a hot Jupiter orbiting a nearby moderately active star. We measur…
Escaping Helium from TOI 560.01, a Young Mini Neptune
Michael Zhang, Heather A. Knutson, Lile Wang +2
We report helium absorption from the escaping atmosphere of TOI 560.01 (HD 73583b), a , d mini Neptune orbiting a young (600 Myr) K dwarf. Using Keck/…
Detection of Ongoing Mass Loss from HD 63433c, a Young Mini Neptune
Michael Zhang, Heather A. Knutson, Lile Wang +9
We detect Lyman absorption from the escaping atmosphere of HD 63433c, a , d mini Neptune orbiting a young (440 Myr) solar analogue in the Ursa Major M…
No escaping helium from 55 Cnc e
Michael Zhang, Heather A. Knutson, Lile Wang +3
We search for escaping helium from the hot super Earth 55 Cnc e by taking high-resolution spectra of the 1083 nm line during two transits using Keck/NIRSPEC. We detect no helium ab…
PLATON II: New Capabilities And A Comprehensive Retrieval on HD 189733b Transit and Eclipse Data
Michael Zhang, Yayaati Chachan, Eliza M. -R. Kempton +3
Recently, we introduced PLanetary Atmospheric Tool for Observer Noobs (PLATON), a Python package that calculates model transmission spectra for exoplanets and retrieves atmospheric…
The Orbit of WASP-12b is Decaying
Samuel W. Yee, Joshua N. Winn, Heather A. Knutson +6
WASP-12b is a transiting hot Jupiter on a 1.09-day orbit around a late-F star. Since the planet's discovery in 2008, the time interval between transits has been decreasing by $29\p…
A Hubble PanCET Study of HAT-P-11b: A Cloudy Neptune with a Low Atmospheric Metallicity
Yayaati Chachan, Heather A. Knutson, Peter Gao +14
We present the first comprehensive look at the m transmission spectrum of the warm ( K) Neptune HAT-P-11b derived from thirteen individual transits observed u…
Mass Loss from the Exoplanet WASP-12b Inferred from Phase Curves
Taylor J. Bell, Michael Zhang, Patricio E. Cubillos +12
The exoplanet WASP-12b is the prototype for the emerging class of ultra-hot, Jupiter-mass exoplanets. Past models have predicted---and near ultra-violet observations have shown---t…
Modules for Experiments in Stellar Astrophysics (MESA): Pulsating Variable Stars, Rotation, Convective Boundaries, and Energy Conservation
Bill Paxton, R. Smolec, Josiah Schwab +14
We update the capabilities of the open-knowledge software instrument Modules for Experiments in Stellar Astrophysics (MESA). RSP is a new functionality in MESAstar that models the…
The long-term evolution and appearance of Type Iax postgenitor stars
Michael Zhang, Jim Fuller, Josiah Schwab +1
Type Iax supernovae may arise from failed explosions of white dwarfs that leave behind a bound remnant (i.e., a "postgenitor" star) that could be identified in wide field surveys.…
Forward modelling and retrievals with PLATON, a fast open source tool
Michael Zhang, Yayaati Chachan, Eliza M. -R. Kempton +1
We introduce PLanetary Atmospheric Transmission for Observer Noobs (PLATON), a Python package that calculates transmission spectra for exoplanets and retrieves atmospheric characte…
Detection of a Westward Hotspot Offset in the Atmosphere of a Hot Gas Giant CoRoT-2b
Lisa Dang, Nicolas B. Cowan, Joel C. Schwartz +9
Short-period planets exhibit day-night temperature contrasts of hundreds to thousands of degrees K. They also exhibit eastward hotspot offsets whereby the hottest region on the pla…
Phase curves of WASP-33b and HD 149026b and a New Correlation Between Phase Curve Offset and Irradiation Temperature
Michael Zhang, Heather A. Knutson, Tiffany Kataria +9
We present new 3.6 and 4.5 Spitzer phase curves for the highly irradiated hot Jupiter WASP-33b and the unusually dense Saturn-mass planet HD 149026b. As part of this analysis,…
Precision multi-band photometry with a DSLR camera
M. Zhang, G. Á. Bakos, K. Penev +4
Ground-based exoplanet surveys such as SuperWASP, HATNet and KELT have discovered close to two hundred transiting extrasolar planets in the past several years. The strategy of thes…