Search Publications
The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence for a Cloud-free Primordial Atmosphere and Constraints on Starspot Contamination
Désert, Jean-Michel; Rackham, Benjamin V.; Morley, Caroline V. +10 more
Orbiting an M dwarf 12 pc away, the transiting exoplanet GJ 1132b is a prime target for transmission spectroscopy. With a mass of 1.7 M ⊕ and radius of 1.1 R ⊕, GJ 1132b's bulk density indicates that this planet is rocky. Yet with an equilibrium temperature of 580 K, GJ 1132b may still retain some semblance of an atmosphere. …
Escaping Helium from TOI 560.01, a Young Mini-Neptune
Knutson, Heather A.; Dai, Fei; Zhang, Michael +2 more
We report helium absorption from the escaping atmosphere of TOI 560.01 (HD 73583b), an R = 2.8R ⊕, P = 6.4 day mini-Neptune orbiting a young (~600 Myr) K dwarf. Using Keck/NIRSPEC, we detect a signal with an average depth of 0.68% ± 0.08% in the line core. The absorption signal repeats during a partial transit obtained a month later, bu…
Classifying Be Star Variability With TESS. I. The Southern Ecliptic
Labadie-Bartz, Jonathan; Carciofi, Alex C.; Henrique de Amorim, Tajan +4 more
TESS photometry is analyzed for 430 classical Be stars observed in the first year of the mission. The often complex and diverse variability of each object in this sample is classified to obtain an understanding of the behavior of this class as a population. Ninety-seven percent of the systems are variable above the noise level, with timescales spa…
A 20 Second Cadence View of Solar-type Stars and Their Planets with TESS: Asteroseismology of Solar Analogs and a Recharacterization of π Men c
Barclay, Thomas; Chaplin, William J.; Hermes, J. J. +50 more
We present an analysis of the first 20 second cadence light curves obtained by the TESS space telescope during its extended mission. We find improved precision of 20 second data compared to 2 minute data for bright stars when binned to the same cadence (≈10%-25% better for T ≲ 8 mag, reaching equal precision at T ≈ 13 mag), consistent with pre-fli…
Scanning Disk Rings and Winds in CO at 0.01-10 au: A High-resolution M-band Spectroscopy Survey with IRTF-iSHELL
Banzatti, Andrea; Bosman, Arthur D.; Pontoppidan, Klaus M. +11 more
We present an overview and first results from a M-band spectroscopic survey of planet-forming disks performed with iSHELL on the Infrared Telescope Facility, using two slits that provide resolving power R ≈ 60,000-92,000 (5-3.3 km s-1). iSHELL provides a nearly complete coverage at 4.52-5.24 µm in one shot, covering >50 lines f…
The Stellar Halo of the Galaxy is Tilted and Doubly Broken
Conroy, Charlie; Ting, Yuan-Sen; Johnson, Benjamin D. +7 more
Modern Galactic surveys have revealed an ancient merger that dominates the stellar halo of our galaxy (Gaia-Sausage-Enceladus, GSE). Using chemical abundances and kinematics from the H3 Survey, we identify 5559 halo stars from this merger in the radial range r Gal = 6-60kpc. We forward model the full selection function of H3 to infer th…
A Second Planet Transiting LTT 1445A and a Determination of the Masses of Both Worlds
Butler, R. Paul; Kristiansen, Martti H.; Omohundro, Mark +79 more
LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 pc. The primary star LTT 1445A (0.257 M ⊙) is known to host the transiting planet LTT 1445Ab with an orbital period of 5.36 days, making it the second-closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using …
Keck/NIRSPEC Studies of He I in the Atmospheres of Two Inflated Hot Gas Giants Orbiting K Dwarfs: WASP-52b and WASP-177b
Kirk, James; López-Morales, Mercedes; Alam, Munazza K. +5 more
We present the detection of neutral helium at 10833 Å in the atmosphere of WASP-52b and tentative evidence of helium in the atmosphere of the grazing WASP-177b, using high-resolution observations acquired with the NIRSPEC instrument on the Keck II telescope. We detect excess absorption by helium in WASP-52b's atmosphere of 3.44% ± 0.31% (11σ), or …
A Census of the Stellar Populations in the Sco-Cen Complex
Luhman, K. L.
I have used high-precision photometry and astrometry from the early installment of the third data release of Gaia (EDR3) to perform a survey for members of the stellar populations within the Sco-Cen complex, which consist of Upper Sco, UCL/LCC, the V1062 Sco group, Ophiuchus, and Lupus. Among Gaia sources with σ π < 1 mas, I have i…
The TESS-Keck Survey: Science Goals and Target Selection
Batalha, Natalie M.; Bieryla, Allyson; Latham, David W. +62 more
The Kepler and TESS missions have demonstrated that planets are ubiquitous. However, the success of these missions heavily depends on ground-based radial velocity (RV) surveys, which combined with transit photometry can yield bulk densities and orbital properties. While most Kepler host stars are too faint for detailed follow-up observations, TESS…