Search Publications
A Free-floating or Wide-orbit Planet in the Microlensing Event OGLE-2019-BLG-0551
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +32 more
High-cadence observations of the Galactic bulge by the microlensing surveys led to the discovery of a handful of extremely short-timescale microlensing events that can be attributed to free-floating or wide-orbit planets. Here, we report the discovery of another strong free-floating planet candidate, which was found from the analysis of the gravit…
Size and Shape Constraints of (486958) Arrokoth from Stellar Occultations
Dunham, David W.; Tanga, Paolo; Singer, Kelsi N. +130 more
We present the results from four stellar occultations by (486958) Arrokoth, the flyby target of the New Horizons extended mission. Three of the four efforts led to positive detections of the body, and all constrained the presence of rings and other debris, finding none. Twenty-five mobile stations were deployed for 2017 June 3 and augmented by fix…
The Breakthrough Listen Search for Intelligent Life: A 3.95-8.00 GHz Search for Radio Technosignatures in the Restricted Earth Transit Zone
Kalas, Paul; Gajjar, Vishal; Isaacson, Howard +5 more
We report on a search for artificial narrowband signals of 20 stars within the restricted Earth Transit Zone (rETZ) as a part of the ten-year Breakthrough Listen (BL) search for extraterrestrial intelligence (ETI). The rETZ is the region of the sky from which an observer would see Earth transit the Sun with an impact parameter of less than 0.5. Th…
The First Light Curve Modeling and Orbital Period Change Investigation of Nine Contact Binaries around the Short-period Cutoff
Li, Kai; Xia, Qi-Qi; Gao, Xing +5 more
In this paper, we present the first light curve synthesis and orbital period change analysis of nine contact binaries around the short-period limit. It is found that all these systems are W-subtype contact binaries. One of them is a medium contact system while the others are shallow contact ones. Four of them manifest obvious O'Connell effect expl…
Orbital Stability of Circumstellar Planets in Binary Systems
Li, Gongjie; Kostov, Veselin; Haghighipour, Nader +1 more
Planets that orbit only one of the stars in stellar binary systems (i.e., circumstellar) are dynamically constrained to a limited range of orbital parameters, and understanding conditions on their stability is thus of great importance in exoplanet searches. We perform ∼700 million N-body simulations to identify how stability regions depend on prop…
Kepler-1661 b: A Neptune-sized Kepler Transiting Circumbinary Planet around a Grazing Eclipsing Binary
Torres, Guillermo; Cochran, William D.; Endl, Michael +7 more
We report the discovery of a Neptune-sized ( ${R}_{p}=3.87\pm 0.06{R}_{\oplus }$ ) transiting circumbinary planet, Kepler-1661 b, found in the Kepler photometry. The planet has a period of ∼175 days and its orbit precesses with a period of only 35 yr. The precession causes the alignment of the orbital planes to vary, and the planet is in a transit…
Mutual Orbital Inclinations between Cold Jupiters and Inner Super-Earths
Winn, Joshua N.; Kawahara, Hajime; Masuda, Kento
Previous analyses of Doppler and Kepler data have found that Sun-like stars hosting “cold Jupiters” (giant planets with a ≳ 1 au) almost always host “inner super-Earths” (1-4 R ⊕, a ≲ 1 au). Here we attempt to determine the degree of alignment between the orbital planes of the cold Jupiters and the inner super-Earths. The key observatio…
The Gemini Planet Imager Exoplanet Survey: Dynamical Mass of the Exoplanet β Pictoris b from Combined Direct Imaging and Astrometry
Duchêne, Gaspard; Esposito, Thomas M.; Oppenheimer, Rebecca +51 more
We present new observations of the planet β Pictoris b from 2018 with the Gemini Planet Imager (GPI), the first GPI observations following conjunction. Based on these new measurements, we perform a joint orbit fit to the available relative astrometry from ground-based imaging, the Hipparcos Intermediate Astrometric Data (IAD), and the Gaia DR2 pos…
TOI-1235 b: A Keystone Super-Earth for Testing Radius Valley Emergence Models around Early M Dwarfs
López-Morales, Mercedes; Latham, David W.; Esquerdo, Gilbert A. +85 more
Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/nonrocky…
A Closer Look at Exoplanet Occurrence Rates: Considering the Multiplicity of Stars without Detected Planets
Mayo, Andrew W.; Hirsch, Lea A.; Ciardi, David R. +5 more
One core goal of the Kepler mission was to determine the frequency of Earth-like planets that orbit Sun-like stars. Accurately estimating this planet occurrence rate requires both a well-vetted list of planets and a clear understanding of the stars searched for planets. Previous ground-based follow-up observations have, through a variety of method…