Search Publications
SOAR TESS Survey. II. The Impact of Stellar Companions on Planetary Populations
Ziegler, Carl; Tokovinin, Andrei; Mann, Andrew W. +3 more
We present the results of the second year of exoplanet candidate host speckle observations from the SOAR TESS survey. We find 89 of the 589 newly observed TESS planet candidate hosts have companions within 3″, resulting in light-curve dilution, that, if not accounted for, leads to underestimated planetary radii. We combined these observations with…
Evolution of the Exoplanet Size Distribution: Forming Large Super-Earths Over Billions of Years
Angus, Ruth; Foreman-Mackey, Daniel; Bedell, Megan +8 more
The radius valley, a bifurcation in the size distribution of small, close-in exoplanets, is hypothesized to be a signature of planetary atmospheric loss. Such an evolutionary phenomenon should depend on the age of the star-planet system. In this work, we study the temporal evolution of the radius valley using two independent determinations of host…
Systematic KMTNet Planetary Anomaly Search. I. OGLE-2019-BLG-1053Lb, a Buried Terrestrial Planet
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +71 more
In order to exhume the buried signatures of "missing planetary caustics" in Korea Microlensing Telescope Network (KMTNet) data, we conducted a systematic anomaly search of the residuals from point-source point-lens fits, based on a modified version of the KMTNet EventFinder algorithm. This search revealed the lowest-mass-ratio planetary caustic to…
Spitzer Phase-curve Observations and Circulation Models of the Inflated Ultrahot Jupiter WASP-76b
Deming, Drake; Fortney, Jonathan J.; Stevenson, Kevin B. +15 more
The large radii of many hot Jupiters can only be matched by models that have hot interior adiabats, and recent theoretical work has shown that the interior evolution of hot Jupiters has a significant impact on their atmospheric structure. Due to its inflated radius, low gravity, and ultrahot equilibrium temperature, WASP-76b is an ideal case study…
TIC 172900988: A Transiting Circumbinary Planet Detected in One Sector of TESS Data
Kostov, Veselin B.; Powell, Brian P.; Torres, Guillermo +85 more
We report the first discovery of a transiting circumbinary planet detected from a single sector of Transiting Exoplanet Survey Satellite (TESS) data. During Sector 21, the planet TIC 172900988b transited the primary star and then five days later it transited the secondary star. The binary is itself eclipsing, with a period P ≈ 19.7 days and an ecc…
Speckle Observations of TESS Exoplanet Host Stars: Understanding the Binary Exoplanet Host Star Orbital Period Distribution
Howell, Steve B.; Winn, Joshua N.; Ciardi, David R. +5 more
We present high-resolution speckle interferometric imaging observations of TESS exoplanet host stars using the NN-EXPLORE Exoplanet and Stellar Speckle Imager instrument at the 3.5 m WIYN telescope. Eight TESS objects of interest that were originally discovered by Kepler were previously observed using the Differential Speckle Survey Instrument. Sp…
A More Precise Mass for GJ 1214 b and the Frequency of Multiplanet Systems Around Mid-M Dwarfs
Deming, Drake; Charbonneau, David; Cloutier, Ryan +2 more
We present an intensive effort to refine the mass and orbit of the enveloped terrestrial planet GJ 1214 b using 165 radial velocity (RV) measurements taken with the HARPS spectrograph over a period of 10 years. We conduct a joint analysis of the RVs with archival Spitzer/IRAC transits and measure a planetary mass and radius of 8.17 ± 0.43 M⊕<…
OGLE-2018-BLG-0567Lb and OGLE-2018-BLG-0962Lb: Two Microlensing Planets through the Planetary-caustic Channel
Han, Cheongho; Udalski, Andrzej; Lee, Chung-Uk +32 more
We present the analyses of two microlensing events, OGLE-2018-BLG-0567 and OGLE-2018-BLG-0962. In both events, the short-lasting anomalies were densely and continuously covered by two high-cadence surveys. The light-curve modeling indicates that the anomalies are generated by source crossings over the planetary caustics induced by planetary compan…
The TESS-Keck Survey. II. An Ultra-short-period Rocky Planet and Its Siblings Transiting the Galactic Thick-disk Star TOI-561
Batalha, Natalie M.; Kane, Stephen R.; Stassun, Keivan G. +61 more
We report the discovery of TOI-561, a multiplanet system in the galactic thick disk that contains a rocky, ultra-short-period planet. This bright (V = 10.2) star hosts three small transiting planets identified in photometry from the NASA TESS mission: TOI-561 b (TOI-561.02, P = 0.44 days, Rp = 1.45 ± 0.11 R⊕), c (TOI-561.01, …
Cometary Activity Begins at Kuiper Belt Distances: Evidence from C/2017 K2
Mutchler, Max; Jewitt, David; Agarwal, Jessica +3 more
We study the development of activity in the incoming long-period comet C/2017 K2 over the heliocentric distance range 9 ≲ rH ≲ 16 au. The comet continues to be characterized by a coma of submillimeter-sized and larger particles ejected at low velocity. In a fixed co-moving volume around the nucleus we find that the scattering cross sect…