A Search for Exozodiacal Clouds with Kepler

Planets embedded within dust disks may drive the formation of large scale clumpy dust structures by trapping dust into resonant orbits. Detection and subsequent modeling of the dust structures would help constrain the mass and orbit of the planet and the disk architecture, give clues to the history of the planetary system, and provide a statistical estimate of disk asymmetry for future exoEarth-imaging missions. Here we present the first search for these resonant structures in the inner regions of planetary systems by analyzing the light curves of hot Jupiter planetary candidates identified by the Kepler mission. We detect only one candidate disk structure associated with KOI 838.01 at the 3-sigma confidence level, but subsequent radial velocity measurements reveal that KOI 838.01 is a grazing eclipsing binary and the candidate disk structure is a false positive. Using our null result, we place an upper limit on the frequency of dense exozodi structures created by hot Jupiters. We find that at the 90% confidence level, less than 21% of Kepler hot Jupiters create resonant dust clumps that lead and trail the planet by ~90 degrees with optical depths >~5*10^-6, which corresponds to the resonant structure expected for a lone hot Jupiter perturbing a dynamically cold dust disk 50 times as dense as the zodiacal cloud.Comment: 22 pages, 6 figures, Accepted for publication in Ap

Equivalence problem for the orthogonal webs on the sphere

We solve the equivalence problem for the orthogonally separable webs on the three-sphere under the action of the isometry group. This continues a classical project initiated by Olevsky in which he solved the corresponding canonical forms problem. The solution to the equivalence problem together with the results by Olevsky forms a complete solution to the problem of orthogonal separation of variables to the Hamilton-Jacobi equation defined on the three-sphere via orthogonal separation of variables. It is based on invariant properties of the characteristic Killing two-tensors in addition to properties of the corresponding algebraic curvature tensor and the associated Ricci tensor. The result is illustrated by a non-trivial application to a natural Hamiltonian defined on the three-sphere.Comment: 32 page

A 12-year activity cycle for the nearby planet host star HD 219134

The nearby (6.5 pc) star HD 219134 was recently shown by Motalebi et al. and Vogt et al. to host several planets, the innermost of which is transiting. We present 27 years of radial velocity (RV) observations of this star from the McDonald Observatory Planet Search program, and 19 years of stellar activity data. We detect a long-period activity cycle measured in the Ca II SHK index, with a period of 4230±100 days (11.7 years), very similar to the 11 year solar activity cycle. Although the period of the Saturn-mass planet HD 219134 h is close to half that of the activity cycle, we argue that it is not an artifact due to stellar activity. We also find a significant periodicity in the SHK data due to stellar rotation with a period of 22.8 days. This is identical to the period of planet f identified by Vogt et al., suggesting that this RV signal might be caused by rotational modulation of stellar activity rather than a planet. Analysis of our RVs allows us to detect the long-period planet HD 219134 h and the transiting super-Earth HD 219134 b. Finally, we use our long time baseline to constrain the presence of longer period planets in the system, excluding to 1s objects with M sin i > 0.36MJ at 12 years (corresponding to the orbital period of Jupiter) and M sin i > 0.72MJ at a period of 16.4 years (assuming a circular orbit for an outer companion)

Attributing scientific and technical progress: the case of holography

Holography, the three-dimensional imaging technology, was portrayed widely as a paradigm of progress during its decade of explosive expansion 1964–73, and during its subsequent consolidation for commercial and artistic uses up to the mid 1980s. An unusually seductive and prolific subject, holography successively spawned scientific insights, putative applications and new constituencies of practitioners and consumers. Waves of forecasts, associated with different sponsors and user communities, cast holography as a field on the verge of success—but with the dimensions of success repeatedly refashioned. This retargeting of the subject represented a degree of cynical marketeering, but was underpinned by implicit confidence in philosophical positivism and faith in technological progressivism. Each of its communities defined success in terms of expansion, and anticipated continual progressive increase. This paper discusses the contrasting definitions of progress in holography, and how they were fashioned in changing contexts. Focusing equally on reputed ‘failures’ of some aspects of the subject, it explores the varied attributes by which success and failure were linked with progress by different technical communities. This important case illuminates the peculiar post-World War II environment that melded the military, commercial and popular engagement with scientific and technological subjects, and the competing criteria by which they assessed the products of science

Two New Long-Period Giant Planets from the McDonald Observatory Planet Search and Two Stars with Long-Period Radial Velocity Signals Related to Stellar Activity Cycles

We report the detection of two new long-period giant planets orbiting the stars HD 95872 and HD 162004 (ψ^1 Dra B) by the McDonald Observatory planet search. The planet HD 95872b has a minimum mass of 4.6 M_(Jup) and an orbital semimajor axis of 5.2 AU. The giant planet ψ^1 Dra Bb has a minimum mass of 1.5 M_(Jup) and an orbital semimajor axis of 4.4 AU. Both of these planets qualify as Jupiter analogs. These results are based on over one and a half decades of precise radial velocity (RV) measurements collected by our program using the McDonald Observatory Tull Coude spectrograph at the 2.7 m Harlan J. Smith Telescope. In the case of ψ^1 Dra B we also detect a long-term nonlinear trend in our data that indicates the presence of an additional giant planet, similar to the Jupiter–Saturn pair. The primary of the binary star system, ψ^1 Dra A, exhibits a very large amplitude RV variation due to another stellar companion. We detect this additional member using speckle imaging. We also report two cases—HD 10086 and HD 102870 (β Virginis)—of significant RV variation consistent with the presence of a planet, but that are probably caused by stellar activity, rather than reflexive Keplerian motion. These two cases stress the importance of monitoring the magnetic activity level of a target star, as long-term activity cycles can mimic the presence of a Jupiter-analog planet

Radial Velocity Discovery of an Eccentric Jovian World Orbiting at 18 au

Based on two decades of radial velocity (RV) observations using Keck/High Resolution Echelle Spectrometer (HIRES) and McDonald/Tull, and more recent observations using the Automated Planet Finder, we found that the nearby star HR 5183 (HD 120066) hosts a 3 minimum mass planet with an orbital period of yr. The orbit is highly eccentric (e ≃ 0.84), shuttling the planet from within the orbit of Jupiter to beyond the orbit of Neptune. Our careful survey design enabled high cadence observations before, during, and after the planet\u27s periastron passage, yielding precise orbital parameter constraints. We searched for stellar or planetary companions that could have excited the planet\u27s eccentricity, but found no candidates, potentially implying that the perturber was ejected from the system. We did identify a bound stellar companion more than 15,000 au from the primary, but reasoned that it is currently too widely separated to have an appreciable effect on HR 5183 b. Because HR 5183 b\u27s wide orbit takes it more than 30 au (1\u27\u27) from its star, we also explored the potential of complimentary studies with direct imaging or stellar astrometry. We found that a Gaia detection is very likely, and that imaging at 10 μm is a promising avenue. This discovery highlights the value of long-baseline RV surveys for discovering and characterizing long-period, eccentric Jovian planets. This population may offer important insights into the dynamical evolution of planetary systems containing multiple massive planets

The unusual M-dwarf Warm Jupiter TOI-1899~b: Refinement of orbital and planetary parameters

TOI-1899~b is a rare exoplanet, a temperate Warm Jupiter orbiting an M-dwarf, first discovered by \citet{Canas2020_toi1899} from a TESS single-transit event. Using new radial velocities (RVs) from the precision RV spectrographs HPF and NEID, along with additional TESS photometry and ground-based transit follow-up, we are able to derive a much more precise orbital period of $P = 29.090312_{-0.000035}^{+0.000036}$~d, along with a radius of $R_p = 0.99\pm0.03$~\unit{R_{J}}. We have also improved the constraints on planet mass, $M_p = 0.67\pm{0.04}$~\unit{M_{J}}, and eccentricity, which is consistent with a circular orbit at 2$\sigma$ ($e = 0.044_{-0.027}^{+0.029}$). TOI-1899~b occupies a unique region of parameter space as the coolest known ($T_{eq} \approx$ 380~K) Jovian-sized transiting planet around an M-dwarf; we show that it has great potential to provide clues regarding the formation and migration mechanisms of these rare gas giants through transmission spectroscopy with JWST as well as studies of tidal evolution.Comment: 19 pages, 7 figures, 3 tables, submitted to AJ (comments welcome

Transiting circumbinary planets Kepler-34 b and Kepler-35 b

Most Sun-like stars in the Galaxy reside in gravitationally bound pairs of stars (binaries). Although long anticipated the existence of a ‘circumbinary planet’ orbiting such a pair of normal stars was not definitively established until the discovery of the planet transiting (that is, passing in front of) Kepler-16. Questions remained, however, about the prevalence of circumbinary planets and their range of orbital and physical properties. Here we report two additional transiting circumbinary planets: Kepler-34 (AB)b and Kepler-35 (AB)b, referred to here as Kepler-34 b and Kepler-35 b, respectively. Each is a low-density gas-giant planet on an orbit closely aligned with that of its parent stars. Kepler-34 b orbits two Sun-like stars every 289 days, whereas Kepler-35 b orbits a pair of smaller stars (89% and 81% of the Sun’s mass) every 131 days. The planets experience large multi-periodic variations in incident stellar radiation arising from the orbital motion of the stars. The observed rate of circumbinary planets in our sample implies that more than ~1% of close binary stars have giant planets in nearly coplanar orbits, yielding a Galactic population of at least several million