Eccentricity and Spin-Orbit Misalignment in Short-Period Stellar Binaries as a Signpost of Hidden Tertiary Companions

Eclipsing binaries are observed to have a range of eccentricities and spin-orbit misalignments (stellar obliquities). Whether such properties are primordial, or arise from post-formation dynamical interactions remains uncertain. This paper considers the scenario in which the binary is the inner component of a hierarchical triple stellar system, and derives the requirements that the tertiary companion must satisfy in order to raise the eccentricity and obliquity of the inner binary. Through numerical integrations of the secular octupole-order equations of motion of stellar triples, coupled with the spin precession of the oblate primary star due to the torque from the secondary, we obtain a simple, robust condition for producing spin-orbit misalignment in the inner binary: In order to excite appreciable obliquity, the precession rate of the stellar spin axis must be smaller than the orbital precession rate due to the tertiary companion. This yields quantitative requirements on the mass and orbit of the tertiary. We also present new analytic expressions for the maximum eccentricity and range of inclinations allowing eccentricity excitation (Lidov-Kozai window), for stellar triples with arbitrary masses and including the non-Keplerian potentials introduced by general relativity, stellar tides and rotational bulges. The results of this paper can be used to place constraints on unobserved tertiary companions in binaries that exhibit high eccentricity and/or spin-orbit misalignment, and will be helpful in guiding efforts to detect external companions around stellar binaries. As an application, we consider the eclipsing binary DI Herculis, and identify the requirements that a tertiary companion must satisfy to produce the observed spin-orbit misalignment.Comment: 19 pages, 15 figures, accepted for publication in MNRA

Chaotic Dynamics of Stellar Spin in Binaries and the Production of Misaligned Hot Jupiters

Many exoplanetary systems containing hot Jupiters are observed to have highly misaligned orbital axes relative to the stellar spin axes. Kozai-Lidov oscillations of orbital eccentricity/inclination induced by a binary companion, in conjunction with tidal dissipation, is a major channel for the production of hot Jupiters. We demonstrate that gravitational interaction between the planet and its oblate host star can lead to chaotic evolution of the stellar spin axis during Kozai cycles. As parameters such as the planet mass and stellar rotation period vary, periodic islands can appear in an ocean of chaos, in a manner reminiscent of other dynamical systems. In the presence of tidal dissipation, the complex spin evolution can leave an imprint on the final spin-orbit misalignment angles.Comment: 26 pages, 13 figures. Includes supplementary materials. To be published in the September 12, 2014 edition of Science Magazine. For additional information, please visit http://astro.cornell.edu/~dong/sciencepaper.htm

The Seiberg-Witten prepotential and the Euler class of the reduced moduli space of instantons

The n-instanton contribution to the Seiberg-Witten prepotential of N=2 supersymmetric d=4 Yang Mills theory is represented as the integral of the exponential of an equivariantly exact form. Integrating out an overall scale and a U(1) angle the integral is rewritten as (4n-3) fold product of a closed two form. This two form is, formally, a representative of the Euler class of the Instanton moduli space viewed as a principal U(1) bundle, because its pullback under bundel projection is the exterior derivative of an angular one-form.Comment: LaTex, 15 page

Maneuver Estimation Model for Relative Orbit Determination

While the use of relative orbit determination has reduced the difficulties inherent in tracking geosynchronous satellites that are in close proximity, the problem is often compounded by stationkeeping operations or unexpected maneuvers. If a maneuver occurs, observations will no longer fit predicted data, increasing the risk of misidentification and cross-tagging. The goal of this research was to develop a model that will estimate the magnitude, direction, and time of a suspected maneuver performed by a collocated satellite in geosynchronous orbit. Relative motion was modelled using Hill\u27s equations, and least squares estimation was employed to create both a linear non-maneuver model and non-linear maneuver model. Two sets of data (DirecTV 4S and AMC-4) for an actual satellite collocation were obtained from the Air Force Maui Optical and Supercomputing (AMOS) site, consisting of differential right ascension and declination. Studies conducted with these observations, along with simulation studies, indicate that it is possible to perform maneuver estimation. It was found, however, that the amount of data required for successful convergence is much greater than that typically obtained for tracking purposes

TB43: Field Recognition of the Larvae of Native Coccinellidae Common to the Potato Fields of Aroostook County

The adult beetles of the family Coccinellidae are the well-known ladybird beetles or ladybugs. The larvae and adults of the subfamily Coccinellinae are considered beneficial because they feed on pest species, mainly aphids and scale insects. This study was undertaken to provide a means of recognizing the larvae of native coccinellids found in or around the potato fields of Aroostook County. For our purposes, it is desirable to be able to identify the insect quickly and without killing it. Thus, the larval color pattern was chosen as a possible means of identification.https://digitalcommons.library.umaine.edu/aes_techbulletin/1160/thumbnail.jp

TB128: Beauveria bassiana for Control of Colorado Potato Beetle (Coleoptera: Chrysomelidae) in Maine

Beauveria bassiana (Balsamo) Vuill. (Bb), a fungal pathogen of the Colorado potato beetle has been used to control CPB in Europe. Preliminary studies in the United States gave promising results for CPB control by using the fungus. Based on these studies, a three-year pilot program was initiated to evaluate the potential for using Bb o control the Colorado potato beetle in the U.S. We report herein on the results obtained in southern Maine from using this mycoinsecticide to control the beetle.https://digitalcommons.library.umaine.edu/aes_techbulletin/1064/thumbnail.jp

TB83: Insecticidal Control of Potato Infesting Aphids in Northeastern Maine

Aphid populations for the growing seasons of 1970, 1971, and 197 2 were variable. It is possible, however, to rate the efficacy of the various insecticides tested in controlling potato-infesting aphids in northeastern Maine. Soil applications of aldicarb and DS 15,647 and foliar application of acephate were the most effective materials tested. The insecticides phosmet (foliar) and phoxim (soil) did not provide much protection against potato-infesting aphids in these tests. Bayer 77,049, parathion, Penick SBP 1382, Sandoz-Wander 52,139 and Uniroyal 840 did not provide effective control of potato-infesting aphids at the rates used in these tests. All other insecticides tested adequately controlled aphid populations, but their effects on the spread of leaf roll varied. Some of the materials tested were experimental materials and not all are available for commercial use.https://digitalcommons.library.umaine.edu/aes_techbulletin/1112/thumbnail.jp

TB55: Food Lists of Hippodamia (Coleoptera: Coccinellidae)

Food lists for Hippodamia iredecimpunctata (Linnaeus) and the genus Hippodamia as reported in the literature are given. A complete list of citations is included.https://digitalcommons.library.umaine.edu/aes_techbulletin/1150/thumbnail.jp