Physical Sciences and Mathematics Commons^™

A Survey For Very Short-Period Planets In The Kepler Data, Brian Jackson, Christopher C. Stark, Elisabeth R. Adams, John Chambers, Drake Deming

Brian Jackson

We conducted a search for very short-period transiting objects in the publicly available Kepler data set. Our preliminary survey has revealed four planetary candidates, all with orbital periods less than 12 hr. We have analyzed the data for these candidates using photometric models that include transit light curves, ellipsoidal variations, and secondary eclipses to constrain the candidates’ radii, masses, and effective temperatures. Even with masses of only a few Earth masses, the candidates’ short periods mean that they may induce stellar radial velocity signals (a few m s−1) detectable by currently operating facilities. The origins of such short-period planets are …

The Unexpectedly Bright Comet C/2012 F6 (Lemmon) Unveiled At Near-Infrared Wavelengths, Lucas Paganini, Michael A. Disanti, Michael J. Mumma, Geronimo L. Villanueva, Boncho P. Bonev, Jacqueline V. Keane, Erika L. Gibb, Hermann Boehnhardt, Karen J. Meech

Erika Gibb

Two Suns In The Sky: Stellar Multiplicity Influence On Planet Formation, Ji Wang, Debra Fischer

Debra A Fischer

We found that a planet is less likely to exist around a binary star, and thus Tatooine may be just a dream.

Recurrent Geomagnetic Storms And Relativistic Electron Enhancements In The Outer Magnetosphere: Istp Coordinated Measurements, D N. Baker, X Li, Niescja E. Turner, J H. Allen, L F. Bargatze, J B. Blake, R B. Sheldon, H E. Spence, R D. Belian, G D. Reeves, S G. Kanekal, B Klecker, R P. Lepping, K Ogilvie, R A. Mewaldt, T Onsager, H J. Singer, G Rostoker

Niescja E. Turner

New, coordinated measurements from the International Solar-Terrestrial Physics (ISTP) constellation of spacecraft are presented to show the causes and effects of recurrent geomagnetic activity during recent solar minimum conditions. It is found using WIND and POLAR data that even for modest geomagnetic storms, relativistic electron fluxes are strongly and rapidly enhanced within the outer radiation zone of the Earth's magnetosphere. Solar wind data are utilized to identify the drivers of magnetospheric acceleration processes. Yohkoh solar soft X-ray data are also used to identify the solar coronal holes that produce the high-speed solar wind streams which, in turn, cause the recurrent …

Solar Wind-Magnetosphere Coupling During An Isolated Substorm Event: A Multispacecraft Istp Study, T I. Pulkkinen, D N. Baker, Niescja E. Turner, H J. Singer, L A. Frank, J B. Sigwarth, J Scudder, R Anderson, S Kokubun, R Nakamura, T Mukai, J B. Blake, C T. Russell, H Kawano, F Mozer, J A. Slavin

Niescja E. Turner

Multispacecraft data from the upstream solar wind, polar cusp, and inner magnetotail are used to show that the polar ionosphere responds within a few minutes to a southward IMF turning, whereas the inner tail signatures are visible within ten min from the southward turning. Comparison of two subsequent substorm onsets, one during southward and the other during northward IMF, demonstrates the dependence of the expansion phase characteristics on the external driving conditions. Both onsets are shown to have initiated in the midtail, with signatures in the inner tail and auroral oval following a few minutes later.

Magnetospheric Response Times Following Southward Imf Turnings, Niescja E. Turner, D N. Baker, T I. Pulkkinen, H J. Singer, F Mozer

Niescja E. Turner

No abstract provided.

Seasonal And Diurnal Variation Of Geomagnetic Activity: Revised Dst Versus External Drivers, L V.T Hakkinen, T I. Pulkkinen, R J. Pirjola, H Nevanlinna, E I. Tanskanen, Niescja E. Turner

Niescja E. Turner

Daily and seasonal variability of long time series of magnetometer data from Dst stations is examined. Each station separately shows a local minimum of horizontal magnetic component near 18 local time (LT) and weakest activity near 06 LT. The stations were found to have different baselines such that the average levels of activity differed by about 10 nT. This effect was corrected for by introducing a new “base method” for the elimination of the secular variation. This changed the seasonal variability of the Dst index by about 3 nT. The hemispheric differences between the annual variation (larger activity during local …

Energetics Of Magnetic Storms Driven By Corotating Interaction Regions: A Study Of Geoeffectiveness, Niescja E. Turner, E J. Mitchell, D J. Knipp, B A. Emery

Niescja E. Turner

We investigate the energetics of magnetic storms associated with corotating interaction regions (CIRs). We analyze 24 storms driven by CIRs and compare to 18 driven by ejecta-related events to determine how they differ in overall properties and in particular in their distribution of energy. To compare these different types of events, we look at events with comparable input parameters such as the epsilon parameter and note the properties of the resulting storms. We estimate the energy output by looking at the ring current energy along with ionospheric Joule heating derived from the PC and Dst indices. We also include the …

A New Method To Describe Image Theory For An Imperfect Conductor, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

Problem statement: Modify the equations associated with image theory in order to account for perfect and imperfect conductors. Approach: A novel approach for describing the application of image theory for an imperfect conductive surface was presented. The method presented here purposely downplays the physics of how image theory was employed to account for a charge which is in the presence of an imperfect conductive surface. In turn, it adopted an approach which focused on the geometry that existed between the charged particle and surface ground. In doing so, the proposed method formulated a solution that had minimized the complexity of …

A New Method For Describing The Horizontal Electric Field Induced By A Lightning Strike Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

No abstract provided.

Effects Of Different Geomagnetic Storm Drivers On The Ring Current: Crcm Results, W D. Cramer, Niescja E. Turner, M C. Fok, N Y. Buzulukova

Niescja E. Turner

The storm-time magnetic disturbance at the Earth's equator, as commonly measured by the Dst index, is induced by currents in the near-Earth magnetosphere. The ring current is generally considered the most important contributor, but other magnetospheric currents have also been found to have significant effects. Of the two main types of solar geomagnetic storm drivers, Coronal Mass Ejections (CMEs) tend to have a much greater impact on Dst than Corotating Interaction Regions (CIRs). Ring current models have been found to underestimate Dst, particularly during storms driven by CIRs. One possible explanation is that the models neglect to handle some aspect …

Timing Of Substorm-Associated Auroral Oscillations, P Martin, Niescja E. Turner, J Wanliss

Niescja E. Turner

Previous studies have shown that auroral luminosity oscillations are often associated with substorms. Here we examine photometer data for the magnetospheric substorm on April 1, 2000 (expansive phase onset at 0525 UT) to study the detailed timing of the auroral oscillations relative to onset. Accurate timing information for the periodicities in the photometer data were determined using the wavelet transform. We find that the oscillations occur primarily during the recovery phase. Copyright © The Society of Geomagnetism and Earth

The Horizontal Electric Field Induced By A Lightning Return Stroke, S L. Meredith, S K. Earles, Niescja E. Turner

Niescja E. Turner

Problem statement: Develop a new formula which describes the horizontal electric field induced by a lightning return stroke in contact with an imperfect conductive surface. Approach: A new method for describing the horizontal electric field induced by a lightning return stroke will be presented. The method presented here had utilized an approach which purposely downplayed the physics of how image theory was employed in the presence of an imperfect conductive surface. It did so by adopting a technique which had focused on the geometry that existed between the lightning channel and surface ground. In doing so, new expressions for surface …

Maintenance Of Circulation Anomalies During The 1988 Drought And 1993 Floods Over The United States, Alan Z. Liu, Mingfang Ting, Hailan Wang

Alan Z Liu

The large-scale circulation anomalies associated with the 1988 drought and the 1993 floods are investigated with the National Centers for Environmental Prediction Reanalysis data and a linear stationary wave model. The transient vorticity and thermal forcings are explicitly calculated and the diabatic heating is derived as a residual in the thermodynamic energy equation. Using the April–June (AMJ) data for 1988, and June–August (JJA) data for 1993, the linear stationary wave model is able to reproduce the main features of the geopotential height anomaly for the two seasons when all forcings are included. This provides a basis for further investigation of …

Detection Of Ch4 In The Gv Tau N Protoplanetary Disk, Erika L. Gibb, David Horne

Erika Gibb

The Xmm-Newton Epic X-Ray Light Curve Analysis Of Wr 6., Richard Ignace, K. G. Gayley, W.-R. Hamann, D. P. Huenemoerder, L. M. Oskinova, A. M. T. Pollock, M. Mcfall

Richard Ignace

We obtained four pointings of over 100 ks each of the well-studied Wolf-Rayet star WR 6 with the XMM-Newton satellite. With a first paper emphasizing the results of spectral analysis, this follow-up highlights the X-ray variability clearly detected in all four pointings. However, phased light curves fail to confirm obvious cyclic behavior on the well-established 3.766 d period widely found at longer wavelengths. The data are of such quality that we were able to conduct a search for "event clustering" in the arrival times of X-ray photons. However, we fail to detect any such clustering. One possibility is that X-rays …

Multiwavelength Observations Of The Ss 433 Jets, Herman L. Marshall, Claude R. Canizares, Todd Hillwig, Amy Mioduszewski, Michael Rupen, Norbert S. Schulz, Michael Nowak, Sebastian Heinz

Todd Hillwig

Conformal Tensors Via Lovelock Gravity, David Kastor

David Kastor

Constructs from conformal geometry are important in low dimensional gravity models, while in higher dimensions the higher curvature interactions of Lovelock gravity are similarly prominent. Considering conformal invariance in the context of Lovelock gravity leads to natural, higher-curvature generalizations of the Weyl, Schouten, Cotton and Bach tensors, with properties that straightforwardly extend those of their familiar counterparts. As a first application, we introduce a new set of conformally invariant gravity theories in D=4k dimensions, based on the squares of the higher curvature Weyl tensors.

Measurement Of Spin-Orbit Misalignment And Nodal Precession For The Planet Around Pre-Main-Sequence Star Ptfo 8-8695 From Gravity Darkening, Jason W. Barnes, Julian C. Van Eyken, Brian K. Jackson, David R. Ciardi, Jonathan J. Fortney

Brian Jackson

PTFO 8-8695b represents the first transiting exoplanet candidate orbiting a pre-main-sequence star (van Eyken et al. 2012, ApJ, 755, 42). We find that the unusual lightcurve shapes of PTFO 8-8695 can be explained by transits of a planet across an oblate, gravity-darkened stellar disk. We develop a theoretical framework for understanding precession of a planetary orbit’s ascending node for the case when the stellar rotational angular momentum and the planetary orbital angular momentum are comparable in magnitude. We then implement those ideas to simultaneously and self-consistently fit two separate lightcurves observed in 2009 December and 2010 December. Our two self-consistent …

On The Universality Of Inner Black Hole Mechanics And Higher Curvature Gravity, Alejandra Castro, Nima Dehmami, Gaston Giribet, David Kastor

David Kastor

Black holes are famous for their universal behavior. New thermodynamic relations have been found recently for the product of gravitational entropies over all the horizons of a given stationary black hole. This product has been found to be independent of the mass for all such solutions of Einstein-Maxwell theory in d=4,5. We study the universality of this mass independence by introducing a number of possible higher curvature corrections to the gravitational action. We consider finite temperature black holes with both asymptotically flat and (A)dS boundary conditions. Although we find examples for which mass independence of the horizon entropy product continues …

Precise Radial Velocities Of Giant Stars V. A Brown Dwarf And A Planet Orbiting The K Giant Stars Tau Geminorum And 91 Aquarii, David Mitchell

David Mitchell

Aims. We aim to detect and characterize substellar companions to K giant stars to further our knowledge of planet formation and

stellar evolution of intermediate-mass stars.

Methods. For more than a decade we have used Doppler spectroscopy to acquire high-precision radial velocity measurements of

K giant stars. All data for this survey were taken at Lick Observatory. Our survey includes 373 G and K giants. Radial velocity data

showing periodic variations were fitted with Keplerian orbits using a χ2 minimization technique.

Results. We report the presence of two substellar companions to the K giant stars τ Gem and 91 Aqr. …

High Precision K-Shell Photoabsorption Cross Sections For Atomic Oxygen: Experiment And Theory, Brendan M. Mclaughlin, C P. Ballance, K P. Bowen, D J. Gardenghi, Wayne C. Stolte

Wayne C. Stolte

Photoabsorption of atomic oxygen in the energy region below the 1s −1 threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/ΔE ≈ 4250 ± 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 ± 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the …

Gravitational Tension And Thermodynamics Of Planar Ads Spacetimes, Basem M. El-Menoufi, Benjamin Ett, David Kastor, Jennie Traschen

David Kastor

We derive new thermodynamic relations for asymptotically planar AdS black hole and soliton solutions. In addition to the ADM mass, these spacetimes are characterized by gravitational tensions in each of the planar spatial directions. We show that with planar AdS asymptotics, the sum of the ADM mass and tensions necessarily vanishes, as one would expect from the AdS /CFT correspondence. Each Killing vector of such a spacetime leads to a Smarr formula relating the ADM mass and tensions, the black hole horizon and soliton bubble areas, and a set of thermodynamic volumes that arise due to the non-vanishing cosmological constant. …

Spectro-Astrometry Of Water In Dr Tauri, Logan R. Brown, Matthew R. Troutman, Erika L. Gibb

Erika Gibb

Thermodynamic Volumes And Isoperimetric Inequalities For De Sitter Black Holes, Brian P. Dolan, David Kastor, David KubiznˇA´K, Robert B. Mann, Jennie Traschen

David Kastor

We consider the thermodynamics of rotating and charged asymptotically de Sitter black holes. Using Hamiltonian perturbation theory techniques, we derive three different first law relations including variations in the cosmological constant, and associated Smarr formulas that are satisfied by such spacetimes. Each first law introduces a different thermodynamic volume conjugate to the cosmological constant. We examine the relation between these thermodynamic volumes and associated geometric volumes in a number of examples, including Kerr-dS black holes in all dimensions and Kerr-Newman-dS black holes in D=4. We also show that the Chong-Cvetic-Lu-Pope solution of D=5 minimal supergravity, analytically continued to positive cosmological …

Wireless Transmission Network : A Imagine, Radhey Shyam Meena Engineer, Neeraj Kumar Garg Asst.Prof

Radhey Shyam Meena

World cannot be imagined without electrical power. Generally the power is transmitted through transmission networks. This paper describes an original idea to eradicate the hazardous usage of electrical wires which involve lot of confusion in particularly organizing them. Imagine a future in which wireless power transfer is feasible: cell phones, household robots, mp3 players, laptop computers and other portable electronic devices capable of charging themselves without ever being plugged in freeing us from that final ubiquitous power wire. This paper includes the techniques of transmitting power without using wires with an efficiency of about 95% with non-radioactivemethods. In this paper …

Simulating Exoplanet Detection Of Kepler Via Monte-Carlo Techniques, Manuel Marcano, Mario Yuuji Harper

Mario Yuuji Harper

The Kepler mission was launched in 2009 with the intent to find earth-like planets around other star systems. Since it's launch, the number of known (and suspected) exoplanets have increased substantially from 200 to 3000. With this increase in data now available, we have chosen to model through a monte-carlo simulation, the possibility of being able to see exoplanets in a random part of the sky (using the parameters of the Kepler spacecraft). We show that there is a 0.18 to 0.01 percent chance of being able to detect exoplanets.

Battery Energy Storage System In Solar Power Generation, Radhey Shyam Meena Er., Deepa Sharma

Radhey Shyam Meena

Grid-connected solar PV dramatically changes the load profile of an electric utility customer. The expected widespread adoption of solar generation by customers on the distribution system poses significant challenges to system operators both in transient and steady state operation, from issues including voltage swings, sudden weather-induced changes in generation, and legacy protective devices designed with one-way power flow in mind

Quantifying Night Sky Fluctuations: Striving For A Multi-Messenger Astronomy, Rachel K. Nydegger, Shane L. Larson Ph.D.

Rachel Nydegger Rozum

With LIGO coming back online soon, astronomers are attempting to solve the problems involved with coupling gravitational observations with electromagnetic telescope observations. To do this, my project aims to create all-sky surveys to characterize natural variability to reduce "false-alarm" rates in detections of gravitational emissions.

Modeling Spiral Galaxy Surface Luminosity To Explain Non-Uniform Inclination Distributions, Jordan C. Rozum, Shane L. Larson

Jordan Rozum

The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and ISM density distributions. The luminous component is integrated along a particular line of sight, thus …