Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy Commons

Open Access. Powered by Scholars. Published by Universities.®

2,705 Full-Text Articles 6,824 Authors 163,116 Downloads 112 Institutions

All Articles in Astrophysics and Astronomy

Faceted Search

2,705 full-text articles. Page 1 of 57.

Rotation Lightcurves Of Small Jovian Trojan Asteroids, Linda French, Robert D. Stephens, Daniel Coley, Lawrence H. Wasserman, Jennifer Sieben 2015 Illinois Wesleyan University

Rotation Lightcurves Of Small Jovian Trojan Asteroids, Linda French, Robert D. Stephens, Daniel Coley, Lawrence H. Wasserman, Jennifer Sieben

Linda French

Several lines of evidence support a common origin for, and possible hereditary link between, cometary nuclei and Jovian Trojan asteroids. Due to their distance and low albedos, few comet-sized Trojans have been studied. We present new lightcurve information for 19 Trojans ≲ 30 km in diameter, more than doubling the number of objects in this size range for which some rotation information is known. The minimum densities for objects with complete lightcurves are estimated and are found to be comparable to those measured for cometary nuclei. A significant fraction (~40%) of this observed small Trojan population rotates slowly (P > 24 hours ...


Analysis And Comparison Of Physical Properties And Morphology Of Impact Melt Flows On Venus And The Moon To Determine Atmospheric Controls, Christine Elizabeth Dong 2015 Bates College

Analysis And Comparison Of Physical Properties And Morphology Of Impact Melt Flows On Venus And The Moon To Determine Atmospheric Controls, Christine Elizabeth Dong

Geology Theses

Impact melt flows form when target material melted by an impact breaches the rim of the impact crater. The melt flows out and away from the crater, forming a lava flow. Such flows have been identified on Venus and the Moon by previous studies. This study aims to document impact melt flows on these two bodies to determine the differences, if any, between them, and to ascertain whether these differences are due to atmospheric conditions. Previously recorded morphological data from Robert Herrick of the Lunar and Planetary Institute and Neish et al. (2014) are used in conjunction with S-band (12 ...


A Photometric Study Of The Eclipsing Binary Star Uv Lyncis, Edward J. Michaels 2015 Stephen F Austin State University, Department of Physics and Astronomy

A Photometric Study Of The Eclipsing Binary Star Uv Lyncis, Edward J. Michaels

Bright Ideas Conference

UV Lyncis is a short period, over contact eclipsing binary star. These stars are physically in contact with each other, sharing a common atmosphere. Photometric observations were made on 10 nights in February and March 2014 using the 0.3 meter robotic telescope and a CCD science imager at the Waffelow Creek Observatory. 3051 images were acquired, calibrated and then reduced to record the changing brightness as the two stars orbited and eclipsed each other. Data collected resulted in complete light curves in 5 band passes and several times of minima. A period analysis confirmed previous studies that the orbital ...


Stellar Spectroscopy: New Methods And Insights, Sanaz S. Golriz 2015 The University of Western Ontario

Stellar Spectroscopy: New Methods And Insights, Sanaz S. Golriz

University of Western Ontario - Electronic Thesis and Dissertation Repository

The study of the chemical evolution of stars is of crucial importance since they play a major role in the enrichment of the chemistry of the universe. Throughout their lifetime, stars undergo several processes that can alter their chemistry. Gradually, the nucleosynthesis products from the interior of the star are radiatively and convectively levitated and mixed with the upper layers of the atmosphere. In the later stages of their evolution, low to intermediate mass stars (0.8-8.0~M☉) eject a significant fraction of these nucleosynthesis products, resulting in a circumstellar envelope of gas and dust around the central star ...


Supernatural Cosmic Origins: Challenging The Reigning Paradigm, Rachel Blattner 2015 Liberty University

Supernatural Cosmic Origins: Challenging The Reigning Paradigm, Rachel Blattner

Senior Honors Theses

Contemporary scientific study primarily uses a paradigm based upon naturalism, materialism, and empiricism on which to base research. The widely accepted cosmological model the big bang theory adheres to this paradigm. Despite many weaknesses in this model and in the paradigm itself, researchers continue to favor the modification of the accepted model over the adoption of other more comprehensive models. The paradigm from which the models proposed by Russell Humphries, John Hartnett, and Jason Lisle come justifies the six-day creation young-earth biblical account and better fits observational evidence with fewer arbitrary assumptions than the paradigm from which the big bang ...


The Ptolemaic System: A Detailed Synopsis, John Cramer Dr. 2015 Kennesaw State University

The Ptolemaic System: A Detailed Synopsis, John Cramer Dr.

Oglethorpe Journal of Undergraduate Research

The Ptolemaic System, constructed by Claudius Ptolemeus (the Latin form of his name), was the most influential of all Earth centered cosmological systems. His ingenious and creative work is primarily recorded in his book The Mathematical Systematic Treatise which the Arabs characterized as “the greatest” and, in so doing, gave the book its most used name, Almagest.


The Copernican System: A Detailed Synopsis, John Cramer Dr. 2015 Kennesaw State University

The Copernican System: A Detailed Synopsis, John Cramer Dr.

Oglethorpe Journal of Undergraduate Research

Dissatisfied with the problems of the geocentric system inherited from Claudius Ptolemy, Nicholas Copernicus began the change from geocentrism to heliocentrism. His eponymous system was expounded first in the Commentariolus (written about 1508 and circulated privately in manuscript form) and then more fully and finally in his book, De Revolutionibus Orbium Coelestium (On the Revolutions of the Celestial Orbs) published as he lay dying in 1543.


Methods And Results Toward Measuring Magnetic Fields In Star-Forming Regions, Scott C. Jones 2015 The University of Western Ontario

Protolunar Disk Evolution And The Depletion Of Volatile Elements In The Moon, Robin M. Canup, Channon Visscher, Julien Salmon, Bruce Fegley Jr. 2015 Southwest Research Institute

Protolunar Disk Evolution And The Depletion Of Volatile Elements In The Moon, Robin M. Canup, Channon Visscher, Julien Salmon, Bruce Fegley Jr.

Faculty Work: Comprehensive List

We explore how the evolution of the protolunar disk could lead to a depletion in K, Na, and Zn in the Moon relative to Earth even in the absence of escape.


The Riemann Curvature Tensor, Its Invariants, And Their Use In The Classification Of Spacetimes, Jesse Hicks 2015 Utah State University

The Riemann Curvature Tensor, Its Invariants, And Their Use In The Classification Of Spacetimes, Jesse Hicks

Presentations and Publications

The equivalence problem in general relativity is to determine whether two solutions of the Einstein field equations are isometric. Petrov has given a classification of metrics according to their isometry algebras. This talk discusses the use of the Petrov classification scheme, together with the use of scalar curvature invariants, to address the equivalence problem. These are the slides for a presentation at the Mathematics Association of America Spring 2015 conference at Brigham Young University.


Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos 2015 Utah State University

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Presentations and Publications

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and elec- tromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equa- tions are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Ge- ometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and for- mulas for constructing ...


Radio Emission Toward Regions Of Massive Star Formation In The Large Magellanic Cloud, Adam Johanson 2015 Brigham Young University - Provo

Radio Emission Toward Regions Of Massive Star Formation In The Large Magellanic Cloud, Adam Johanson

All Theses and Dissertations

Four regions of massive star formation in the Large Magellanic Cloud (LMC) were observed for water and methanol maser emission and radio continuum emission. A total of 42 radio detections were made including 27 new radio sources, four water masers, and eight compact HII regions. The lobes of a radio galaxy were resolved for the first time, and the host galaxy identified. Seven sources were associated with known massive young stellar objects (YSOs). A multi-wavelength analysis using both the infrared and radio spectrum was used to characterize the sources. Mid-infrared color-magnitude selection criteria for ultracompact HII (UCHII) regions in the ...


The Jcmt Gould Belt Survey: Evidence For Radiative Heating In Serpens Mwc 297 And Its Influence On Local Star Formation, D. Rumble, J. Hatchell, R. A. Gutermuth, H. Kirk, J. Buckle, S.F. Beaulieu, D.S. Berry, H. Broekhoven-Fiene, M.J. Currie, M. Fich, T. Jenness, D. Johnstone, J.C. Mottram, D. Nutter, K. Pattle, J.E. Pineda, C. Quinn, C. Salji, S. Tisi, S. Walker-Smith, J. Di Francesco, M.R. Hogerheijde, D. Ward-Thompson, L.E. Allen, L.A. Cieza, M.M. Dunham, P.M. Harvey, K.R. Stapelfeldt, P. Bastien, H. Bunter, M. Chen, A. Chrysostomou, S. Coude, C.J. Davis, E. Drabek-Maunder, A. Duarte-Cabral, J. Greaves, J. Gregson, W. Holland, G. Joncas, J.M. Kirk, L.B.G. Knee, S. Mairs, K. Marsh, B.C. Matthews, G. Moriarty-Schieven, J. Rawlings, J. Richer, D. Robertson, E. Rosolowsky, S. Sadavoy, H. Thomas, N. Tothill, S. Viti, G.J. White, C.D. Wilson, J. Wouterloot, J. Yates, M. Zhu 2015 University of Massachusetts - Amherst

The Jcmt Gould Belt Survey: Evidence For Radiative Heating In Serpens Mwc 297 And Its Influence On Local Star Formation, D. Rumble, J. Hatchell, R. A. Gutermuth, H. Kirk, J. Buckle, S.F. Beaulieu, D.S. Berry, H. Broekhoven-Fiene, M.J. Currie, M. Fich, T. Jenness, D. Johnstone, J.C. Mottram, D. Nutter, K. Pattle, J.E. Pineda, C. Quinn, C. Salji, S. Tisi, S. Walker-Smith, J. Di Francesco, M.R. Hogerheijde, D. Ward-Thompson, L.E. Allen, L.A. Cieza, M.M. Dunham, P.M. Harvey, K.R. Stapelfeldt, P. Bastien, H. Bunter, M. Chen, A. Chrysostomou, S. Coude, C.J. Davis, E. Drabek-Maunder, A. Duarte-Cabral, J. Greaves, J. Gregson, W. Holland, G. Joncas, J.M. Kirk, L.B.G. Knee, S. Mairs, K. Marsh, B.C. Matthews, G. Moriarty-Schieven, J. Rawlings, J. Richer, D. Robertson, E. Rosolowsky, S. Sadavoy, H. Thomas, N. Tothill, S. Viti, G.J. White, C.D. Wilson, J. Wouterloot, J. Yates, M. Zhu

Robert A. Gutermuth

We present SCUBA-2 450 and 850 μm observations of the Serpens MWC 297 region, part of the James Clerk Maxwell Telescope (JCMT) Gould Belt Survey of nearby star-forming regions. Simulations suggest that radiative feedback influences the star formation process and we investigate observational evidence for this by constructing temperature maps. Maps are derived from the ratio of SCUBA-2 fluxes and a two-component model of the JCMT beam for a fixed dust opacity spectral index of β = 1.8. Within 40 arcsec of the B1.5Ve Herbig star MWC 297, the submillimetre fluxes are contaminated by free–free emission with a ...


Empyreal Radiance: An Application Of Sonification In The Field Of Astrophysics, Ryan Loth 2015 Otterbein University

Empyreal Radiance: An Application Of Sonification In The Field Of Astrophysics, Ryan Loth

Distinction Papers

Broadly, this paper discusses the application of sonification and its potential for increasing knowledge. The paper is broken up into three sections: the theory of sonification, sonification for artistic purposes, and lastly an extensive look at one process of sonification dealing with solar winds in space. Concerning the theory of sonification, the paper will divulge into the process of sonification and ask questions about the limitations of it as well. The second section discusses how sonification is a way to build the curiosity of not just scientists, but also the general public. The final section addresses my composition Empyreal Radiance ...


Rationality Of The Spectral Action For Robertson-Walker Metrics And The Geometry Of The Determinant Line Bundle For The Noncommutative Two Torus, Asghar Ghorbanpour 2015 The University of Western Ontario

Rationality Of The Spectral Action For Robertson-Walker Metrics And The Geometry Of The Determinant Line Bundle For The Noncommutative Two Torus, Asghar Ghorbanpour

University of Western Ontario - Electronic Thesis and Dissertation Repository

In noncommutative geometry, the geometry of a space is given via a spectral triple $(\mathcal{A,H},D)$. Geometric information, in this approach, is encoded in the spectrum of $D$ and to extract them, one should study spectral functions such as the heat trace $\Tr (e^{-tD^2})$, the spectral zeta function $\Tr(|D|^{-s})$ and the spectral action functional, $\Tr f(D/\Lambda)$.

The main focus of this thesis is on the methods and tools that can be used to extract the spectral information. Applying the pseudodifferential calculus and the heat trace techniques, in addition to computing the newer ...


On The Detection Of Exoplanets Via Radial Velocity Doppler Spectroscopy, Joseph P. Glaser 2015 Cleveland State University

On The Detection Of Exoplanets Via Radial Velocity Doppler Spectroscopy, Joseph P. Glaser

The Downtown Review

Since the discovery of the first exoplanet occurred in the late 1980s, physicists and astronomers have confirmed the existence of over 1783 planets orbiting other stars. Over the years, several methods have been developed for detecting these celestial systems, but none has thus far been more successful than the use of Radial Velocity Doppler Spectroscopy. As such, this paper attempts to break down the barriers placed before new entries into the field by detailing the theoretical premise and experimental process of this most successful technique. The content enclosed is geared for the senior undergraduate student with some knowledge of vector-based ...


A 24Μm Point Source Catalog Of The Galactic Plane From Spitzer/Mipsgal, R. A. Gutermuth, Mark Heyer 2015 University of Massachusetts - Amherst

A 24Μm Point Source Catalog Of The Galactic Plane From Spitzer/Mipsgal, R. A. Gutermuth, Mark Heyer

Robert A. Gutermuth

In this contribution, we describe the applied methods to construct a 24 μm based point source catalog derived from the image data of the MIPSGAL 24 μm Galactic Plane Survey and the corresponding data products. The high quality catalog product contains 933,818 sources, with a total of 1,353,228 in the full archive catalog. The source tables include positional and photometric information derived from the 24 μm images, source quality and confusion flags, and counterpart photometry from matched 2MASS, GLIMPSE, and WISE point sources. Completeness decay data cubes are constructed at 1' angular resolution that describe the varying ...


The Formation Of The Trajectories Of The Planets Of The Solar System, Vildyan Yanbikov 2015 Yanbikov Vildyan Shavkyatovich

The Formation Of The Trajectories Of The Planets Of The Solar System, Vildyan Yanbikov

Vildyan Yanbikov

Процесс превращения круговой орбите планеты по эллиптической. Процесс превращения эллиптической орбите вокруг Солнца (прецессия перигелия планеты).


Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos 2015 Department of Physics, Utah State University

Geometrization Conditions For Perfect Fluids, Scalar Fields, And Electromagnetic Fields, Charles G. Torre, Dionisios Krongos

Charles G. Torre

Rainich-type conditions giving a spacetime “geometrization” of matter fields in general relativity are reviewed and extended. Three types of matter are considered: perfect fluids, scalar fields, and elec- tromagnetic fields. Necessary and sufficient conditions on a spacetime metric for it to be part of a perfect fluid solution of the Einstein equa- tions are given. Formulas for constructing the fluid from the metric are obtained. All fluid results hold for any spacetime dimension. Ge- ometric conditions on a metric which are necessary and sufficient for it to define a solution of the Einstein-scalar field equations and for- mulas for constructing ...


Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, Frank Prendergast, Tom Ray 2015 Dublin Institute of Technology

Alignment Of The Western And Eastern Passage Tombs At Knowth Tomb 1, Frank Prendergast, Tom Ray

Book/Book Chapter

This report presents a summary account of two surveys undertaken by the authors to determine and interpret the alignments of the western and eastern passage tombs at Knowth, Co. Meath. The findings indicate that contrary to earlier suggestions, the eastern passage and the western passage (inner and outer) are not aligned towards sunrise and sunset respectively at the period of the vernal and autumnal equinoxes.


Digital Commons powered by bepress