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

Astrophysics and Astronomy Commons

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

5122 Full-Text Articles 12284 Authors 339281 Downloads 151 Institutions

All Articles in Astrophysics and Astronomy

Faceted Search

5122 full-text articles. Page 1 of 148.

Book Review: Chandra's Cosmos: Dark Matter, Black Holes, And Other Wonders Revealed By Nasa's Premier X-Ray Observatory, T. D. Oswalt 2017 Embry-Riddle Aeronautical University

Book Review: Chandra's Cosmos: Dark Matter, Black Holes, And Other Wonders Revealed By Nasa's Premier X-Ray Observatory, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Chandra's cosmos: dark matter, black holes, and other wonders revealed by NASA's premier X-ray observatory by Wallace H. Tucker. Smithsonian Books, 2017. 266p bibl index ISBN 9781588345875, $29.95; ISBN 9781588345882 ebook, contact publiser for price.


Creating An Experimental Learning And Research Driven Spacesuit Lab For Erau, Ryan L. Kobrick, Erik Seedhouse 2017 Embry-Riddle Aeronautical University

Creating An Experimental Learning And Research Driven Spacesuit Lab For Erau, Ryan L. Kobrick, Erik Seedhouse

Ryan L. Kobrick

This paper evaluates key functional data parameters that must be considered for suborbital spaceflight participants wearing pressurized suits for intravehicular activity (IVA). Data parameters of an analog spacesuit worn in an analog flight environment were obtained from 40 civilian participants using the Suborbital Space Flight Simulator (SSFS) at Embry-Riddle Aeronautical University (ERAU) while donning Final Frontier Design’s (FFD) fully pressurized third-generation spacesuit as part of their training for Project PoSSUM (the Polar Suborbital Science in the Upper Mesosphere Project). The physiological data collected included: blood pressure, electrocardiograms, heart rate, grip strength, and skin temperature. These parameters were measured using ...


Effect Of Observational Cadence On Orbit Determination For Synthetic Near-Earth Objects, Thomas G. Endicott 2017 University of Massachusetts Boston

Effect Of Observational Cadence On Orbit Determination For Synthetic Near-Earth Objects, Thomas G. Endicott

Graduate Masters Theses

Near-Earth Objects (NEOs) are generally small, dark, and fast-moving. Multiple observations over time are necessary to constrain NEO orbits. Orbits based on observational data are inherently uncertain. Here we describe code written in Python and Fortran used to generate synthetic asteroids and compare calculated orbital fit based on noisy ephemeris using the a distance criteria, D-value. Observational sessions separated by more than one month produce very good orbital fits (low D-values) even at the highest noise level. Daily observational sessions show the highest D-values, as expected, since observed points on the orbital ellipse are not well separated. D-value is closely ...


"Blinded By The Lines: Mid-Ir Spectra Of Mira Variables Taken With Spitzer", Dana Baylis-Aguirre, Michelle J. Creech-Eakman, Donald G. Luttermoser, Tina Gueth 2017 New Mexico Institute of Mining and Technology

"Blinded By The Lines: Mid-Ir Spectra Of Mira Variables Taken With Spitzer", Dana Baylis-Aguirre, Michelle J. Creech-Eakman, Donald G. Luttermoser, Tina Gueth

Donald G. Luttermoser

We present preliminary analysis of mid-infrared spectra of M-type and C-type Mira variables. Due to the brightness of this sample, it is straightforward to monitor changes with phase in the infrared spectral features of these regular pulsators. We have spectra of 25 Mira variables, taken with phase, using the Spitzer Infrared Spectrograph (IRS) high-resolution module. Each star has multiple spectra obtained over a one-year period from 2008-09. This is a rich, unique data set due to multiple observations of each star and the high signal-to-noise ratio from quick exposure times to prevent saturation of the IRS instrument. This paper focuses ...


Observing Kelt Candidate Objects In The Search For Transiting Exoplanets, Maria Martinez 2017 Brigham Young University

Observing Kelt Candidate Objects In The Search For Transiting Exoplanets, Maria Martinez

All Student Publications

The main goal of this project was to learn how to participate and be a part of a real observational team. We worked with the KELT exoplanet search project. While working with the KELT project we hoped to be able to confirm a candidate object as a planet. However, trying to discover a transiting planet was not our main goal for the summer. In addition, we also set out to learn how to work in an observatory, operate telescopes, and process data. The different objects we observed throughout the summer were not all determined to be transiting exoplanets, but we ...


Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura 2017 Brigham Young University

Developing Instrumentation For Fabricating And Characterizing Thin Film Aluminum Mirrors, P. Claire Segura

All Student Publications

The best material for constructing a mirror for a broad-bandwidth telescope that is also capable of reflecting EUV light is pure aluminum. In order to test how the reflectance of aluminum in the EUV range changes as it oxidizes, a system has been constructed that allows a thin aluminum mirror to be constructed inside of a vacuum, where its reflectance can then be tested immediately. Because the experiment must take place in a vacuum, it must also be controlled remotely through a computer program, which manages the mirror fabrication process as well as the collection and analysis of reflectance data ...


Oxidization Of Al And A-Si As A Protective Layer, Yhoshua Wug 2017 Brigham Young University

Oxidization Of Al And A-Si As A Protective Layer, Yhoshua Wug

All Student Publications

Arguably, the best chance to produce a IR-optical-UV-EUV mirror for a future space observatory is a multilayer mirror coated by a thin bare aluminum layer. Using an Al layer presents challenges that have to be overcome first. Al oxidizes rapidly as soon as it comes in contact with the atmosphere. One solution is to block the oxidation of Al by covering the mirror with a protective layer and remove it once the mirror is in space. freshly, deposited a-Si would be a good candidate for protecting the mirror. Removing it in space also presents some challenges. The best way to ...


Differential Photometry Of High Mass X-Ray Binaries And Be Stars And Determining Standard Stars, Anne Blackwell 2017 Brigham Young University

Differential Photometry Of High Mass X-Ray Binaries And Be Stars And Determining Standard Stars, Anne Blackwell

All Student Publications

Building off of the previously established Hα index (Joner & Hintz 2015), I use differential photometry to study high mass x-ray binaries and Be stars using the Hα index to define their level of activity. Specifically I focused of Cygnus X-1 and X Perseus. I took data on Cygnus X-1 (X Perseus will be studied later in the year) to look at its long and short term activity. Data analyzed using differential photometry is merged with previously collected spectroscopic data to show a seamless flow of results between techniques. I also defined the Hα values of 10 stars in the frame ...


Bringing Awe Down To Earth: Inspiring High Performance Through Positive Executive Coaching, Chad Thomas 2017 University of Pennsylvania

Bringing Awe Down To Earth: Inspiring High Performance Through Positive Executive Coaching, Chad Thomas

Master of Applied Positive Psychology (MAPP) Capstone Projects

What inspires and sustains high performance? Positive psychology, the scientific study of human strengths and well-being, provides evidence-based insights into the mechanisms of, and characteristics associated with, flourishing. Astronauts represent a paragon of high performance through the intensely focused preparation, passion, and perseverance required in their training and during space missions. This capstone draws on both scientific findings from positive psychology and insights from astronaut training to provide a unique lens for a positive executive coaching program. In addition to a review of relevant positive psychology research to illustrate the principles of this program, this capstone includes personal anecdotes and ...


Sources Of Gravity.Docx, Vildyan Yanbikov 2017 Yanbikov Vildyan Shavkyatovich

Sources Of Gravity.Docx, Vildyan Yanbikov

Vildyan Yanbikov

Computed coefficients of gravity. (gravitational constant) in the center and the surface of the Sun. The computed critical parameters. a slowly rotating neutron star. In her state of the instability (before it exploded). Checked the assumption about the rate of transmission of gravitational interactions. Using the given method it is possible to calculate the coefficient of gravity away from the powerful gravity source.                                                                  


Empty Universe.Docx, Vildyan Yanbikov 2017 Yanbikov Vildyan Shavkyatovich

Empty Universe.Docx, Vildyan Yanbikov

Vildyan Yanbikov

Calculated the speed of propagation of gravity in space. ( the speed of gravity waves). The computed gravitational constant for the “empty” space.


Evaluation Of Radiation And Design Criteria For A Lunar Habitat, Hayley E. Bower, Daniel Gomez, Antonio Bobet, Julio A. Ramirez, Shirley J. Dyke, H. Jay Melosh 2017 Purdue University

Evaluation Of Radiation And Design Criteria For A Lunar Habitat, Hayley E. Bower, Daniel Gomez, Antonio Bobet, Julio A. Ramirez, Shirley J. Dyke, H. Jay Melosh

The Summer Undergraduate Research Fellowship (SURF) Symposium

Extraterrestrial habitation has long been the object of science fiction, and experts in the fields of science and engineering have proposed many designs for a lunar base. The research conducted has focused on either structural stability, radiation protection, or meteorite-impact vulnerabilities, but rarely have these been considered together. The Resilient ExtraTerrestrial Habitats (RETH) project aims to design a lunar habitat from a hazards perspective, considering general degradation, meteorite impacts, seismic activity, radiation exposure, thermal extremes, and geomagnetic storms in addition to the physiological, psychological, and sociological aspects of astronauts living in such a habitat. Several members of the RETH team ...


An Upper Limit On The Tightening Of Galactic Spiral Arm Pitch Angle In Cosmic Time, Douglas William Shields 2017 University of Arkansas, Fayetteville

An Upper Limit On The Tightening Of Galactic Spiral Arm Pitch Angle In Cosmic Time, Douglas William Shields

Theses and Dissertations

We present Spirality, a novel method of measuring pitch angle by fitting galaxy images to spiral templates of known pitch. Using this algorithm in concert with 2-dimensional Fast Fourier Transform (2DFFT), we determined that the pitch angle of the redshift 2.011 galaxy GZ5001 (J2000 RA 189.14811 degrees, Dec 62.24002 degrees) is approximately (16.2 +/- 2.6) degrees. The redshift 2.3219 galaxy GS21 (J2000 RA 53.14863 degrees, Dec -27.95469 degrees), which is believed to be the most distant galaxy with visible spiral structure yet measured, has a pitch of approximately (-10.6 +/- 1.6) degrees ...


Quantum Physics And Relativity In Lovecraft's Fiction, Garrison McCammon 2017 Ursinus College

Quantum Physics And Relativity In Lovecraft's Fiction, Garrison Mccammon

English Summer Fellows

The early twentieth century brought about some of the best and most influential horror or weird tales ever written in the English speaking world. The most impressive and most lauded author of the group composed of such figures as Algernon Blackwood, M. R. James, Arthur Machen, Clark A. Smith, and Robert E. Howard was H. P. Lovecraft. Posthumously declared the literary successor to Edgar Allan Poe, Lovecraft’s fiction and tales of terror have cast such a huge shadow that every significant author in weird writing since his passing has claimed him as a literary heir. Lovecraft’s works were ...


Using Bolide Airwaves To Estimate Meteoroid Source Characteristics And Window Damage Potential, Nayeob Gi 2017 The University of Western Ontario

Using Bolide Airwaves To Estimate Meteoroid Source Characteristics And Window Damage Potential, Nayeob Gi

Electronic Thesis and Dissertation Repository

We examined the far-field infrasonic signals produced by 78 bolides simultaneously detected by U.S. government sensors to determine the mechanisms responsible for interstation spreads in infrasound signal period. These signal period spreads lead to large variances in source energy estimates. Our analysis suggests that while acoustic source height contributes to some extent to the variance in signal periods, the range from the source to the station and in particular station noise plays a more significant role.

By simulating the near-field weak shocks from a suite of well-observed energetic fireballs, we have empirically estimated how often fireball shocks produce overpressure ...


Milky Way Tomography With K And M Dwarf Stars: The Vertical Structure Of The Galactic Disk, Deborah Ferguson, Susan Gardner, Brian Yanny 2017 University of Kentucky

Milky Way Tomography With K And M Dwarf Stars: The Vertical Structure Of The Galactic Disk, Deborah Ferguson, Susan Gardner, Brian Yanny

Physics and Astronomy Faculty Publications

We use the number density distributions of K and M dwarf stars with vertical height from the Galactic disk, determined using observations from the Sloan Digital Sky Survey, to probe the structure of the Milky Way disk across the survey's footprint. Using photometric parallax as a distance estimator we analyze a sample of several million disk stars in matching footprints above and below the Galactic plane, and we determine the location and extent of vertical asymmetries in the number counts in a variety of thin- and thick-disk subsamples in regions of some 200 square degrees within 2 kpc in ...


Investigating Brown Dwarf Atmospheres: Gravity, Dust Content, Cloud Structure And Metallicity, Kendra Kellogg 2017 The University of Western Ontario

Investigating Brown Dwarf Atmospheres: Gravity, Dust Content, Cloud Structure And Metallicity, Kendra Kellogg

Electronic Thesis and Dissertation Repository

Brown dwarfs are the lowest mass products of star formation. Their low masses don't allow them to sustain, or sometimes even begin, the thermonuclear processes that provide stars with internal energy and the thermal pressure necessary to maintain hydrostatic equilibrium. Thus, their radii and effective temperatures decrease as they age, continually changing their spectral classification. However, it is now a well-known fact that the spectral appearance of ultra-cool dwarfs is governed by more than just temperature. Factors such as gravity, metallicity and cloud distribution play an important role in the structure and composition of ultra-cool dwarf atmospheres and ultimately ...


Photoelectric Magnitude Measurements Of The Lunar Eclipses On May 16, 2003 And Oct. 28, 2004, Richard W. Schmude Jr. 2017 Gordon State College

Photoelectric Magnitude Measurements Of The Lunar Eclipses On May 16, 2003 And Oct. 28, 2004, Richard W. Schmude Jr.

Georgia Journal of Science

The Moon's brightness dropped by 10.73 ± 0.07 and 10.61 ± 0.15 magnitudes during the total lunar eclipses on May 16, 2003 and Oct. 28, 2004 respectively. These magnitude drops are close to the corresponding value for the Jan., 2000 total lunar eclipse and indi­cate that not much change in the transparency of the atmosphere has occurred in the last 4 years.


Shakespeare, A Supernova, And A Little Green Man Walk Into A Mathematics Classroom, Sheila Kirstin Miller 2017 City University of New York

Shakespeare, A Supernova, And A Little Green Man Walk Into A Mathematics Classroom, Sheila Kirstin Miller

Journal of Humanistic Mathematics

Creativity amidst constraints is a hallmark of the STEM researcher. It is precisely what is required to see what has never been seen. It is also at the core of creative mathematics, more commonly called “research”. We in the 21st century tell ourselves that science and story are separate enterprises. One goal of this article is to tell parts of the human story—featuring Shakespeare, Tycho Brahe, visiting stars, Little Green Men, and modern astrophysics—that might erode belief in that duality and illustrate why dissolving the artificial barriers between talents within individuals is to the benefit of ourselves ...


Wideband Photometry Of Saturn In 2004-2005, Richard W. Schmude Jr. 2017 Gordon State College

Wideband Photometry Of Saturn In 2004-2005, Richard W. Schmude Jr.

Georgia Journal of Science

The writer made 60 photometric measurements of Saturn + rings between Nov. 5, 2004 and Jan. 21, 2005. The normalized magnitudes of Saturn for a ring tilt angle of 22° are B(1,0) = -8.55 ± 0.01, V(1,0) = -9.60 ± 0.01, B(1,0) = -10.27 ± 0.01, and I(1,0) = -10. 4 7 ± 0.01; the corresponding solar phase angle coefficients are cB = 0.027 ± 0.006, cV = 0.021 ± 0.005, cB = 0.020 ± 0.005, and cB = 0.022 ± 0.005. The 2005 opposition surge values (in magnitudes at ...


Digital Commons powered by bepress