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

Astrophysics and Astronomy Commons™

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

Astronomy

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 271 - 300 of 307

Full-Text Articles in Astrophysics and Astronomy

0937+2931_Opt_Lris, Adam J. Burgasser Sep 2003

0937+2931_Opt_Lris, Adam J. Burgasser

Publications and Research

No abstract provided.


Book Review: Observer's Guide To Stellar Evolution: The Birth, Life, And Death Of Stars, T. D. Oswalt Sep 2003

Book Review: Observer's Guide To Stellar Evolution: The Birth, Life, And Death Of Stars, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Observer's Guide to Stellar Evolution : the Birth, Life, and Death of Stars by Mike Inglis. Springer, 2003 236p, 1-85233-465-7 $44.95


Book Review: Strange Matters: Undiscovered Ideas At The Frontiers Of Space And Time, T. D. Oswalt Mar 2003

Book Review: Strange Matters: Undiscovered Ideas At The Frontiers Of Space And Time, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Strange Matters: Undiscovered Ideas at the Frontiers of Space and Time by Tom Siegfried. John Henry, 2002 307p, 0-309-08407-5 $24.95.


Book Review: Neptune: The Planet, Rings And Satellites, T. D. Oswalt Sep 2002

Book Review: Neptune: The Planet, Rings And Satellites, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Neptune : the Planet, Rings and Satellites by Ellis D. Miner and Randii R. Wessen Springer/Praxis, 2002 297p, 1-85233-216-6 $44.95


Book Review: Flash!: The Hunt For The Biggest Explosions In The Universe, T. D. Oswalt Jan 2002

Book Review: Flash!: The Hunt For The Biggest Explosions In The Universe, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of Flash! : the hunt for the biggest explosions in the universe by Govert Schilling. tr. by Naomi Greenberg-Slovin Cambridge, 2002 291p, 0-521-80053-6 $28.00


Book Review: The Observing Guide To The Messier Marathon: A Handbook And Atlas, T. D. Oswalt Jan 2002

Book Review: The Observing Guide To The Messier Marathon: A Handbook And Atlas, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Observing Guide to the Messier Marathon : a Handbook and Atlas by Don Machholz. Cambridge, 2002 157p, 0-521-80386-1 $25.00.


0920+3517_Nir_Spex, Maria Teresa Ruiz Mar 2001

0920+3517_Nir_Spex, Maria Teresa Ruiz

Publications and Research

No abstract provided.


A Desktop Universe For The Introductory Astronomy Laboratory, Laurence A. Marschall, Glenn A. Snyder, Paul Richard Cooper Dec 2000

A Desktop Universe For The Introductory Astronomy Laboratory, Laurence A. Marschall, Glenn A. Snyder, Paul Richard Cooper

Physics and Astronomy Faculty Publications

What is a well-intentioned astronomy instructor to do? There is no argument that experience with the real world is desirable in any astronomy course, especially the introductory classes that fulfill the science distribution requirements at many colleges and universities. Though it is a simple matter to take students out of doors, show them the motions of the Sun, Moon, and stars, and have them squint for a few seconds at Saturn's rings through a telescope, these activities represent only a small portion of the subject matter of modern astronomy. It is simply not possible, given the constraints of time, weather, …


Book Review: 3-D Atlas Of Stars And Galaxies, T. D. Oswalt Nov 2000

Book Review: 3-D Atlas Of Stars And Galaxies, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of 3-D Atlas of Stars and Galaxies by Richard Monkhouse and John Cox Springer, 2000. 95p, 1-85233-189-5 $42.00.


1237+6526_Opt_Lris, Adam J. Burgasser Jul 2000

1237+6526_Opt_Lris, Adam J. Burgasser

Publications and Research

No abstract provided.


Book Review: The Birth Of Time: How Astronomers Measured The Age Of The Universe, T. D. Oswalt Jan 2000

Book Review: The Birth Of Time: How Astronomers Measured The Age Of The Universe, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Birth of Time : How Astronomers Measured the Age of the Universe by John Gribbin. Yale, 2000 237p, 0-300-08346-7 $22.50.


Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner Jan 1996

Basic Astronomy Labs, Terry L. Smith, Michael D. Reynolds, Jay S. Huebner

Physics Faculty Research and Scholarship

Providing the tools and know-how to apply the principles of astronomy first-hand, these 43 laboratory exercises each contain an introduction that clearly shows budding astronomers why the particular topic of that lab is of interest and relevant to astronomy. About one-third of the exercises are devoted solely to observation, and no mathematics is required beyond simple high school algebra and trigonometry.Organizes exercises into six major topics—sky, optics and spectroscopy, celestial mechanics, solar system, stellar properties, and exploration and other topics—providing clear outlines of what is involved in the exercise, its purpose, and what procedures and apparatus are to be used. …


Chromospherically Active Stars. Xiii. Hd 30957: A Double Lined K Dwarf Binary, Francis C. Fekel, Virgiljus Dadonas, Julius Sperauskas, Todd R. Vaccaro, L. Ronald Patterson Nov 1994

Chromospherically Active Stars. Xiii. Hd 30957: A Double Lined K Dwarf Binary, Francis C. Fekel, Virgiljus Dadonas, Julius Sperauskas, Todd R. Vaccaro, L. Ronald Patterson

Information Systems and Engineering Management Research Publications

HD 30957 is a double-lined spectroscopic binary with a period of 44.395 days and a modest eccentricity of 0.09. The spectral types of the components are K2-3 V and K5 V. The measured v sin i for both components is less than or equal to 3 km/s and the orbital inclination is estimated to be 69 deg. The system is relatively nearby with a parallax of 0.025 sec or a distance of 40 pc. Space motions of the system indicate that it does not belong to any of the known moving groups. Absolute surface fluxes of the Ca II H …


Structural Characteristics And Stellar Composition Of Low Surface Brightness Disk Galaxies, Stacy S. Mcgaugh Feb 1994

Structural Characteristics And Stellar Composition Of Low Surface Brightness Disk Galaxies, Stacy S. Mcgaugh

Faculty Scholarship

We present UBVI surface photometry of a sample of low surface brightness (LSB) disk galaxies. LSB disk galaxies are fairly well described as exponential disks with no preferred value for either scale length, central surface brightness, or rotational velocity. Indeed, the distribution of scale lengths is indistinguishable from that of high surface brightness spirals, indicating that dynamically similar galaxies (e.g., those with comparable v2R) exist over a large range in surface density. These LSB galaxies are strikingly blue. The complete lack of correlation between central surface brightness and color rules out any fading scenario. Similarly, the oxygen abundances inferred from …


Chromospherically Active Stars. Xi. Giants With Compact Hot Companions And The Barium Star Scenario, Francis C. Fekel, Gregory W. Henry, Michael R. Busby, Joseph J. Eitter Dec 1993

Chromospherically Active Stars. Xi. Giants With Compact Hot Companions And The Barium Star Scenario, Francis C. Fekel, Gregory W. Henry, Michael R. Busby, Joseph J. Eitter

Information Systems and Engineering Management Research Publications

We have determined spectroscopic orbits for three chromsopherically active giants that have hot compact companions. They are HD 160538 (KO III + wd, P = 904 days), HD 165141 (G8 III + wd, P approximately 5200 days), and HD 185510 (KO III + sdB, P = 20.6619 days). By fitting an IUE spectrum with theoretical models, we find the white dwarf companion of HD 165141 has a temperature of about 35,000 K. Spectral types and rotational velocities have been determined for the three giants and distances have been estimated. These three systems and 39 Ceti are compared with the barium …


Extremely Active Long-Period Rs Cvn Binary Hd 12545, Bernard W. Bopp, Francis C. Fekel, Jason P. Aufdenberg, Robert C. Dempsey, Virgiljus Dadonas Dec 1993

Extremely Active Long-Period Rs Cvn Binary Hd 12545, Bernard W. Bopp, Francis C. Fekel, Jason P. Aufdenberg, Robert C. Dempsey, Virgiljus Dadonas

Information Systems and Engineering Management Research Publications

The active-chromosphere giant HD 12545 is noteworthy for its remarkable 1990 photmetric amplitude of 0.6 mag in V, which implies that nearly half the visible hemisphere of the star was covered by cool spots. We report the results of a spectroscopic study of HD 12545, showing it to be an active-chromosphere binary with an orbital period of 23.97 days. We establish the spectral type as KO III, and measure v sin i = 17 +/- 2 km/s. The various indicators of activity in the optical and ultraviolet suggest that HD 12545 is one of the most active RS CVn systems …


The Spectroscopic Orbit Of Gamma Geminorum And A Search For Its Secondary, Francis C. Fekel, Jocelyn Tomkin Sep 1993

The Spectroscopic Orbit Of Gamma Geminorum And A Search For Its Secondary, Francis C. Fekel, Jocelyn Tomkin

Information Systems and Engineering Management Research Publications

New spectroscopic observations of Gamma Geminorum, a bright, 'normal' A1 IV star have resulted in an improved spectroscopic orbit. The orbital period is 12.632 +/- 0.002 yr, the eccentricity is 0.893 +/-0.002, and the orbital parallax is 0.0291 +/-0.0024 arcsec, or a distance of 34 pc. We determine a v sin i of 8 +/-1 km/s for the A star, which confirms that it is a slow rotator. Near-infrared spectroscopic observations at 8806 A, obtained through the brief nodal passage, have resulted in the probable detection of the secondary. The masses are 2.8 and 1.07 solar mass and the Delta …


The Measurement Of Astronomical Parallaxes With Ccd Imaging Cameras On Small Telescopes, Stephen J. Ratcliff, Thomas J. Balonek, Laurence A. Marschall, David L. Dupuy, Carlton R. Pennypacker, Ritu Verma, Anastasia Alexov, Vivian Bonney Mar 1993

The Measurement Of Astronomical Parallaxes With Ccd Imaging Cameras On Small Telescopes, Stephen J. Ratcliff, Thomas J. Balonek, Laurence A. Marschall, David L. Dupuy, Carlton R. Pennypacker, Ritu Verma, Anastasia Alexov, Vivian Bonney

Physics and Astronomy Faculty Publications

Small telescopes equipped with charge-coupled device (CCD) imaging cameras are well suited to introductory laboratory exercises in positional astronomy (astrometry). An elegant example is the determination of the parallax of extraterrestrial objects, such as asteroids. For laboratory exercises suitable for introductory students, the astronomical hardware needs are relatively modest, and under the best circumstances, the analysis requires little more than arithmetic and a microcomputer with image display capabilities. Results from the first such coordinated parallax observations of asteroids ever made are presented. In addition, procedures for several related experiments, involving single-site observations and/or parallaxes of earth-orbiting artificial satellites, are outlined.


In The Astronomy Tradition At Augustana, Harry E. Nelson Jan 1992

In The Astronomy Tradition At Augustana, Harry E. Nelson

Augustana Historical Society Publications

Abstract: “In the Astronomy Tradition at Augustana was written as a response to a suggestion made by Dr. Conrad Bergendoff, president emeritus at Augustana College, Rock Island, Illinois. I had prepared a paper for the Contemporary Club of Davenport, Iowa which dealt with the program of the John Deere Planetarium on the campus and its contribution to the Quad-Cities community. Dr. Bergendoff felt that a more inclusive report was needed, and he convinced me that I should write the complete history of the astronomy department. His many creative suggestions have made the story most interesting and I am indebted …


The 11 Year History Of Starspots On V1149 Ori=Hd 37824, Douglas S. Hall, Francis C. Fekel, Gregory W. Henry, William S. Barksdale Nov 1991

The 11 Year History Of Starspots On V1149 Ori=Hd 37824, Douglas S. Hall, Francis C. Fekel, Gregory W. Henry, William S. Barksdale

Information Systems and Engineering Management Research Publications

All available radial-velocity measures, published and unpublished, yield an improved period and a new (assumed circular) solution. The period is 53.58 d +/- 0.02 d, and conjunction (K1 giant in front) was at 2 444 325.93 +/- 0.12 d. Eleven years of V-band photometry, published and unpublished, between 1978-1979 and 1989-1990 are analyzed. Eighteen data groups are fit with a two-spot light-curve-modeling technique. Six spots existing sometime during the 11 years are identified, and the 4-percent range of their rotation periods is used to estimate a differential rotation coefficient of k = 0.08 +/- 0.02. Observed lifetimes of those six …


Uv Observations Of The Cool Dbqa5 White Dwarf Lds 678a - Limits On The Atmospheric Composition, Pressure Shift, And Gravitational Redshift Derived From C I 2479, Terry D. Oswalt, Edward M. Sion, Gordon Hammond, Gerard Vauclair, James W. Liebert, Gary Wegner Jan 1991

Uv Observations Of The Cool Dbqa5 White Dwarf Lds 678a - Limits On The Atmospheric Composition, Pressure Shift, And Gravitational Redshift Derived From C I 2479, Terry D. Oswalt, Edward M. Sion, Gordon Hammond, Gerard Vauclair, James W. Liebert, Gary Wegner

Dartmouth Scholarship

A high-resolution ultraviolet spectrum of the helium-rich degenerate LDS 678A, obtained with the International Ultraviolet Explorer (IUE) satellite, is presented. LDS 678A is the coolest metallic line degenerate (DQ or DZ) yet observed with the IUE echelle. These observations provide a detailed line profile of the strong C I 2479 absorption line and equivalent width W2479 = 2.35 + or - 0.06 A from which theoretical profile fits yield a carbon abundance of log C/He = (-6.7 + or- 0.2). The presence of carbon in a He-rich atmosphere lends credence to the notion that LDS 678A is a transitional case …


Stellar Populations In Shell Galaxies, Stacy S. Mcgaugh Oct 1990

Stellar Populations In Shell Galaxies, Stacy S. Mcgaugh

Faculty Scholarship

UBV surface photometry of the shell galaxies Arp 230, NGC 7010, and Arp 223 is presented. We find all to be the result of mergers. In Arp 230, the merger of two spirals reduced a burst of star formation which has declined in strength since the collision. The remnant seems likely to become elliptical. NGC 7010 has very red shells, perhaps redder than the galaxy itself. Evolution of the stellar content of these shells may be important. Arp 223 has shell colors which are slightly bluer than thee main body of the galaxy, consistent with an origin in an Sb. …


Chromospherically Active Stars. Vi. Hd 136901 = Uv Crb: A Massive Ellipsoidal K Giant Single-Lined Spectroscopic Binary, Francis C. Fekel, J. Davy Kirkpatrick, Xinxing Yang, Klaus G. Strassmeier Jan 1989

Chromospherically Active Stars. Vi. Hd 136901 = Uv Crb: A Massive Ellipsoidal K Giant Single-Lined Spectroscopic Binary, Francis C. Fekel, J. Davy Kirkpatrick, Xinxing Yang, Klaus G. Strassmeier

Information Systems and Engineering Management Research Publications

The variable star HD 136901 = UV CrB is a chromospherically active K2 III single-lined spectroscopic binary with an orbital period of 18.665 days. It has modest-strength Ca H and K emission and UV features, while H-alpha is a strong absorption feature containing little or no emission. The inclination of the system is 53 + or - 12 deg. The v sin i of the primary is 42 + or - 2 km/s, resulting in a minimum radius of 15.5 + or - 0.8 solar. When compared with the Roche lobe radius, this results in a mass ratio of 2.90 …


A Working Catalogue Of Herbig Haro Objects, Ted Von Hippel, S.J. Bell Burnell, P.M. Williams Sep 1988

A Working Catalogue Of Herbig Haro Objects, Ted Von Hippel, S.J. Bell Burnell, P.M. Williams

Publications

We present a catalogue of 184 Herbig Haro objects from a literature search complete to 1987.5. It is intended to update the 1974 catalogue of Herbig. The catalogue contains accurate co-ordinates, proper motions, radial velocities and spectral information for these objects. A cross-reference to the two best finding charts is included. A grouping of Herbig Haro objects into is also listed.


West Mountain Observatory: Planning And Construction Pictorial History, Gene Libutti Jan 1982

West Mountain Observatory: Planning And Construction Pictorial History, Gene Libutti

BYU West Mountain Observatory Project

No abstract provided.


Observations And Analysis Of The Aquarii Jet, Menas Kafatos, Andrew G. Michalitsianos Jan 1982

Observations And Analysis Of The Aquarii Jet, Menas Kafatos, Andrew G. Michalitsianos

Mathematics, Physics, and Computer Science Faculty Books and Book Chapters

Ultraviolet, optical and radio observations of the symbiotic star R Aquarii are discussed in the light of the discovery of a bright radio and optical jet from this star. The star is probably a binary with a period of 44 years. The VLA maps of the jet reveal a protruding structure extending-10 arc sec from the central radio source with a position angle virtually identical to that of the optical jet observed at Lick. We interpret the observations of R Aqr as indicating the existence of an accretion disk around an unseen companion. The hot subdwarf has effective temperature ,(65,000 …


West Of Utah Lake: Building Nears Finish, Marc Enggas Feb 1981

West Of Utah Lake: Building Nears Finish, Marc Enggas

BYU West Mountain Observatory Project

No abstract provided.


Program For New Observatory Facility For Brigham Young University, Provo, Utah, Byu Department Of Physics And Astronomy Nov 1979

Program For New Observatory Facility For Brigham Young University, Provo, Utah, Byu Department Of Physics And Astronomy

BYU West Mountain Observatory Project

No abstract provided.


Astronomy And The Bible: Joshua's Long Day, Joel W. Block Nov 1977

Astronomy And The Bible: Joshua's Long Day, Joel W. Block

Physics Faculty Publications

The Bible has served as a multipurpose text for thousands of years. However, the Bible has been ignored in the area of astronomy. Several teaching points can be demonstrated using the Bible stories and modern astronomical principles.


4. Kepler, Robert L. Bloom, Basil L. Crapster, Harold A. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart Jan 1958

4. Kepler, Robert L. Bloom, Basil L. Crapster, Harold A. Dunkelberger, Charles H. Glatfelter, Richard T. Mara, Norman E. Richardson, W. Richard Schubart

Section VIII: The Development of Modern Science

Tycho Brahe (1546-1601), a Dane, spent nearly his entire life making careful measurements of the positions of the stars and planets. Most of his work was done at Copenhagen under the patronage of the Danish king. He developed and refined astronomical instruments to an accuracy that was far superior to anything previously done. In his late years at Prague, he started on the reduction to order of the systematic observations that he had made over a period of decades. In 1600 a young German mathematician and astronomer, Johannes Kepler (1571-1630), visited Tycho and then stayed to help in the mammoth …