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

Astrophysics and Astronomy Commons™

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

Embry-Riddle Aeronautical University

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 421 - 450 of 494

Full-Text Articles in Astrophysics and Astronomy

Lorentz-Violating Electromagnetostatics, Quentin G. Bailey Aug 2004

Lorentz-Violating Electromagnetostatics, Quentin G. Bailey

Publications

In this talk, the stationary limit of Lorentz-violating electrodynamics is discussed. As illustrated by some simple examples, the general solution includes unconventional mixing of electrostatic and magnetostatic effects. I discuss a high-sensitivity null-type measurement, exploiting Lorentz-violating electromagnetostatic effects, that could improve existing limits on parity-odd coefficients for Lorentz violation in the photon sector.

Go to article

Proper Motion Objects In The Hubble Deep Field, M. Kilic, Ted Von Hippel, Et Al. Jul 2004

Proper Motion Objects In The Hubble Deep Field, M. Kilic, Ted Von Hippel, Et Al.

Publications

Using the deepest and finest resolution images of the universe acquired with the Hubble Space Telescope and a similar image taken 7 yr later for the Great Observatories Origins Deep Survey, we have derived proper motions for the point sources in the Hubble Deep Field–North. Two faint blue objects, HDF 2234 and HDF 3072, are found to display significant proper motion, 10:0 ± 2:5 and 15:5 ± 3:8 mas yr¯1. Photometric distances and tangential velocities for these stars are consistent with disk white dwarfs located at ~500 pc. The faint blue objects analyzed by Ibata et al. and Mendez & …

Go to article

Cluster Observations Of Magnetic Field Fluctuations In The High-Altitude Cusp, K. Nykyri, P. J. Cargill, E. Lucek, T. Horbury, B. Lavraud, A. Balogh, M. W. Dunlop, Et Al. Jul 2004

Cluster Observations Of Magnetic Field Fluctuations In The High-Altitude Cusp, K. Nykyri, P. J. Cargill, E. Lucek, T. Horbury, B. Lavraud, A. Balogh, M. W. Dunlop, Et Al.

Publications

High-resolution (22 vector/s) magnetic field data from Cluster FGM instrument are presented for the highaltitude cusp crossing on 17 March 2001. Despite the quiet solar wind conditions, the cusp was filled with magnetic field turbulence for much of the crossing. Large-scale fluctuations show some correlation between spacecraft but the higher frequency fluctuations show no correlation, indicating that the length scales of these waves are smaller than the spacecraft separation (500 km). In many intervals, there are clear peaks in the wave power around the ion cyclotron frequency (~1 Hz), and there is some evidence for waves at the first harmonic …

Go to article

Thirty-Five New Pulsating Da White Dwarf Stars, Anjum S. Mukadam, Ted Von Hippel, Et Al. Jun 2004

Thirty-Five New Pulsating Da White Dwarf Stars, Anjum S. Mukadam, Ted Von Hippel, Et Al.

Publications

We present 35 new pulsating DA (hydrogen atmosphere) white dwarf stars discovered from the Sloan Digital Sky Survey (SDSS) and the Hamburg Quasar Survey (HQS). We have acquired high-speed time series photometry of preselected DA white dwarfs with a prime focus CCD photometer on the 2.1 m telescope at McDonald Observatory over 15 months. We selected these stars on the basis of prior photometric and spectroscopic observations by the SDSS and HQS. For the homogeneous SDSS sample, we achieve a success rate of 80% for finding new variables at a detection threshold of 0.1%-0.3%. With 35 newly discovered DA variable …

Go to article

Book Review: The Edge Of Infinity: Supermassive Black Holes In The Universe, T. D. Oswalt Jun 2004

Book Review: The Edge Of Infinity: Supermassive Black Holes In The Universe, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Edge of Infinity : Supermassive Black Holes in the Universe by Fulvio Melia. Cambridge, 2003 148p, 0-521-81405-7 $30.00.

Go to article

Re-Defining The Empirical Zz Ceti Instability Strip, Anjum S. Mukadam, Ted Von Hippel, D. E. Winget,, M. H. Montgomery May 2004

Re-Defining The Empirical Zz Ceti Instability Strip, Anjum S. Mukadam, Ted Von Hippel, D. E. Winget,, M. H. Montgomery

Publications

We use the new ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to re-define the empirical ZZ Ceti instability strip. This is the first time since the discovery of white dwarf variables in 1968 that we have a homogeneous set of spectra acquired using the same instrument on the same telescope, and with con- sistent data reductions, for a statistically significant sample of ZZ Ceti stars. The homogeneity of the spectra reduces the scatter in the spectroscopic temperatures and we find a narrow instability strip of width ∼ …

Go to article

Data-Model Comparison Search Analysis Of Coincident Pbo Balmer Α, Eurd Lyman Β Geocoronal Measurements From March 2000, J. Bishop, E. J. Mierkiewicz, F. L. Roesler, J. F. Gómez, C. Morales May 2004

Data-Model Comparison Search Analysis Of Coincident Pbo Balmer Α, Eurd Lyman Β Geocoronal Measurements From March 2000, J. Bishop, E. J. Mierkiewicz, F. L. Roesler, J. F. Gómez, C. Morales

Publications

Recent Lyman series and Balmer series airglow measurements provide a fresh opportunity to investigate the density distribution and variability of atomic hydrogen in the upper atmosphere. Dedicated nightside Balmer α Fabry-Perot spectrometer measurements at the Pine Bluff Observatory (PBO), University of Wisconsin-Madison, have been acquired since late 1999 taking advantage of several technological advances. Extreme ultraviolet spectral radiance measurements by the Espectrógrafo Ultravioleta extremo para la Radiación Difusa (EURD) instrument on the Spanish MINISAT-1 satellite from October 1997 to December 2001 provide extensive sets of geocoronal Lyman β, Lyman γ and He 584 Å emission intensities. In this paper, coincident …

Go to article

Spectroscopic And Photometric Analysis Of Hs 1136+6646: A Hot Young Dao+K7 V Post-Common-Envelope, Pre-Cataclysmic Variable Binary, D. K. Sing, Terry D. Oswalt, J. B. Holberg, M. R. Burleigh, S. A. Good, Et Al. May 2004

Spectroscopic And Photometric Analysis Of Hs 1136+6646: A Hot Young Dao+K7 V Post-Common-Envelope, Pre-Cataclysmic Variable Binary, D. K. Sing, Terry D. Oswalt, J. B. Holberg, M. R. Burleigh, S. A. Good, Et Al.

Publications

Extensive photometric and spectroscopic observations have been obtained for HS 1136+6646. The observations reveal a newly formed post–common-envelope binary system containing a hot ~DAO.5 primary and a highly irradiated secondary. HS 1136+6646 is the most extreme example yet of a class of short-period hot H-rich white dwarfs with K–M companion systems such as V471 Tau and Feige 24. HS 1136+6646 is a double-line spectroscopic binary showing emission lines of H i, He ii, C ii, Ca ii, and Mg ii, due in part to irradiation of the K7 V secondary by the hot white dwarf. Echelle spectra reveal the hydrogen …

Go to article

Cluster Encounters With The High Altitude Cusp: Boundary Structure And Magnetic Field Depletions, P. J. Cargill, M. W. Dunlop, B. Lavraud, R. C. Elphic, D. L. Holland, K. Nykyri, A. Balogh, I. Dandouras Apr 2004

Cluster Encounters With The High Altitude Cusp: Boundary Structure And Magnetic Field Depletions, P. J. Cargill, M. W. Dunlop, B. Lavraud, R. C. Elphic, D. L. Holland, K. Nykyri, A. Balogh, I. Dandouras

Publications

Data from the four spacecraft Cluster mission during a high altitude cusp crossing on 13 February 2001 are presented. The spacecraft configuration has one leading spacecraft, with the three trailing spacecraft lying in a plane that corresponds roughly to the nominal magnetopause surface. The typical spacecraft separation is approximately 600 km. The encounter occurs under conditions of strong and steady southward Interplanetary Magnetic Field (IMF). The cusp is identified as a seven-minute long depression in the magnetic field, associated with ion heating and a high abundance of He+. Cusp entry involves passage through a magnetopause boundary that has undergone very …

Go to article

Observations Of Solar Cyclical Variations In Geocoronal Hα Column Emission Intensities, S. M. Nossal, F. L. Roesler, E. J. Mierkiewicz, R. J. Reynolds Mar 2004

Observations Of Solar Cyclical Variations In Geocoronal Hα Column Emission Intensities, S. M. Nossal, F. L. Roesler, E. J. Mierkiewicz, R. J. Reynolds

Physical Sciences - Daytona Beach

Observations of thermospheric + exospheric Hα column emissions by the Wisconsin Hα Mapper (WHAM) Fabry-Perot (Kitt Peak, Arizona) over the 1997–2001 rise in solar cycle 23 show a statistically significant solar cyclical variation. The higher signal-to-noise WHAM observations corroborate suggestions of a solar cycle trend in the Hα emissions seen in Wisconsin observations over solar cycle 22. Here we compare WHAM 1997 and 2000–2001 winter solstice geocoronal Hα observations toward regions of the sky with low galactic emission. The observed variation in geocoronal hydrogen column emission intensities over the solar cycle is small compared with variations in hydrogen exobase densities. …

Go to article

Influence Of The Hall Term On Kh Instability And Reconnection Inside Kh Vortices, K. Nykyri, A. Otto Feb 2004

Influence Of The Hall Term On Kh Instability And Reconnection Inside Kh Vortices, K. Nykyri, A. Otto

Publications

The Kelvin-Helmholtz instability (KHI) in its nonlinear stage can develop small-scale filamentary field and current structures at the flank boundaries of the magnetosphere. It has been shown previously with MHD simulations that magnetic reconnection can occur inside these narrow current layers, resulting in plasma transport from the solar wind into the magnetosphere. During periods of northward IMF, this transport is sufficient to generate a cold, dense plasma sheet on time scales consistent with satellite observations. However, when the length scales of these narrow current layers approach the ion inertia scale, the MHD approximation is not valid anymore and the Hall …

Go to article

Book Review: The Big Bang: A View From The 21st Century, T. D. Oswalt Feb 2004

Book Review: The Big Bang: A View From The 21st Century, T. D. Oswalt

Publications

This document is Dr. Oswalt’s review of The Big Bang : a View from the 21st Century by David M. Harland. Springer/Praxis, 2003 262p, 1-85233-713-3 $39.95.

Go to article

Ion Cyclotron Waves In The High Altitude Cusp: Cluster Observations At Varying Spacecraft Separations, K. Nykyri, P. J. Cargill, E. A. Lucek, T. S. Horbury, A. Balogh, B. Lavraud, I. Dandouras, H. Reme Dec 2003

Ion Cyclotron Waves In The High Altitude Cusp: Cluster Observations At Varying Spacecraft Separations, K. Nykyri, P. J. Cargill, E. A. Lucek, T. S. Horbury, A. Balogh, B. Lavraud, I. Dandouras, H. Reme

Publications

We have analysed high-resolution Cluster magnetic field data during three high-altitude cusp crossings in 2001 and 2002. The Cluster separations for these crossings varied between 100 and 600 km and therefore provided an unique opportunity to study wave properties at different length scales. In the cusp Cluster sees frequent intervals of magnetic field fluctuations with clear peaks in power close to the local ion cyclotron frequency, and both left- and right-handed polarisations. At large separations the power seen at different spacecraft can differ by orders of magnitude. For smaller separations, the power seen at the four spacecraft agrees better but …

Go to article

Using Optical And Near-Infrared Photometry To Test Macho Lens Candidates, Ted Von Hippel, Et Al. Oct 2003

Using Optical And Near-Infrared Photometry To Test Macho Lens Candidates, Ted Von Hippel, Et Al.

Publications

We obtained new VLT/ISAAC H-band observations for five MACHO LMC source stars and adjacent LMC field regions. After combining our near-IR photometry with Hubble Space Telescope/PC BVRI optical photometry, we compared the MACHO objects to the adjacent field stars in a variety of color-magnitude and color-color diagrams. These diagnostic diagrams were chosen to be sensitive to our hypothesis that at least some of the MACHO lenses were foreground Galactic disk or thick-disk M dwarfs. For the five lensed objects we studied, our hypothesis could be ruled out for main-sequence lens masses ≥0.1 M☉ for distances out to …

Go to article

Constraining The Evolution Of Zz Ceti, Anjum S. Mukadam, S. O. Kepler, D. E. Nather, M. Kilic, F. Mullally, T. Von Hippel, S. J. Kleinman, A. Nitta, J. A. Guzik, P. A. Bradley, J. Matthews, K. Sekiguchi, D. J. Sullivan, T. Sullivan, R. R. Shobbrook, P. Birch, X. J. Jiang, D. W. Xu, S. Joshi, B. N. Ashoka, P. Ibbetson, E. Leibowitz, E. O. Ofek, E. G. Meištas, R. Janulis, R. D. Ališauskas, R. Kalytis, G. Handler, D. Kilkenny, D. O'Donoghue, D. W. Kurtz, M. Müller, P. Moskalik, W. Ogloza, S. Zola, J. Krzesiński, F. Johnannessen, J. M. Gonzalez-Perez, J. E. Solheim, R. Silvotti, S. Bernabei, G. Vauclair, N. Dolez, J. N. Fu, M. Chevreton, M. Manteiga, O. Suárez, A. Ulla, M. S. Cunha, T. S. Metcalfe, A. Kanaan, L. Fraga, A. F. M. Costa, O. Giovannini, G. Fontaine, P. Bergeron, M. S. O'Brien, D. Sanwal, M. A. Wood, T. J. Ahrens, N. Silvestri, E. W. Klumpe, S. D. Kawaler, R. Riddle, M. D. Reed, T. K. Watson Sep 2003

Constraining The Evolution Of Zz Ceti, Anjum S. Mukadam, S. O. Kepler, D. E. Nather, M. Kilic, F. Mullally, T. Von Hippel, S. J. Kleinman, A. Nitta, J. A. Guzik, P. A. Bradley, J. Matthews, K. Sekiguchi, D. J. Sullivan, T. Sullivan, R. R. Shobbrook, P. Birch, X. J. Jiang, D. W. Xu, S. Joshi, B. N. Ashoka, P. Ibbetson, E. Leibowitz, E. O. Ofek, E. G. Meištas, R. Janulis, R. D. Ališauskas, R. Kalytis, G. Handler, D. Kilkenny, D. O'Donoghue, D. W. Kurtz, M. Müller, P. Moskalik, W. Ogloza, S. Zola, J. Krzesiński, F. Johnannessen, J. M. Gonzalez-Perez, J. E. Solheim, R. Silvotti, S. Bernabei, G. Vauclair, N. Dolez, J. N. Fu, M. Chevreton, M. Manteiga, O. Suárez, A. Ulla, M. S. Cunha, T. S. Metcalfe, A. Kanaan, L. Fraga, A. F. M. Costa, O. Giovannini, G. Fontaine, P. Bergeron, M. S. O'Brien, D. Sanwal, M. A. Wood, T. J. Ahrens, N. Silvestri, E. W. Klumpe, S. D. Kawaler, R. Riddle, M. D. Reed, T. K. Watson

Publications

We report our analysis of the stability of pulsation periods in the DAV star (pulsating hydrogen atmosphere white dwarf) ZZ Ceti, also called R548. On the basis of observations that span 31 years, we conclude that the period 213.13 s observed in ZZ Ceti drifts at a rate dP/dt ≤ (5:5 ± 1:9) x 10-15 s s-1, after correcting for proper motion. Our results are consistent with previous Ṗ values for this mode and an improvement over them because of the larger time base. The characteristic stability timescale implied for the pulsation period is …

Go to article

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

Go to article

Multisite Observations Of The Pms Δ Delta Scuti Star V351 Ori, V. Ripepi, Terry D. Oswalt, M. Marconi, S. Bernabei, Et Al. Jun 2003

Multisite Observations Of The Pms Δ Delta Scuti Star V351 Ori, V. Ripepi, Terry D. Oswalt, M. Marconi, S. Bernabei, Et Al.

Publications

We present the results of multisite observations spanning two years on the pre–main-sequence (PMS) star V351 Ori. A total of around 180 hours of observations over 29 nights have been collected, allowing us to measure five different periodicities, most likely related to the Scuti variability of V351 Ori. Comparison with the predictions of linear nonadiabatic radial pulsation models put stringent constraints on the stellar parameters and indicate that the distance to V351 Ori is intermediate between the lower limit measured by Hipparcos (210 pc) and that of the Orion Nebula (450 pc). However, radial pulsation models are unable to reproduce …

Go to article

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.

Go to article

Measurement Of The Stochasticity Of Low-Latitude Geomagnetic Temporal Variations, Mark Anthony Reynolds, James A. Wanliss Jan 2003

Measurement Of The Stochasticity Of Low-Latitude Geomagnetic Temporal Variations, Mark Anthony Reynolds, James A. Wanliss

Publications

Ground magnetometer measurements of total magnetic field strength from 6 stations at low latitudes were analyzed using power spectrum and Hurst range scaling techniques. The Hurst exponents for most of these time-series were near 0.5, which indicates stochasticity, with the highest latitude stations exhibiting some persistence with Hurst exponents greater than 0.6. Although no definite correlations are evident, the relative increase of the Hurst exponent with latitude suggests the possibility that the underlying dynamics of the magnetosphere change with latitude. This result may help quantify the dynamics of the inner magnetosphere itself without the direct presence of the solar wind …

Go to article

Intergalactic Globular Clusters, Michael J. West, Ted Von Hippel, Patrick Cote, Henry C. Ferguson, Michael D. Gregg, Andres Jordan, Ronald O. Marzke, Nial R. Tanvir Jan 2003

Intergalactic Globular Clusters, Michael J. West, Ted Von Hippel, Patrick Cote, Henry C. Ferguson, Michael D. Gregg, Andres Jordan, Ronald O. Marzke, Nial R. Tanvir

Publications

We confirm and extend our previous detection of a popula- tion of intergalactic globular clusters in Abell 1185, and report the first discovery of an intergalactic globular cluster in the nearby Virgo cluster of galaxies. The numbers, colors and luminosities of these objects can place constraints on their origin, which in turn may yield new insights to the evolution of galaxies in dense environments.

Go to article

Production, Outflow, Velocity, And Radial Distribution Of H2o And Oh In The Coma Of Comet C/1995 O1 (Hale-Bopp) From Wide-Field Imaging Of Oh, Walter M. Harris, Frank Scherb, Edwin Mierkiewicz, Ronald Oliversen, Jeffrey Morgenthaler Oct 2002

Production, Outflow, Velocity, And Radial Distribution Of H2o And Oh In The Coma Of Comet C/1995 O1 (Hale-Bopp) From Wide-Field Imaging Of Oh, Walter M. Harris, Frank Scherb, Edwin Mierkiewicz, Ronald Oliversen, Jeffrey Morgenthaler

Physical Sciences - Daytona Beach

Observations of OH are a useful proxy of the water production rate (Q H2O) and outflow velocity (VH2O) in comets. From wide-field images taken on 1997 March 28 and April 8 that capture the entire scale length of the OH coma of comet C/1995 O1 (Hale-Bopp), we obtain Q OH from the model-independent method of aperture summation and Q H2O from the OH photochemical branching ratio, BROH. Using an adaptive ring summation algorithm, we extract the radial brightness distribution of OH 0-0 band emission out to cometocentric distances of up to 10 to the sixth power km, both as azimuthal …

Go to article

Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon Sep 2002

Search For Oxygen In Cool Dq White Dwarf Atmospheres, M. Kilic, Ted Von Hippel, D. E. Winget, D. F. Lester, D. Saumon

Publications

The existence of carbon in cool He white dwarf (WD) atmospheres has been known for a relatively long time[5]. The presence of carbon in these atmospheres is explained by convective dredge up of interior carbon [6]. Pelletier et al. (1986) presented the first detailed calculations of this process and showed that carbon diffuses upwards from the core into the base of the He-rich envelope where it can be dredged up by a surface convection zone. As the temperature of the star decreases, more carbon diffuses upward, and the base of convection zone moves deeper into the star, further enriching the …

Go to article

Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver Sep 2002

Identification Of Cool White Dwarfs In The Noao Deep Wide-Field Survey, M. Kilic, Don E. Winget, T. Von Hippel, C.F. Claver

Publications

The chronology of star formation is recorded in the white dwarf luminosity function (WDLF). White dwarf (WD) structure implies a relatively simple connection between WD luminosity and age. First attempts to exploit WDs as chronometers [3,4,6] showed that the WDLF was a map of the history of star formation in the disk, and a significant shortfall of low-luminosity degenerates–the inevitable consequence of the finite age of the disk. The shortfall near log(L/L⊙)≈−4.5 implies a disk age of 6.5–9.5 Gyr [2]. The WDLF from wide common proper motion binaries [5] does not show the shortfall seen by Liebert et al. (1988). …

Go to article

Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis Sep 2002

Wiyn Open Cluster Study. Xi. Wiyn 3.5 Meter Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BVI observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5 m telescope under excellent seeing conditions. These observations probe to V > 26 and display the lower main sequence in BV and VI CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the location …

Go to article

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

Go to article

Automated Stellar Spectral Classification And Parameterization For The Masses, Ted Von Hippel, Carlos Allende Prieto, Chris Sneden Aug 2002

Automated Stellar Spectral Classification And Parameterization For The Masses, Ted Von Hippel, Carlos Allende Prieto, Chris Sneden

Publications

Stellar spectroscopic classification has been successfully automated by a number of groups. Automated classification and parameterization work best when applied to a homogeneous data set, and thus these techniques primarily have been developed for and applied to large surveys. While most ongoing large spectroscopic surveys target extragalactic objects, many stellar spectra have been and will be obtained. We briefly summarize past work on automated classification and parameterization, with emphasis on the work done in our group. Accurate automated classification in the spectral type domain and parameterization in the temperature domain have been relatively easy. Automated parameterization in the metallicity domain, …

Go to article

Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel Aug 2002

Metal Abundances And Kinematics Of Bright Metal-Poor Giants Selected From The Lse Survey: Implications For The Metal-Weak Thick Disk, Timothy C. Beers, John S. Drilling, Silvia Rossi, Masashi Chiba, Jaehyon Rhee, Birgit Fṻhrmeister, John E. Norris, Ted Von Hippel

Publications

We report medium-resolution (1–2A ˚ ) spectroscopy and broadband (UBV) photometry for a sample of 39 bright stars (the majority of which are likely to be giants) selected as metal-deficient candidates from an objective-prism survey concentrating on Galactic latitudes below |b| = 30, the Luminous Stars Extension (LSE) survey of Drilling & Bergeron. Although the primary purpose of the LSE survey was to select OB stars (hence the concentration on low latitudes), the small number of bright metal-deficient giant candidates noted during this survey provide interesting information on the metal-weak thick disk (MWTD) population. Metal abundance estimates are obtained from …

Go to article

Wiyn Open Cluster Study Xi: Wiyn1 3.5m Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis Jan 2002

Wiyn Open Cluster Study Xi: Wiyn1 3.5m Deep Photometry Of M35 (Ngc 2168), Ted Von Hippel, Aaron Steinhauer, Ata Sarajedini, Constantine P. Deliyannis

Publications

We present deep BV I observations of the core of M35 and a nearby comparison field obtained at the WIYN 3.5m telescope under excellent seeing conditions. These observations probe to V > 26, and display the lower main sequence in BV and V I CMDs down to V = 23.3 and 24.6, respectively. At these faint magnitudes the background Galactic field stars are far more numerous than the cluster stars, yet by using a smoothing technique and CMD density distribution subtraction we are able to recover the cluster fiducial main sequence and luminosity function to V = 24.6. We find the …

Go to article

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

Go to article

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.

Go to article

First Prev Next Last