The White Dwarfs within 20 Parsecs of the Sun: Kinematics and Statistics (2009)
Sion, Edward M., Holberg, Jay B., Oswalt, Terry D., McCook, George P., Wasatonic, Richard
We present the kinematical properties, distribution of spectroscopic subtypes, stellar population subcomponents of the white dwarfs within 20 pc of the sun. We find no convincing evidence of halo...
Zellem, Robert, Hollon, Nicholas, Ballouz, Ronald-Louis, Sion, Edward M., Godon, Patrick, Gänsicke, Boris T., ...
We obtained Hubble STIS spectra of three nova-like variables: V751 Cygni, V380 Oph, and - the only confirmed nova-like variable known to be below the period gap - BK Lyn. In all three systems, the...
On The Accretion Rates of SW Sextantis Nova-Like Variables (2009)
Ballouz, Ronald-Louis, Sion, Edward M.
We present accretion rates for selected samples of nova-like variables having IUE archival spectra and distances uniformly determined using an infrared method by Knigge (2006). A comparison with...
V3885 Sagittarius: a Comparison with a Range of Standard Model Accretion Disks (2009)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula, Barrett, Paul E.
A $\widetilde{\chi}^2$ analysis of standard model accretion disk synthetic spectrum fits to combined $FUSE$ and STIS spectra of V3885 Sagittarius, on an absolute flux basis, selects a model that...
Modeling UX Ursae Majoris: An abundance of challenges (2008)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula
We present a system model for optical and far UV spectra of the nova-like variable UX UMa involving a white dwarf, secondary star, gas stream, hot spot and accretion disk using our code BINSYN and...
Report IAU Comm. 42, Close Binary Stars (2008)
Rucinski, Slavek M., Ribas, Ignasi, Scarfe, Colin D., Torres, Guillermo, Rucinski, Slavek M., Sion, Edward M., ...
Brief summaries are given about (1) close binary research from the perspective of the Bibliography of Close Binaries, (2) low-mass binaries and model discrepancies, (3) W UMa-type binaries, (4)...
Hamilton, Ryan T., Sion, Edward M.
The prototype nova-like variable VY Sculptoris was observed by the IUE during four different optical brightness states of the system. The FUV flux level from the highest state to the lowest state...
Synthetic Spectrum Constraints on a Model of the Cataclysmic Variable QU Carinae (2008)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula, Barrett, Paul E.
Neither standard model SEDs nor truncated standard model SEDs fit observed spectra of QU Carinae with acceptable accuracy over the range 900\AA to 3000\AA. Non-standard model SEDs fit the observation...
Martin A. Barstow, Ivan Hubeny, Thierry Lanz, Edward M. Sion, Jay B. Holberg
V opacity and places limits on the abundance of He which may be present. 1. Introduction - the view from EUV surveys Among the most significant problems in the study of hot white dwarf evolution has...
Simulations of the Boundary Layer Between a White Dwarf and its Accretion Disk (2007)
Balsara, Dinshaw S., Fisker, Jacob Lund, Godon, Patrick, Sion, Edward M.
Using a 2.5D time-dependent axisymmetric numerical code we recently developed, we solve the full compressible Navier-Stokes equations (including an alpha-viscosity prescription) to determine the...
An International Ultraviolet Explorer Archival Study of Dwarf Novae in Outburst (2007)
Hamilton, Ryan T., Urban, Joel A., Sion, Edward M., Riedel, Adric R., Voyer, Elysse N., Marcy, John T., ...
We present a synthetic spectral analysis of nearly the entire far ultraviolet International Ultraviolet Explorer (IUE) archive of spectra of dwarf novae in or near outburst. The study includes 46...
FUSE Observations of the Dwarf Novae UU Aql, BV Cen, and CH UMa in Quiescence (2007)
Sion, Edward M., Godon, Patrick, Cheng, Fuhua, Szkody, Paula
We report on FUSE spectra of three U Gem-type, long period, dwarf novae, UU Aql, BV Cen and CH UMa taken during their quiescence intervals. We discuss the line identifications in their spectra and...
Hubble Space Telescope Far Ultraviolet Spectroscopy of the Dwarf Nova VW Hyi in Superoutburst (2007)
Merritt, Jason, Night, Christopher, Sion, Edward M.
We obtained three consecutive HST spectroscopic observations of a single superoutburst of the dwarf nova VW Hydri. The spectra cover the beginning, middle, and end of the superoutburst. All of the...
MV Lyrae in Low, Intermediate, and High States (2006)
Linnell, Albert P., Szkody, Paula, Gansicke, Boris, Long, Knox S., Sion, Edward M., Hoard, D. W., ...
We use analysis results from a low state of the VY Sculptoris system MV Lyrae, considered in an earlier paper (Hoard et al., 2004, ApJ, 604, 346), to study archival IUE spectra taken during an...
A Synthetic Spectrum and Light Curve Analysis of the Cataclysmic Variable IX Velorum (2006)
Linnell, Albert P., Godon, Patrick, Hubeny, Ivan, Sion, Edward M., Szkody, Paula
Spectrum synthesis analysis of FUSE and STIS spectra of the cataclysmic variable IX Velorum successfully produces a system model. Light synthesis analysis of K band photometry shows that the...
Szkody, Paula, Mukadam, Anjum, Gaensicke, Boris T., Woudt, Patrick A., Solheim, Jan-Erik, Nitta, Atsuko, ...
Ultraviolet observations using the Solar Blind Channel on the Hubble Space Telescope provide light curves and low resolution spectra of three pulsating white dwarfs in the cataclysmic variables...
The Dwarf Novae During Quiescence (2006)
Urban, Joel A., Sion, Edward M.
We present a synthetic spectral analysis of nearly the entire FUV IUE archive of spectra of DNe in or near quiescence. We have examined all of the systems for which S/N permitted an analysis. The...
The hot white dwarf in the cataclysmic variable MV Lyrae (2005)
Hoard, D. W., Linnell, A. P., Szkody, Paula, Fried, Robert E., Sion, Edward M., Hubeny, Ivan, ...
We have obtained the first far-ultraviolet spectrum of the novalike cataclysmic variable MV Lyrae using the Far Ultraviolet Spectroscopic Explorer. We also obtained contemporaneous optical light...
A Far Ultraviolet Study of the Old Nova V841 Oph (2005)
Engle, Scott G., Sion, Edward M.
We have carried out a synthetic spectral analysis of archival IUE spectra of the old nova V841 Oph (Nova Oph 1848) taken 15 years apart. The spectra reveal a rising continuum shortward of 1560\AA, a...
The boundary layer of VW Hyi in quiescence (2004)
Godon, Patrick, Sion, Edward M.
In this letter, we suggest that the missing boundary layer luminosity of dwarf novae in quiescence is released mainly in the ultraviolet (UV) as the second component commonly identified in the far...
Far Ultraviolet Observations of the Dwarf Nova VW Hyi in Quiescence (2004)
Godon, Patrick, Sion, Edward M., Cheng, Fu-Hua, Szkody, Paula, Long, Knox S., Froning, Cynthia S.
We present a 904-1183 A spectrum of the dwarf nova VW Hydri taken with the Far Ultraviolet Spectroscopic Explorer during quiescence, eleven days after a normal outburst, when the underlying white...
Gänsicke, Boris T., Szkody, Paula, De Martino, Domitilla, Beuermann, Klaus, Long, Knox S., Sion, Edward M., ...
Brief HST/STIS spectroscopic snapshot exposures of the cataclysmic variables 1RXSJ232953.9+062814, CE315, BZ UMa and EY Cyg reveal very large NV/CIV line flux ratios, similar to those observed in AE...
WZ Sge: FUSE Spectroscopy of the 2001 Outburst (2003)
Long, Knox S., Froning, Cynthia S., Gaensicke, Boris, Knigge, Christian, Sion, Edward M., Szkody, Paula
The short-period cataclysmic variable WZ Sge underwent its first dwarf nova outburst in 23 years in 2001 July. Here we describe 905-1187 Ang. spectra obtained with the Far Ultraviolet Spectroscopic...
Hubble Space Telescope Spectroscopy of V471 Tauri: Oversized K Star, Paradoxical White Dwarf (2001)
O'Brien, M. Sean, Bond, Howard E., Sion, Edward M.
We have used the GHRS onboard the HST to obtain Lyman-alpha spectra of the hot white-dwarf (WD) component of the short-period eclipsing DA+dK2 pre-cataclysmic binary V471 Tauri, a member of the...
Detection of Coronal Mass Ejections in V471 Tauri with the Hubble Space Telescope (2001)
Bond, Howard E., Mullan, D. J., O'Brien, M. Sean, Sion, Edward M.
V471 Tauri, an eclipsing system consisting of a hot DA white dwarf (WD) and a dK2 companion in a 12.5-hour orbit, is the prototype of the pre-cataclysmic binaries. The late-type component is...
Sion, Edward M., Cheng, F. H., Szkody, Paula, Sparks, Warren, Gaensicke, Boris, Huang, Min, ...
We obtained Hubble GHRS medium resolution (G160M grating) phase-resolved spectroscopic observations of the prototype dwarf nova U Geminorum during dwarf nova quiescence, 13 days and 61 days following...
The theory of visual binary orbits and the method of van den Bos : a vectorial approach / (1969)
Thesis (M.A.)--University of Kansas, Physics and Astronomy, 1969.