%R=BibCode %A=Authors %B=Abstract %c=Copyright %D=Date of publication %E=Electronic file %F=Original File %I=Institute and/or Footnotes %J-last page %K=Keywords %T=Title %R 1998PASP..110....1C %F ori/PASPv110n743 %J-1 %T EDITORIAL. %A Cowley Anne %A Hartwick David %I Co-Editors %R 1998PASP..110....2P %F ori/PASPv110n743 %J-2 %T EDITORIAL. %A Percy John R. %I President, Astronomical Society of the Pacific %R 1998PASP..110....3G %F ori/PASPv110n743 %J-26 %T Nucleosynthesis in Classical Novae and Its Contribution to the Interstellar Medium. (Invited Review). %A Gehrz Robert D. %I Department of Astronomy, School of Physics and Astronomy, 116 Church Street, S. E., University of Minnesota, Minneapolis, MN 55455 %A Truran James W. %I Department of Astronomy and Astrophysics, Enrico Fermi Institute, University of Chicago, 933 East 56th Street, Chicago, IL 60637 %A Williams Robert E. %I Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 and %A Starrfield Sumner %I Department of Physics and Astronomy, Arizona State University, P.O. Box 871504, Tempe, AZ 85287-1504 %B Classical novae, explosions that result from thermonuclear runaways (TNRs) on the surfaces of white dwarfs (WDs) accreting hydrogen-rich matter in close binary systems, are sporadically injecting material processed by explosive hydrogen-burning nucleosynthesis into the interstellar medium (ISM). Although novae probably have processed less than ~0.3% of the interstellar matter in the Galaxy, both theoretical and observational evidence suggests that they may be important sources of the nuclides ^7^Li, ^15^N, and ^17^O, as well as the radioactive isotopes ^22^Na and ^26^Al. The latter nuclides are astrophysically important in that they may have been involved in the production of the ^22^Ne (Ne-E) and ^26^Mg enrichments identified in meteoritic inclusions, the composition of which is thought to be representative of the chemical and mineral contents of the primitive solar nebula. These inclusions may be partially composed of dust condensed in nova outbursts. We review theoretical expectations for the yields of various isotopes in nova outbursts and conclude that any of the heavy isotope anomalies attributable to novae are most likely produced by the approximately 25%-33% of novae that occur in systems containing massive (M_*_>1.2 {\em M}_{sun}_) oxygen-neon-magnesium (ONeMg) WDs. We attempt to place quantitative constraints on the degree to which classical novae participate in the production of chemical anomalies, both in the primitive solar system and on a Galactic scale. Diffuse Galactic {gamma}-ray fluxes provide particularly important clues to and constraints on the ^22^Na and ^26^Al yields from novae. Ultraviolet (UV), optical, and infrared (IR) emission-line spectra of classical novae reveal the abundances of some of the gas-phase elements present in the ejecta; recent results are reviewed. We describe how IR observations of novae reveal dust formation and gas-phase line emission and how they distinguish the temporal development of nova explosions on carbon-oxygen (CO) WDs (CO novae) from those on ONeMg WDs (ONeMg or ``neon'' novae). Recent studies show that the ejecta in some novae can be strongly cooled by near- and mid-IR forbidden-line radiation from highly ionized (``coronal'') atomic states. We compare the abundances deduced from recent UV, optical, and IR observations with theoretical predictions, and we suggest that future studies of IR coronal emission lines may provide additional key information. Novae produce only about 0.1% of the Galactic ``stardust'' (dust condensed in stellar outflows), but IR observations show that it may be some of the more interesting dust. Novae appear capable of producing astrophysical dust of virtually every known chemical and mineral composition. We summarize recent IR observations of the dust production scenario in novae and argue that neon novae may lead to the formation of dust grains that carry the Ne-E and ^26^Mg anomalies. %R 1998PASP..110...27R %F ori/PASPv110n743 %J-30 %T {\em BVR} Photometry of Northern Galactic Plane Luminous Stars(1). %A Reed B.Cameron ,(2) %A Carmody Patrick M.,(2,)(3) %A Landy David H.(2,)(3) %I Department of Physics, Alma College, Alma, MI 48801; (reed@alma.edu) %B CCD-based {\em BVR} photometry of 90 stars listed in Volumes II, III, and IV of the Case-Hamburg {\em Catalog of Luminous Stars in the Northern Milky Way} is reported. %I (1) This research was performed at the Lowell Observatory 31 inch telescope, which, under an agreement with Northern Arizona University and the NURO Consortium, is operated 60% of the time as the National Undergraduate Research Observatory. %I (2) Visiting Astronomer, National Undergraduate Research Observatory. %I (3) Undergraduate summer research student, Department of Physics, Alma College. %R 1998PASP..110...31S %F ori/PASPv110n743 %J-38 %T {\em Hubble Space Telescope}/Faint Object Spectrograph Imaging of Wolf 424 AB: Is This Binary a Double Brown Dwarf System?(1). %A Schultz A.B. %A Hart H.M. %A Hershey J.L. %A Hamilton F.C., %A Kochte M. %I Astronomy Programs, Computer Sciences Corporation, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (schultz@stsci.edu), (hart@stsci.edu), (hershey@stsci.edu), (hamilton@stsci.edu), (kochte@stsci.edu) %A Bruhweiler F.C. %I Institute for Astrophysics and Computational Sciences, Department of Physics, Catholic University of America, Washington, DC 20064; (hrsfred@hrs.gsfc.nasa.gov) %A Benedict G.F. %I McDonald Observatory, University of Texas, Austin, TX 78712-1083; (fritz@dorrit.as.utexas.edu) %A Caldwell John %A Cunningham C. %I York University, Toronto, M3J 1P3 Ontario, Canada; (caldwell@nereid.sal.phys.yorku.ca), (ccc@nereid.sal.ists.ca) %A Franz O.G. %I Lowell Observatory, Flagstaff, AZ 86001; (ogf@lowell.edu) %A Keyes C.D. %I Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (keyes@stsci.edu) and %A Brandt J.C. %I LASP, University of Colorado, Boulder, CO 80309-0392; (brandt@lyrae.colorado.edu) %B The low-mass binary system Wolf 424 AB (GJ 473 AB) was spatially resolved in an image obtained on 1996 April 16 with the imaging mode of the {\em Hubble Space Telescope} Faint Object Spectrograph. The separation was measured to be 0".42+/-0".03 at a position angle of 353{deg}.2+/-2{deg}.5. The new measurement was combined with previously published orbital positions to update the orbital elements and obtain an estimate of the total mass. Spectroscopy and photometry of these objects suggest they are nearly equal in mass. The derived orbital solution, using all of the observations since 1938 appropriately weighted, yields a total mass of m_1_+m_2_ of 0.143 {\em M}_{sun}_, and component masses of ~0.07 {\em M}_{sun}_, just under the theoretical limit for a brown dwarf. An alternate orbital solution derived solely from speckle observations since 1986 and the Faint Object Spectrograph image yields a total mass of 0.232 {\em M}_{sun}_, placing both components well above the brown-dwarf limit. The mass depends on the value for the semimajor axis, which is controlled in the latter solution by an optical speckle observation made near the last period of maximum separation. Further high-resolution observations during the upcoming maximum separation, and through the next secondary maximum, are needed to constrain the orbit. %K Stars: Binaries: General %K Stars: Low-Mass, Brown Dwarfs %I (1) Based on observations with the NASA/ESA {\em Hubble Space Telescope}, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. %R 1998PASP..110...39N %F ori/PASPv110n743 %J-46 %T Rotationally Broadened Synthetic Spectra for {\em HST} and {\em IUE} Observations of Exposed White Dwarfs in Cataclysmic Variables(1). %A Nguyen Quyen %A Fabian Dirk %A Belle Kunegunda %A Huang M., %A Sion E.M. %I Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 %B In many dwarf novae during quiescence, the underlying white dwarf dominates the flux in the far ultraviolet. By observing these exposed degenerate stars with the {\em Hubble Space Telescope} Goddard High Resolution Spectrograph and Faint Object Spectrograph ({\em HST} GHRS and FOS), the white-dwarf rotation rates can be determined or constrained by fitting synthetic spectra broadened by rotation. Using TLUSTY and SYNSPEC, we present a grid of rotationally broadened white-dwarf synthetic spectra, convolved with the resolution of the {\em HST} GHRS (G140L, G160M), FOS (G130H), and {\em IUE} low-resolution short-wavelength prime (SWP) spectra, computed for {\rf log}g=8, solar composition, T_eff_=15,000, 25,000, and 50,000 K, and rotational velocities of 0-5000 km.s^-1^. We examine the predicted appearance of accreted solar-composition white-dwarf atmospheres in the context of determining or constraining the white-dwarf rotational velocities. We present model grids that demonstrate this capability. We present the first application of these grids to the SWP low-resolution spectra of the white dwarf in the nova-like variable TT Ari, exposed during the very low brightness state of that system. We also rule out the possibility that the absence of Ly{alpha} absorption in many cataclysmic variables in quiescence (specifically those containing white dwarfs with T_eff_=15,000-20,000 K) could be due to rotational velocities of the white dwarf near breakup. %I (1) Based on observations with the NASA/ESA {\em Hubble Space Telescope} obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. %R 1998PASP..110...47B %F ori/PASPv110n743 %J-52 %T An {\em IUE} Spectroscopic Study of the Ultra-Short-Period Dwarf Nova T Leonis in Outburst. %A Belle K. %A Nguyen Q. %A Fabian D. %A Sion E.M., %A Huang M. %I Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085; (dfabian@monet.vill.edu), (emsion@ucis.vill.edu), (huang@ucis.vill.edu) %B The {\em IUE} archive contains numerous low-resolution spectra of dwarf novae in outburst but relatively little synthetic spectral analyses of them using realistic accretion disk models with spectral lines. We have examined a series of previously unstudied archival {\em IUE} low-resolution short-wavelength prime spectra of the SU UMa-type ultra-short-period dwarf nova T Leonis, obtained continuously through a single dwarf nova outburst. We describe its outburst spectra, characterizing its metallic absorption-line spectrum and the shape of its energy distribution. We estimate a terminal wind velocity of 2500 km.s^-1^ and report possible evidence of wind variability on timescales of roughly 2 hr, although orbital phase variations cannot be ruled out. We have constructed a grid of optically thick accretion disk models for white dwarf masses 0.6 and 1.0 {\em M}_{sun}_, accretion rates 10^-11^-10^-7^ {\em M}_{sun}_.yr^-1^, and disk inclination angles of 40{deg} and 80{deg}. We carry out preliminary synthetic accretion disk spectral fitting of T Leo and present the results. Our best-fitting model to a co-addition of three spectra with similar S/N yields M_WD_=0.6 M_{sun}_, i=~40{deg}, M{dot}=~10^-9^ M_{sun}_.yr^-1^ with an inner disk temperature of 30,000 K and an outer disk temperature of 14,000 K. These results compare favorably with analyses of optical spectra of T Leo in outburst, suggesting that a similar application to other far-UV spectra of dwarf novae in outburst, with a finer grid of disk models, should prove profitable. %R 1998PASP..110...53G %F ori/PASPv110n743 %J-59 %T Frequency of Binaries in the Open Cluster Trumpler 14. %A Garc\'ia Beatriz ,(1,)(2) %A Malaroda Stella ,(3) %A Levato Hugo (1) %I Complejo Astron\'omico El Leoncito, CC 467, 5400 San Juan, Argentina; (Cricyt@lanet.losandes.com.ar), (malaroda@castec.edu.ar), (levato@castec.edu.ar) %A Morrell Nidia (1,)(4,)(5) %I Facultad de Ciencias Astron\'omicas y Geof\'isicas de la U.N.L.P. Paseo del Bosque s/n. 1900 La Plata, Argentina; (nidia@facglp.fcaglp.unlp.edu.ar) %A Grosso M\'onica (6) %I Complejo Astron\'omico El Leoncito, CC 467, 5400 San Juan, Argentina; (mgrosso@castec.edu.ar) %B We present new spectroscopic data for nine objects among the brightest stars in the field of the open cluster Trumpler 14. Radial velocities were measured from around 80 new spectrograms in order to provide more information about the binary nature of these objects. From this material, we conclude that at least two of the stars in the sample are radial-velocity variables, one of them showing double He I features. %I (1) Member of the Carrera del Investigador Cient\'ifico del Consejo Nacional de Investigaciones Cient\'ificas y T\'ecnicas de la Rep\'ublica Argentina. %I (2) Now at the Centro Regional de Investigaciones Cient\'ificas y T\'ecnicas, CC 131, 5500 Mendoza, Argentina. %I (3) Member of the Carrera del Investigador Cient\'ifico de la Comisi\'on de Investigaciones Cient\'ificas de la Provincia de Buenos Aires. %I (4) Visiting Astronomer, Cerro Tololo Inter-American Observatory. CTIO is operated by AURA, Inc., under contract to the National Science Foundation. %I (5) Visiting Astronomer, Complejo Astron\'omico El Leoncito. CASLEO is operated under agreement of the Universidad Nacional de La Plata, the Universidad Nacional de C\'ordoba, the Universidad Nacional de San Juan, and CONICET. %I (6) Member of the Consejo Nacional de Investigaciones Cient\'ificas y T\'ecnicas. %R 1998PASP..110...60G %F ori/PASPv110n743 %J-67 %T Molecular Hydrogen along Two Lines of Sight through the Large Magellanic Cloud. %A Gunderson Kurt S. %I Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309; (gunderso@casa.colorado.edu) %A Clayton Geoffrey C. %I Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803; (gclayton@fenway.phys.lsu.edu) %A Green James C. %I Center for Astrophysics and Space Astronomy, University of Colorado, Boulder, CO 80309; (jgreen@casa.colorado.edu) %B We have remeasured the H_2_ column densities along lines of sight to the Large Magellanic Cloud (LMC) using spectra taken by the Hopkins Ultraviolet Telescope (HUT). Three lines of sight were analyzed using the pair method and previously determined Fitzpatrick & Massa extinction parameters to allow H_2_ absorption models to be fitted. Substantial improvements over the values first reported by Clayton et al. were made for two of the three lines of sight. Comparisons between LMC and Galactic environments suggest that the factors which lead to extinction curve variations (e.g., metallicity or shocks) do not affect the efficiency of H_2_ formation on the surfaces of the dust grains: N_H2_MEB-V values are approximately the same in both galaxies despite large differences in N_H I_MEB-V. %R 1998PASP..110...68R %F ori/PASPv110n743 %J-78 %T The Goddard High Resolution Spectrograph: Post-COSTAR Characteristics. %A Robinson R.D. %A Ake T.B. %I Astronomy Programs, Computer Sciences Corporation, Code 681/CSC, Goddard Space Flight Center, Greenbelt, MD 20771; (hrsrobinson@hrs.gsfc.nasa.gov), (hrsake@hrs.gsfc.nasa.gov) %A Lindler D.J. %I Advanced Computer Concepts, Code 681, NASA/Goddard Space Flight Center, Greenbelt, MD 20771; (hrslindler@hrs.gsfc.nasa.gov) %A Heap S.R. %A Carpenter K.G. %A Leckrone D.S. %A Maran S.P., %A Smith A.M. %I Laboratory for Astronomy and Solar Physics, Code 681 NASA/Goddard Space Flight Center, Greenbelt, MD 20771; (hrsheap@hrs.gsfc.nasa.gov), (hrscarpenter@hrs.gsfc.nasa.gov), (hrsleckrone@hrs.gsfc.nasa.gov), (hrsmaran@hrs.gsfc.nasa.gov), (hrssmith@hrs.gsfc.nasa.gov) %A Brandt J.C. %I Laboratory for Atmospheric and Space Physics, Campus Box 392, University of Colorado, Boulder, CO 80309-0392; (brandt@lyrae.colorado.edu) %A Beaver E.A. %I Center for Astrophysics and Space Sciences, C-011, University of California, San Diego, La Jolla, CA 92093-0111 %A Boggess A. %I Code 440, NASA/Goddard Space Flight Center, Greenbelt, MD 20771; (hrsboggess@stars.gsfc.nasa.gov) %A Ebbets D.C. %I Ball Aerospace Systems Group, P. O. Box 1062, AR1, Boulder, CO 80306; (ebbets@lyrae.colorado.edu) %A Hutchings J.B. %I Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria, BC, V8X 4M6, Canada; (hutchings@dao.nrc.ca) %A Jura M. %I Department of Astronomy, University of California, Los Angeles, CA 90024; (jura@bonnie.astro.ucla.edu) %A Linsky J.L. %I Joint Institute for Laboratory Astrophysics, University of Colorado and National Institute of Standards and Technology, Boulder, CO 80309-0440; (jlinsky@jila.colorado.edu) %A Savage B.D. %I Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706; (savage@madraf.astro.wisc.edu) %A Trafton L.M. %I MacDonald Observatory and Astronomy Department, University of Texas, Austin, TX 78712; (lmt@astro.as.utexas.edu) %A Walter F.M. %I Department of Earth and Space Sciences, State University of New York, Stony Brook, NY 11794-2100; (fwalter@ccmail.sunysb.edu) %A Weymann R.J. %I Observatories of the Carnegie Institute of Washington, 812 Santa Barbara Street, Pasadena, CA 91101; (rjw@ociw.edu) %B We review changes to the characteristics of the Goddard High Resolution Spectrograph (GHRS) which resulted from the installation of the Corrective Optics Space Telescope Axial Replacement (COSTAR) on the {\em Hubble Space Telescope}. The introduction of two new optical elements into the light path altered the spectral distribution of the light, decreasing the amount of light striking the instrument by about 30% at wavelengths greater than 1200 {AA} and effectively eliminated all radiation at wavelengths less than 1130 {AA}. However, at the longer wavelengths the improved focus offset this loss when the Large Science Aperture (LSA) was used and increased the overall throughput of the Small Science Aperture (SSA) by a factor of 2. The improved focus also enhanced the spectral resolution of LSA observations and improved the ability of the instrument to observe in crowded fields. %R 1998PASP..110...79F %F ori/PASPv110n743 %J-85 %T The FAST Spectrograph for the Tillinghast Telescope. %A Fabricant Daniel %A Cheimets Peter %A Caldwell Nelson , %A Geary John %I Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138; (dfabricant@cfa.harvard.edu), (pcheimets@cfa.harvard.edu), (ncaldwell@cfa.harvard.edu), (jgeary@cfa.harvard.edu) %B We describe a high-throughput optical spectrograph that has been in operation at the Cassegrain focus of the 1.5-m Tillinghast reflector since 1994 January. FAST has a 3'-long slit and is typically operated at resolutions between 1 and 6 {AA}. With a collimated beam diameter of ~100 mm, FAST (with a 300 lines.mm^-1^ grating and a 1".5-wide slit) offers 4000 {AA} of spectral coverage at 3 {AA} resolution. FAST's optics are primarily reflective, are adequately sized to prevent vignetting, and use high-performance coatings. The high measured system peak efficiency of 26% (fraction of light incident on the primary detected at the CCD) demonstrates that the throughput of reflective optics can be quite competitive with that of refractive optics. FAST's structure is constructed from graphite-epoxy composite panels, which have an excellent stiffness-to-weight ratio and low thermal expansion, resulting in low flexure and excellent focus stability. %R 1998PASP..110...86F %F ori/PASPv110n743 %J-91 %T Focusing on a Turbulent Layer: Principle of the ``Generalized SCIDAR''. %A Fuchs Alain %I D\'epartement d'Astrophysique, CNRS UMR 6525, Universit\'e de Nice-Sophia Antipolis, 06108 Nice, France; (fuchs@ayalga.unice.fr) %A Tallon Michel %I CRAL, Observatoire de Lyon, CNRS UMR 5574, 69561 Saint-Genis-Laval, France; (mtallon@obs.univ-lyon1.fr) %A Vernin Jean %I D\'epartement d'Astrophysique, CNRS UMR 6525, Universit\'e de Nice-Sophia Antipolis, 06108 Nice, France; (vernin@ayalga.unice.fr) %B During the last two decades, much effort has been put into the remote sensing of atmospheric turbulent layers, using optical devices. The main scientific interest concerns optical path fluctuations relevant to communication and astronomy and the widening of our understanding of atmospheric physics. Here we describe an original technique that involves moving a virtual plane of analysis in the atmosphere. Using this technique, a simple optical combination allows us to explore the atmosphere, wiping out a particular layer while distant layers located beneath or above are reinforced. When combined with the SCIDAR technique, this phenomenon leads to the ``generalized SCIDAR'' concept, allowing turbulence profiles to be remotely assessed throughout the whole atmosphere, including the boundary layer. The potential of this new concept is shown in a laboratory experiment using a vein to simulate an atmospheric turbulent layer. %R 1998PASP..110...92K %F ori/PASPv110n743 %J-92 %T Studies of Substructure in Galaxy Clusters: A Two-dimensional Analysis. (DISSERTATION SUMMARY). %A Kriessler Jeffrey R. %I Thesis work conducted at Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824Current address: Department of Astronomy, University of Minnesota, 116 Church Street S. E., Minneapolis, MN 55455; (jeffk@isis.spa.umn.edu)Ph.D. dissertation directed by: Timothy C. BeersPh.D. degree awarded: 1997