%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..110.1119S %F ori/PASPv110n752 %J-1131 %T {\em IRAS} Detections of Metal-poor Red Giants. %A Smith, Graeme H. %I University of California Observatories/Lick Observatory, University of California, Santa Cruz, CA 95064; (graeme@ucolick.org) %B A number of relatively bright metal-poor red giants from the HD and BD catalogs are found to have been detected by the {\em IRAS} satellite. Data for these stars have been retrieved from the {\em IRAS} Point Source Catalog (PSC) and/or the Faint Source Catalog (FSC). The majority of metal-poor giants in these samples fall along relatively well-defined sequences in plots of V-[12] versus B-V and V-I; for these stars, the 12 {mu}m flux detected is presumed to arise from the photosphere. Only a subset of stars detected at 12 {mu}m were detected at 25 {mu}m; these are displayed in a plot of [12]-[25] versus V-[12]. There are a small number of giants that exhibit notable 12 and/or 25 {mu}m excesses relative to the mean sequences defined by the bulk of the sample. Those stars with the most unambiguous evidence for infrared excesses are variable stars, either long-period or semiregular variables or RV Tauri stars. As such, those stars exhibiting infrared excesses in the metal-poor giant sample are likely in the asymptotic giant branch (AGB) or post-AGB phase of evolution. There is no clear evidence for nonvariable first-ascent red giants having been detected among the infrared-excess stars. In fact, some metal-poor red giants known to exhibit outflows in their chromospheres do not show infrared excesses. A Population II star ascending the red giant branch for the first time appears to have too low a mass-loss rate to be recognizable as an infrared-excess star in the {\em IRAS} PSC or FSC. %K Stars: Circumstellar Matter %K Stars: AGB and Post-AGB %K Stars: Mass Loss %K Stars: Population II %R 1998PASP..110.1132P %F ori/PASPv110n752 %J-1147 %T Late Evolution of Cataclysmic Variables. %A Patterson, Joseph %I Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; (jop@astro.columbia.edu) %B We study the evolution of hydrogen-rich cataclysmic variables (CVs) near minimum orbital period at ~78 minutes. As has been known for many years, these are among the most intrinsically common CVs, but they hide fairly well because of their faintness and low incidence of eruptions. We discuss their number and observational signatures, paying special attention to those that may have passed minimum orbital period--the ``period bouncers.'' The status of binaries near minimum period is best determined by the mass ratio, and this is best constrained by measuring the accretion disk precession frequency, because that frequency is readily accessible to observation and proportional to the secondary star's mass. This method reveals four stars that are good candidates to have survived period bounce; two appear to have secondaries as puny as 0.02 M_{sun}_. But each star can have bounced only recently if at all. {\em There is still no strong evidence of any long era of evolution in a state of increasing period.} This conflicts sharply with discussions of observational data that have identified dozens of known CVs with this state. The total space density of cataclysmic variables is ~10^-5^ pc^-3^, with short-period systems constituting ~75% of the total. Both estimates are far less than predicted by simple theories of evolution. It is probably necessary to have some means of destroying CVs before they reach the predicted very high space densities. This can be done by invoking an angular momentum loss mechanism that does not quickly subside as the mass ratio becomes very low. %K Stars: Novae, Cataclysmic Variables %K Stars: Evolution %R 1998PASP..110.1148T %F ori/PASPv110n752 %J-1155 %T Superhumps in Cataclysmic Binaries. XIV. V592 Cassiopeiae. %A Taylor, Cynthia J. (1) %A Thorstensen, John R. (1) %A Patterson, Joseph (2) %A Fried, Robert E. (3) %A Vanmunster, Tonny (4) %A Harvey, David A. (5) %A Skillman, David R. (6) %A Jensen, Lasse (7) %A Shugarov, Sergei (8) %B We report a spectroscopic and photometric study of the novalike variable V592 Cassiopeiae (=LS I 55{deg} 8). The spectrum is that of a typical UX UMa-type star, with weak, narrow Balmer emission superposed on broad absorption. The 0.1-2.2 {mu}m flux distribution also looks fairly normal, suggesting disk accretion at ~10^-8^ {\em M}_{sun}_.yr^-1^ and a distance of 330 pc. The emission lines move with {\em P} = 0.115063(1) days, which is presumably the underlying orbital period of the binary. Photometry reveals a different period, namely, 0.12228(1) days. The presence of this wave in a short-period cataclysmic variable, and the value of the period excess at 6.3%, suggests identification as a ``permanent superhump.'' After subtraction of this large signal, the residual time series appears to contain a weak feature at 0.11193(5) days. The star evidently shows positive and negative superhumps simultaneously. Its binary period puts it among a modest number of nonmagnetic cataclysmic variables occupying the 2-3 hr period ``gap.'' %K Stars: Binaries: Close %K Stars: Novae, Cataclysmic Variables %K Stars: Variables: Other %I (1) Department of Physics and Astronomy, Dartmouth College, 6127 Wilder Laboratories, Hanover, NH 03755; (cynthia.j.taylor@dartmouth.edu), (thorstensen@dartmouth.edu). %I (2) Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027; (jop@astro.columbia.edu). %I (3) Braeside Observatory, P.O. Box 906, Flagstaff, AZ 86002; (captain@braeside.org). %I (4) Center for Backyard Astrophysics (Belgium), Walhostraat 1A, B-3401 Landen, Belgium; (Tonny.Vanmunster@advalvas.be). %I (5) Center for Backyard Astrophysics (West), 1552 West Chapala Drive, Tucson, AZ 85703; (dharvey@comsoft-telescope.com). %I (6) Center for Backyard Astrophysics (East), 9517 Washington Avenue, Laurel, MD 20723; (dskillman@home.com). %I (7) Center for Backyard Astrophysics (Denmark), S{oslash}ndervej 38, DK-8350 Hundslund,, Denmark; (teist@image.dk). %I (8) Sternberg Astronomical Institute, Moscow State University, Universitetsky Prospect 13, 119899 Moscow, Russia; (shugarov@sai.msu.su). %R 1998PASP..110.1156M %F ori/PASPv110n752 %J-1163 %T CCD Photometry of the High-Amplitude {delta} Scuti Stars V798 Cygni and V831 Tauri. %A Musazzi, F. %A Poretti, E., %A Covino, S. %I Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate, Italy; (poretti@merate.mi.astro.it), (covino@merate.mi.astro.it) and %A Ferro, A.Arellano %I Departamento de Astronom\'ia, Universidad de Guanajuato, Apdo Postal 144, Guanajuato, Gto. M\'exico 36000; (armando@astro.ugto.mx) %B New CCD measurements of the two high-amplitude {delta} Scuti stars V798 Cyg and V831 Tau were carried out. The double-mode pulsation of V798 Cyg is demonstrated beyond any doubt. The f_1_Mf_2_ ratio of 0.800 is confirmed to be related to the unusual shape of the f_1_ light curve. The properties of the Fourier parameters were revisited also by considering the new light curve of V831 Tau. In particular, the classical double-mode pulsators cannot fill the gap in the R_21_ distribution. Two new variable stars were discovered in the field of V798 Cyg. %K Stars: Variables: {delta} Scuti %K Methods: Data Analysis %K Stars: Oscillations %R 1998PASP..110.1164S %F ori/PASPv110n752 %J-1171 %T Photometric Calibration of Stars in the Fields of Selected BL Lacertae Objects and Quasars. %A Smith, Paul S. %I National Optical Astronomy Observatories, Kitt Peak National Observatory, P.O. Box 26732, Tucson, AZ 85726-6732; (psmith@noao.edu) and %A Balonek, Thomas J. %I Department of Physics and Astronomy, Colgate University, Hamilton, NY 13346-1398; (tbalonek@center.colgate.edu) %B We present the results of {\em UBVRI} photometry of stars in the fields of 13 BL Lacertae objects and quasars. The calibrated stars are intended to facilitate photoelectric and CCD differential photometry of these highly variable active galactic nuclei (AGNs). The magnitudes of most of the stars were measured on more than two occasions, and we provide two to five stars per field. Several stars are common to those calibrated by previous observers, although the earlier efforts do not cover all five bandpasses. Our results for these stars are typically in close agreement with previous measurements obtained using common filters. In addition, we present {\em UBVRI} magnitudes for stars in the fields of four AGNs (CTA 26, 0716+332, OV-236, and PKS 2345-167) with no previously published comparison stars. %K Galaxies: BL Lacertae Objects: General %K Galaxies: Photometry %K Galaxies: Quasars: General %R 1998PASP..110.1172G %F ori/PASPv110n752 %J-1182 %T The Open Cluster NGC 7789. I. Radial Velocities for Giant Stars. %A Gim, Munhwan %I University of Victoria, Department of Physics and Astronomy, Victoria, BC V8W 3P6, Canada; (gim@uvastro.phys.uvic.ca) %A Hesser, James E. %A McClure, Robert D., %A Stetson, Peter B. %I National Research Council, Herzberg Institute of Astrophysics, Dominion Astrophysical Observatory 5071 West Saanich Road, Victoria, BC V8X 4M6, Canada; (james.hesser@hia.nrc.ca), (robert.mcclure@hia.nrc.ca), (peter.stetson@hia.nrc.ca) %B A total of 597 radial velocity observations for 112 stars in the ~1.6 Gyr old open cluster NGC 7789 have been obtained since 1979 with the radial velocity spectrometer at the Dominion Astrophysical Observatory. The mean cluster radial velocity is -54.9+/-0.12 km.s^-1^ and the dispersion is 0.86 km.s^-1^, from 50 constant velocity stars selected as members from this radial velocity study and the 1981 proper motion study of McNamara & Solomon. Twenty-five stars (32%) among 78 members are possible radial velocity variable stars, but no orbits are determined because of the sparse sampling. Seventeen stars are radial velocity nonmembers, while the membership estimates of six stars are uncertain. There is a hint that the observed velocity dispersion falls off at large radius. This may due to the inclusion of long-period binaries preferentially in the central area of the cluster. The known radial velocity variables also seem to be more concentrated toward the center than members with constant velocity. Although this is significant at only the 85% level, when combined with the similar result of Raboud & Mermilliod for three other clusters, the data strongly support the conclusion that mass segregation is being detected. %K Galaxy: Open Clusters and Associations: Individual: NGC Number: NGC 7789 %K Stars: Binaries: Spectroscopic %K Techniques: Radial Velocities %R 1998PASP..110.1183W %F ori/PASPv110n752 %J-1204 %T The Space Telescope Imaging Spectrograph Design(1). %A Woodgate, B.E. (2) %A Kimble, R.A. (3) %A Bowers, C.W. (3) %A Kraemer, S. (3) %A Kaiser, M.E. (3) %A Danks, A.C. (3) %A Grady, J.F. (3) %A Loiacono, J.J. (3) %A Brumfield, M. (3) %A Feinberg, L. (3) %A Gull, T.R. (3) %A Heap, S.R. (3) %A Maran, S.P. (3) %A Lindler, D. (3) %A Hood, D. (4) %A Meyer, W. (4) %A VanHouten, C. (4) %A Argabright, V. (4) %A Franka, S. (4) %A Bybee, R. (4) %A Dorn, D. (4) %A Bottema, M. (4) %A Woodruff, R. (4) %A Michika, D. (4) %A Sullivan, J. (4) %A Hetlinger, J. (4) %A Ludtke, C. (4) %A Stocker, R. (4) %A Delamere, A. (4) %A Rose, D. (4) %A Becker, I. (4) %A Garner, H. (4) %A Timothy, J.G. (5) %A Blouke, M. (6) %A Joseph, C.L. (7) %A Hartig, G. (8) %A Green, R.F. (9) %A Jenkins, E.B. (10) %A Linsky, J.L. (11) %A Hutchings, J.B. (12) %A Moos, H.W. (13) %A Boggess, A. (14) %A Roesler, F. (15) %A Weistrop, D. (16) %B The Space Telescope Imaging Spectrograph (STIS) instrument was installed on the {\em Hubble Space Telescope} ({\em HST}) during the second servicing mission, in 1997 February. Four bands cover the wavelength range of 115-1000 nm, with spectral resolving powers between 26 and 200,000. Camera modes are used for target acquisition and deep imaging. Correction for {\em HST}'s spherical aberration and astigmatism is included. The 115-170 nm range is covered by a CsI MAMA (Multianode Microchannel Array) detector and the 165-310 nm range by a Cs_2_Te MAMA, each with a format of 2048x2048 pixels, while the 305-555 and 550-1000 nm ranges are covered by a single CCD with a format of 1024x1024 pixels. The multiplexing advantage of using these two-dimensional detectors compared with the 1x512 pixel detectors of the first-generation spectrographs is 1 or 2 orders of magnitude, depending on the mode used. The relationship between the scientific goals and the instrument specifications and design is discussed. %K Instrumentation: Spectrographs %I (1) This paper is dedicated to Murk Bottema, the master optical designer who guided the STIS design until his untimely death in 1993. %I (2) NASA Goddard Space Flight Center, Code 6681, Greenbelt, MD 20771; (woodgate@s2.gsfc.nasa.gov). %I (3) NASA Goddard Space Flight Center, Greenbelt, MD 20771. %I (4) Ball Aerospace Technology Corporation, Boulder, CO 80301. %I (5) Centre for Research in Earth and Space Science (CRESS), York University, North York, Ontario, M2N 5X2, Canada. %I (6) SITe Corporation, Beaverton, OR 97006. %I (7) Physics Department, Rutgers University, New Brunswick, NJ 08903. %I (8) Space Telescope Science Institute, Baltimore, MD 21218. %I (9) National Optical Astronomical Observatories, Tucson, AZ 85726. %I (10) Princeton University Observatory, Princeton, NJ 08544. %I (11) JILA, University Colorado, and NIST, Boulder, CO 80309. %I (12) Dominion Astrophysical Observatory, Victoria, British Columbia, V8X 4M6, Canada. %I (13) Johns Hopkins University, Baltimore, MD 21218. %I (14) Catholic University of America, Washington, DC 20064. %I (15) University of Wisconsin, Madison, WI 53706. %I (16) University of Nevada Las Vegas, Las Vegas, NV 89154. %R 1998PASP..110.1205G %F ori/PASPv110n752 %J-1215 %T The Performance and Scientific Rationale for an Infrared Imaging Fourier Transform Spectrograph on a Large Space Telescope. %A Graham, James R. %I Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720; (jrg@astro.berkeley.edu) %A Abrams, Mark %I ITT Aerospace/Communications Division, 1919 West Cook Road, P.O. Box 3700, Fort Wayne, IN 46801; (mcabrams@itt.com) %A Bennett, C. %I Lawrence Livermore National Laboratory, MS L-043, P.O. Box 808, Livermore, CA 94550; (bennett2@llnl.gov) %A Carr, J. %I Naval Research Laboratory, Code 7217, 4555 Overlook Avenue, Washington, DC 20375; (carr@mriga.nrl.navy.mil) %A Cook, K. %I Lawrence Livermore National Laboratory, MS L-041, P.O. Box 808, Livermore, CA 94550; (kcook@llnl.gov) %A Dey, A. %I Department of Physics and Astronomy, The Johns Hopkins University, 3400 N. Charles Street, Baltimore, MD 21218; (dey@pha.jhu.edu) %A Najita, J. %I Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (najita@stsci.edu) and %A Wishnow, E. %I Lawrence Livermore National Laboratory and Space Sciences Laboratory, University of California Berkeley, MS L-401, P.O. Box 808, Livermore, CA 94550; (wishnow@llnl.gov) %B We describe a concept for an imaging spectrograph for a large orbiting observatory such as NASA's proposed Next Generation Space Telescope (NGST) based on an imaging Fourier transform spectrograph (IFTS). An IFTS has several important advantages that make it an ideal instrument to pursue the scientific objectives of NGST. We review the operation of an IFTS and make a quantitative evaluation of the signal-to-noise performance of such an instrument in the context of NGST. We consider the relationship between pixel size, spectral resolution, and diameter of the beam splitter for imaging and nonimaging Fourier transform spectrographs and give the condition required to maintain spectral modulation efficiency over the entire field of view. We give examples of scientific programs that could be performed with this facility. %K Instrumentation: Interferometers %K Instrumentation: Spectrographs %K Techniques: Interferometric %K Techniques: Spectroscopic %R 1998PASP..110.1216A %F ori/PASPv110n752 %J-1234 %T Sampling and Background Subtraction in Fiber-Lenslet Integral Field Spectrographs. %A Allington-Smith, Jeremy %A Content, Robert %I Astronomical Instrumentation Group, University of Durham, South Road, Durham DH1 3LE, England, UK; (j.r.allington-smith@durham.ac.uk), (robert.content@durham.ac.uk) %B We describe the principle of integral field spectrographs employing fiber-lenslet technology. By reference to instruments which we are constructing, we estimate the spatial and spectral resolution that can be obtained. We show that overlapping between light from adjacent elements at the slit, which is desirable in order to maximize the number of elements and hence the field size, has negligible effect on resolution. We describe different strategies for background subtraction, taking account of the special characteristics of this type of system and compensating for manufacturing defects. We also show how background subtraction may be done when an adaptive optics system is used to feed the integral field spectrograph. We show how these principles have been applied to a fiber-lenslet design for the integral field unit of the GEMINI Multiobject Spectrographs and related instruments. %K Instrumentation: Spectrographs %K Techniques: Spectroscopic %R 1998PASP..110.1235R %F ori/PASPv110n752 %J-1248 %T Scintillation Reduction Method for Photometric Measurements. %A Ryan, P. %I Air Force Research Lab/DES Starfire Optical Range, 3550 Aberdeen Avenue SE, Kirland Air Force Base, NM 87117-5776; (ryanp@plk.af.mil) %A Sandler, D. (1) %I ThermoTrex Corporation, 10455 Pacific Center Court, San Diego, CA 92121; (dsandler@thermotrex.com) %B We explore the reduction of scintillation via differencing signals from binary stars. Theory has been extended to include temporal and angular separation effects simultaneously. For meter-class telescopes, scintillation for a 2" binary is reduced by greater than a factor of 3. Aperture averaging for differential scintillation had a D^-1.4+/-0.1^ dependence for exposure times {<=}0.25 s versus D^-1.1+/-0.1^ for absolute scintillation. For 1.5 m diameter telescopes, the influence of binary separation on differential scintillation for {theta}<5" went as {theta}^0.6^ for instantaneous scintillation and rose slightly with exposure time. If the deconvolution problem can be solved, differencing signals from binary stars offers the potential for increased photometric accuracy. %K Techniques: Photometric %I (1) Center for Astronomical Adaptive Optics, Steward Observatory, University of Arizona, Tucson, AZ 85721. %R 1998PASP..110.1249P %F ori/PASPv110n752 %J-1249 %T Elliptical Galaxies: Structure, Stellar Content, and Evolution . (Dissertation Summary). %A Pahre, Michael A. %I Current address: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Mail Stop 20, Cambridge, MA 02138; (mpahre@cfa.harvard.edu)Thesis work conducted at Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125Ph.D. thesis directed by S. G. Djorgovski; Ph.D. degree awarded 1998 %K Galaxies: Abundances %K Galaxies: Elliptical and Lenticular, cD %K Galaxies: Evolution %K Galaxies: Fundamental Parameters %K Galaxies: Photometry %K Galaxies: Stellar Content %K infrared: galaxies %R 1998PASP..110.1250H %F ori/PASPv110n752 %J-1250 %T Clustering of Galaxies in Pisces-Perseus: Structural Order and Spatial Correlations. (Dissertation Summary). %A Haque-Copilah, Shirin %I Current address: Department of Physics, University of the West Indies, St. Augustine, Trinidad, West Indies; (haqc0019@centre.uwi.tt)Thesis work conducted at Department of Astronomy, University of Virginia, and Department of Physics, University of the West IndiesPh.D. thesis directed by William Saslaw and Anthony Achong; Ph.D. degree awarded 1998 %K Galaxies: Evolution %K Galaxies: Clusters: General %K Cosmology: Large-Scale Structure of Universe %R 1998PASP..110.1251S %F ori/PASPv110n752 %J-1251 %T White Dwarfs in Wide Binaries and the Age of the Galaxy. (Dissertation Summary). %A Smith, J.A. %I Current address: Department of Physics, University of Michigan, 2071 Randall Lab, 500 East University, Ann Arbor, MI 48109; (jasmith@sdss1.physics.lsa.umich.edu)Thesis work conducted at Department of Physics and Spaces Sciences, Florida Institute of TechnologyPh.D. thesis directed by T. D. Oswalt; Ph.D. degree awarded 1997 %K Galaxy: solar neighborhood %K stars: binaries: general %K stars: luminosity function %K stars: white dwarfs %R 1998PASP..110.1252I %F ori/PASPv110n752 %J-1253 %T The Low Surface Brightness Universe: IAU Colloquium 171(1). (Conference Highlights). %A Impey, Chris %I University of Arizona %I (1) Conference was held in Cardiff, Wales, UK, in 1998 July. Proceedings will be edited by J. I. Davies, C. D. Impey, and S. Phillipps and published in the {\em ASP Conference Series}. %R 1998PASP..110.1254S %F ori/PASPv110n752 %J-1254 %T BL Lacertae Phenomenon(1). (Conference Highlights). %A Sillanp\"a\"a, Aimo %A Takalo, Leo O. %I Tuorla Observatory %I (1) Conference was held in Turku, Finland, in 1998 June. Proceedings will be edited by A. Sillanp\"a\"a & L. O. Takalo and published in the {\em ASP Conference Series}. %R 1998PASP..110.1255S %F ori/PASPv110n752 %J-1255 %T Precise Stellar Radial Velocities(1). (Conference Highlights). %A Scarfe, C.D. %A Hearnshaw, J.B. %I University of Victoria and University of Canterbury %I (1) Conference was held in Victoria, British Columbia, Canada, in 1998 June. Proceedings will be edited by John Hearnshaw and Colin Scarfe and published in the {\em ASP Conference Series}. %R 1998PASP..110.1256S %F ori/PASPv110n752 %J-1258 %T The 11th European Workshop on White Dwarfs(1). (Conference Highlights). %A Sion, Edward M. %I Villanova University %I (1) Conference was held in Troms{oslash}, Norway, in 1998 July. Proceedings will be edited by Jan-Erik Solheim and published in the {\em ASP Conference Series}.