%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...93S %F ori/PASPv110n744 %J-97 %T V Crateris: Photometric Elements. %A Sarma M.B.K. %A Vivekananda Rao P. %I Centre for Advanced Study in Astronomy, Osmania University, Hyderabad-500 007 India;(1) (mbks@ouastr.ernet.in), (pvr@ouastr.ernet.in) %B The analysis of the photometric {\em B} and {\em V} light curves of the semidetached eclipsing binary V Crt, using the Wilson-Devinney method, yielded photometric elements, including a photometric mass ratio of 0.40. Assuming the mass of the primary component to be 1.70 {\em M}_{sun}_ (F0 V), the absolute elements of V Crt are found to be m_c_=0.68 M_{sun}_, R_h_=1.77 {\em R}_{sun}_, R_c_=1.34 R_{sun}_, {\rf log}L_h_=0.87 L_{sun}_, {\rf log}L_c_=-0.06 L_{sun}_, M_bol,h_=2.52, M_bol,c_=4.84, {\rf log}g_h_=4.17, and {\rf log}g_c_=4.02. Since the secondary has already filled its Roche lobe and the primary is filling about 86% of its Roche lobe, it is suggested that in V Crt a reverse mass transfer may start in a short time. %I (1) Part of this work was carried out at the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Post Bag 4, Ganeshkhind, Pune 411 007, India. %R 1998PASP..110...98V %F ori/PASPv110n744 %J-104 %T The Luminosity Function of M30: Evidence for Rapidly Rotating Cores in the Cluster Giants?. %A VandenBerg Don A.,(1) %A Larson Ana M.,(2) %A De Propris Roberto (3) %I Department of Physics and Astronomy, University of Victoria, P. O. Box 3055, Victoria, BC, Canada V8W 3P6; (davb@uvvm.uvic.ca), (larson@uvastro.phys.uvic.ca), (propris@coma.jpl.nasa.gov) %B The observed luminosity function (LF) of M30 shows an excess in the number of red giants relative to the number of turnoff stars as compared with the predictions of canonical models. This well-known problem is reexamined in the light of new stellar evolutionary models that have been constructed using an improved equation of state formulation as well as recent opacities and nuclear reaction rates. Neither the improvements to the basic physics of stars nor the adoption of different choices, within reason, for the cluster distance (and hence age), chemical composition, or initial mass function have any appreciable effect on the LF discrepancy. However, it seems to be possible to reconcile theory with observation if the cluster stars retain significant amounts of angular momentum throughout their evolution. Stellar models, which treat rotation in the simple spherically symmetric approximation and which conserve angular momentum--leading to structures on the giant branch with rapidly rotating cores and slowly rotating envelopes--predict LFs in good agreement with that observed for M30. The amount of angular momentum that is required to achieve this consistency appears to be insufficient to have detectable consequences for the tightness of the observed color-magnitude diagram (though this needs to be checked using a two-dimensional code) or to affect predicted age versus turnoff-luminosity relations at more than the few percent level. %I (1) Killam Research Fellow. %I (2) Current address: Pierce College, 9401 Farwest Drive SW, Lakewood, WA 98498-1999. %I (3) Current address: MS 169-327, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109. %R 1998PASP..110..105F %F ori/PASPv110n744 %J-110 %T {\em VRI} Photometry of Stars in the Fields of 16 Blazars. %A Fiorucci Massimo %A Tosti Gino , %A Rizzi Nicola %I Cattedra di Astrofisica, Universit\`a di Perugia, via A. Pascoli, I-06123 Perugia, Italy; (tosti@pg.infn.it) %B We present a list of photometric {\em VRI} comparison sequences in the fields of 16 blazars. For six of these objects, comparison stars were calibrated for the first time during the present work. For most of the other 10 blazars, we improved the old sequences by either calibrating stars in the {\em R} and {\em I} bands or adding new comparison stars. Finding charts for 15 of these sequences are also reported. %K Galaxies: BL Lacertae Objects: General %R 1998PASP..110..111H %F ori/PASPv110n744 %J-124 %T Radio Maps of QSOs in Clusters. %A Hutchings J.B. %A Dewey A. %A Chaytor D., %A Ryneveld S. %I Dominion Astrophysical Observatory, National Research Council of Canada, 5071 West Saanich Road, Victoria, B.C., V8X 4M6, Canada; (john.hutchings@hia.nrc.ca) %A Gower A.C. %I Department of Physics and Astronomy, University of Victoria, P.O. Box 1700, Victoria, B.C., Canada; (agower@otter.phys.uvic.ca) %A Ellingson E. %I CASA, University of Colorado, Boulder, CO 80309-0389; (e.elling@wapiti.colorado.edu) %B We present 20 cm and 6 cm maps of 38 QSOs observed in the B configuration of the VLA. The maps are snapshots used in the discussion of the effects of cluster environment on radio properties of QSOs by Hutchings et al. We display maps of all QSOs from the sample of 43 that have significant structure. %R 1998PASP..110..125J %F ori/PASPv110n744 %J-151 %T 10^51^ Ergs: The Evolution of Shell Supernova Remnants. %A Jones, T.W. %A Rudnick, Lawrence %A Jun Byung-Il %I Department of Astronomy, University of Minnesota, Minneapolis, MN 55455 %A Borkowski Kazimierz J. %I Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 %A Dubner Gloria %I Instituto de Astronomia y Fisica del Espacio, Buenos Aires, Argentina %A Frail Dale A. %I National Radio Astronomy Observatory, Socorro, NM 87801 %A Kang Hyesung %I Department of Astronomy, University of Washington, Seattle, WA 98195-1580 %A Kassim Namir E. %I Naval Research Laboratory, Washington, DC 20375-5351 %A McCray Richard %I JILA, University of Colorado, Boulder, CO 80309-0440 %B This paper reports on the workshop ``10^51^ Ergs: The Evolution of Shell Supernova Remnants,'' hosted by the University of Minnesota, 1997 March 23-26. The workshop was designed to address fundamental dynamical issues associated with the evolution of shell supernova remnants and to understand better the relationships between supernova remnants and their environments. Although the title points only to classical, shell SNR structures, the workshop also considered dynamical issues involving X-ray-filled composite remnants and pulsar-driven shells, such as that in the Crab Nebula. Approximately 75 observers, theorists, and numerical simulators with wide-ranging interests attended the workshop. An even larger community helped through extensive on-line debates prior to the meeting to focus issues and galvanize discussion. In order to deflect thinking away from traditional patterns, the workshop was organized around chronological sessions for ``very young,'' ``young,'' ``mature,'' and ``old'' remnants, with the implicit recognition that these labels are often difficult to apply. Special sessions were devoted to related issues in plerions and ``thermal X-ray composites.'' Controversy and debate were encouraged. Each session also addressed some underlying, general physical themes: How are supernova remnant (SNR) dynamics and structures modified by the character of the circumstellar medium (CSM) and the interstellar medium (ISM), and vice versa? How are magnetic fields generated in SNRs and how do magnetic fields influence SNRs? Where and how are cosmic rays (electrons and ions) produced in SNRs, and how does their presence influence or reveal SNR dynamics? How does SNR blast energy partition into various components over time, and what controls conversion between components? In lieu of a proceedings volume, we present here a synopsis of the workshop in the form of brief summaries of the workshop sessions. The sharpest impressions from the workshop were the crucial and underappreciated roles that environments have on SNR appearance and dynamics and the critical need for broad-based studies to understand these beautiful but enigmatic objects. %K ISM: Cosmic Rays %K interstellar medium %K pulsars %K ISM: Supernova Remnants %R 1998PASP..110..152R %F ori/PASPv110n744 %J-164 %T Performance of the Canada-France-Hawaii Telescope Adaptive Optics Bonnette. %A Rigaut F.,(1) %A Salmon D. %A Arsenault R., %A Thomas J. %I Canada-France-Hawaii Telescope, 65-1238 Mamalahoa Highway, Kamuela, HI 96743; (rigaut@eso.org), (salmon@cfht.hawaii.edu), (arsenault@cfht.hawaii.edu), (thomas@cfht.hawaii.edu) %A Lai O. %A Rouan D.,(2) %A V\'eran J.P.,(2,)(3) %A Gigan P. %I Observatoire de Paris, Section de Meudon, 92190 Meudon principal Cedex, France; (lai@hplyot.obspm.fr), (daniel@isolde.obspm.fr), (veran@hplyot.obspm.fr), (pierre.gigan@obspm.fr) %A Crampton David ,(2) %A Fletcher J.M., %A Stilburn J. %I Dominion Astrophysical Observatory, HIA, NRC, Victoria, V8X 4M6, Canada; (david.crampton@hia.nrc.ca), (j.fletcher@hia.nrc.ca), (j.stillburn@hia.nrc.ca) %A Boyer C. %A Jagourel P. %I CILAS, route de Nozay, 91460 Marcoussis, France %B Extensive results from the commissioning phase of PUEO, the adaptive optics instrument adaptor for the Canada-France-Hawaii Telescope (CFHT), are presented and discussed. Analyses of more than 750 images recorded with a CCD and a near-IR camera on 16 nights in wavelengths from {\em B} to {\em H} are used to derive the properties of the compensated wavefront and images in a variety of conditions. The performance characteristics of the system are analyzed and presented in several ways, in terms of delivered Strehl ratios, full width half-maxima (FWHM), and quantities describing the improvements of both. A qualitative description is given of how the properties of the corrected images result from the structure function of the compensated phase. Under median seeing conditions, PUEO delivers essentially diffraction-limited images at {\em H} and {\em K} and images with FWHM ~ 0".1 at {\em J} and {\em I}, and provides significant gains down to {\em B}, with guide stars as faint as R=14. During good conditions, substantial gains were realized with guide stars as faint as R=17. A simple user interface and software that automatically and continuously optimizes the mode gains during observations makes the operational efficiency extremely high. A few astronomical examples are briefly discussed. %K adaptive optics %K high angular resolution %K seeing %K Telescopes %I (1) Current address: European Southern Observatory, Karl Schwarzschild Strasse 2, D-85748 Garching, Germany. %I (2) Visiting Astronomer, Canada-France-Hawaii Telescope, which is operated by the National Research Council of Canada, the Centre National de la Recherche Scientifique, and the University of Hawaii. %I (3) Also with the Ecole Sup\'erieure des T\'el\'ecommunications, 46, rue Barrault, F-75634 Paris Cedex 13, France. %R 1998PASP..110..165E %F ori/PASPv110n744 %J-185 %T Adaptive Optics Sky Coverage Calculations for the Gemini-North Telescope. %A Ellerbroek B.L. %I Starfire Optical Range, USAF Research Laboratory, Kirtland AFB, NM 87117; (ellerbrb@ug2.plk.af.mil) %A Tyler D.W. %I Schafer Corporation, Kirtland AFB, NM 87117; (tyler@freestyle.plk.af.mil) %B Sky coverage results are presented for several natural guide star (NGS) and laser guide star (LGS) adaptive optics (AO) configurations using scenario, telescope, and AO design parameters derived from the Gemini-North 8 m telescope. ``Sky coverage'' is defined as that fraction of the sky over which the AO system provides a useful level of performance, in this case a high Strehl ratio in the {\em J}, {\em H}, or {\em K} band. Some of the factors considered in this study include optimization of the AO wavefront reconstruction algorithm and control bandwidth, the effect of windshake-induced tip/tilt jitter, and the conjugation of the AO system's deformable mirror (DM) and wavefront sensor (WFS) to the dominant seeing layer at the Gemini-North site. The degree of compensation of the tip/tilt guide star image by the higher order adaptive optics is also considered. LGS AO using a single beacon in the mesospheric sodium layer typically improves sky coverage by about an order of magnitude relative to NGS AO, principally because a very dim natural guide star is sufficient for tip/tilt sensing when its image is sharpened by LGS higher order compensation. The values assumed for windshake, seeing, zenith angle, and the conjugate range of the DM and WFS also have a highly significant effect upon the estimated sky coverage for both the NGS and the LGS AO systems. The first three of these factors will need to be considered by scheduling algorithms for queue-based observing. %K adaptive optics %K Gemini Project %K laser guide stars %R 1998PASP..110..186H %F ori/PASPv110n744 %J-192 %T A Technique for Photometric Detection and Measurement of Unresolved Binary Systems. %A Hickson Paul %I Department of Physics and Astronomy, University of British Columbia, 2219 Main Mall, Vancouver, BC V6T 1Z4, Canada %B A technique is described for the detection and measurement of close binary systems whose images are unresolved. The method is based on analysis of the moment-of-inertia tensor of the image, from which the product of the binary flux ratio and square of the angular separation may be determined. Intrinsic asymmetries of the point-spread function are removed by comparison with the image of a reference star. Multiple exposures may be used to increase the signal-to-noise ratio without need of image alignment. An example is given of a simulated measurement of the dwarf carbon star system G77-61. %R 1998PASP..110..193S %F ori/PASPv110n744 %J-199 %T Automatic Noise Estimation from the Multiresolution Support. %A Starck Jean-Luc %I CEA/DSM/DAPNIA, SEI-SAP, F-91191 Gif-sur-Yvette Cedex, France; (jstarck@cea.fr) %A Murtagh Fionn %I Faculty of Informatics, University of Ulster, Londonderry BT48 7JL, Northern Ireland, UK; (fd.murtagh@ulst.ac.uk); and Observatoire Astronomique, 11, rue de l'Universit\'e, F-67000 Strasbourg, France; (fmurtagh@cdsxb6.u-strasbg.fr) %B We describe an automated approach for determining the noise associated with astronomical images. Detector noise is ever present and must be determined for high-quality image filtering or compression. We also show that the method can be used for very high quality cosmic-ray hit removal. Our method is based on a multiresolution transform of the image, the {\em \`a} {\em trous} wavelet transform. We present a range of examples and applications to illustrate the effectiveness of this approach. %R 1998PASP..110..200F %F ori/PASPv110n744 %J-209 %T A History of Infrared Extinction at CTIO, Chile, and a Possible Connection with the El Ni\~no Phenomenon. %A Frogel Jay A.(1) %I Department of Astronomy, The Ohio State University, 174 West 18th Avenue, Columbus, OH 43210; (frogel@galileo.mps.ohio-state.edu) %B Extinction coefficients and sensitivity values in the {\em JHKL} bandpasses measured on nearly 200 clear nights of observing between 1978 and 1992 on the 1.5 m and the Blanco 4 m telescopes at Cerro Tololo Inter-American Observatory are presented and discussed. Analysis of these data shows the following: there are seasonal variations in both the extinction coefficients and sensitivity values that are qualitatively consistent with expected variations in the amount of H_2_O in the atmosphere--relatively high in the summer months, lower in the winter months. The linear correlation coefficients between most of these quantities are statistically significant. The yearly mean values of these quantities also show significant variability of a few hundredths of a magnitude. The correlations between these yearly means are again consistent with variations in the H_2_O content of the atmosphere. At least some of these longer term variations are closely correlated with quantitative measures of the strength of the atmospheric and oceanic El Ni\~no/Southern Oscillation phenomenon. %I (1) The author was a staff astronomer at CTIO when most of these observations were made. CTIO is part of the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation. %R 1998PASP..110..210A %F ori/PASPv110n744 %J-213 %T Is the Astronomical Literature Still Expanding Exponentially?. %A Abt Helmut A. %I Kitt Peak National Observatory, National Optical Astronomy Observatories,(1) Box 26732, Tucson, AZ 85726-6732; (apj@noao.edu) %B Have the recent reductions in funding for astronomy resulted in a significant decrease in the exponential growth of our astronomical publications? I studied the growth of five American and European journals (A&A, AJ, ApJ, MNRAS, and PASP) that publish papers on a broad range of astronomical topics. For each, I counted the numbers of normalized pages and papers published at 10 intervals in 1960-1996. The average numbers of pages showed an exponential increase of 11% per year before the mid-1970s and 6% per year thereafter. The average number of papers increased exponentially by 9% before the mid-1970s and by 4% per year thereafter. The difference between these two sets of numbers is caused by an increase in average paper lengths from six normalized pages in 1960 to a constant 12 pages per paper during the last decade. Thus, the average paper lengths have asymptotically reached a constant value. However, there is no sign of a leveling off in the growth of our literature. The number of different authors also increased steadily. Over the past 36 years there have been few systematic shifts from one journal to another, implying that few authors have changed their habitual choices of journals. The numbers of papers in the three American journals has been directly proportional to the numbers of AAS members at 0.41 papers per year per member during the past 36 years. Therefore, the growth in our numbers of papers is entirely due to the growth in the numbers of astronomers, and the additional growth in pages is due to the growth in paper lengths. %I (1) Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. %R 1998PASP..110..214J %F ori/PASPv110n744 %J-214 %T Observational Study of AGB Stars in the Outer Galactic Disk. (DISSERTATION SUMMARY). %A Jiang Biwei %I Thesis work conducted at Department of Astronomical Science, School of Mathematical and Physical Science, The Graduate University for Advanced Studies, Japan and Nobeyama Radio Observatory, National Astronomical Observatory of JapanCurrent address: Beijing Astronomical Observatory, Chinese Academy of Sciences, Beijing 100080, P. R. China; (jiang@class1.bao.ac.cn)Ph.D. dissertation directed by: Shuji DeguchiPh.D. degree awarded: 1997