%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..493O %F ori/PASPv110n747 %J-532 %T The Compact Steep-Spectrum and Gigahertz Peaked-Spectrum Radio Sources. (Invited Review). %A O'Dea Christopher P. %I Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (odea@stsci.edu) %B I review the radio to X-ray properties of gigahertz peaked-spectrum (GPS) and compact steep-spectrum (CSS) sources, the current hypotheses for their origin, and their use to constrain the evolution of powerful radio galaxies. The GPS and CSS sources are compact, powerful radio sources with well-defined peaks in their radio spectra (near 1 GHz in the GPS and near 100 MHz in the CSS). The GPS sources are entirely contained within the extent of the narrow-line region ({<~}1 kpc), while the CSS sources are contained entirely within the host galaxy ({<~}15 kpc). The peaks in the spectra are probably due to synchrotron self-absorption, though free-free absorption through an inhomogeneous screen may also play a role. The turnover frequency varies with linear size {\em l} as {nu}_m_{prop.to}l^-0.65^, suggesting a simple physical relationship between these parameters. The radio morphologies are strikingly like those of the large-scale classical doubles, though some sources can have very distorted morphologies suggestive of interactions. Radio polarization tends to be low, and in some cases the Faraday rotation measures can be extremely large. The IR properties are consistent with stellar populations and active galactic nucleus (AGN) bolometric luminosity similar to that of the 3CR classical doubles. The optical host galaxy properties (absolute magnitude, Hubble diagram, evidence for interaction) are consistent with those of the 3CR classical doubles. CSS sources at all redshifts exhibit high surface brightness optical light (most likely emission-line gas) that is aligned with the radio axis. The optical emission-line properties suggest (1) interaction of the radio source with the emission-line gas and (2) the presence of dust toward the emission-line regions. X-ray observations of high-redshift GPS quasars and a couple of GPS galaxies suggest the presence of significant columns of gas toward the nuclei. Searches for cold gas in the host galaxies have revealed large amounts of molecular gas and smaller amounts of atomic gas in several sources, though probably not enough to confine the radio sources. The main competing models for the GPS and CSS sources are that (1) they are frustrated by interaction with dense gas in their environments and (2) they are young and evolving radio sources that will become large-scale sources. Combining the bright GPS and CSS samples with the 3CR results in a sample spanning a range in source size of 10^5^ that can be used to study source evolution. The number density versus linear size relation is consistent with a picture in which the sources expand with constant velocity and the radio power drops with linear size {\em l} according to P{prop.to}l^-0.5^. This strong evolution suggests that at least some of the GPS and CSS sources evolve to become lower luminosity FR 1 radio sources. The GPS and CSS sources are important probes of their host galaxies and will provide critical clues to the origin and evolution of powerful radio sources. %K Galaxies: Active %K Galaxies: Jets %K Galaxies: Quasars: General %R 1998PASP..110..533S %F ori/PASPv110n747 %J-552 %T Homogeneous Photometry for Star Clusters and Resolved Galaxies. I. A Survey of Bright Stars in the Fornax Dwarf Spheroidal Galaxy. %A Stetson Peter B.(1,)(2) %A Hesser James E.(1) %I National Research Council, Herzberg Institute of Astrophysics, Dominion Astrophysical Observatory, 5071 West Saanich Road, Victoria, British Columbia, V8X 4M6, Canada; (Peter.Stetson@hia.nrc.ca), (James.Hesser@hia.nrc.ca) %A Smecker-Hane Tammy A. %I Department of Physics and Astronomy, 4129 Physical Sciences 2, University of California, Irvine, CA 92697-4575; (smecker@carina.ps.uci.edu) %B We present accurate photometry on the Johnson {\em B}, Kron-Cousins {\em R} photometric system for approximately 100,000 stars in a (1)/(3) deg^2^ field centered on the dwarf spheroidal galaxy in Fornax. We identify numerous probable short-period variable stars, blue stars that appear to be the main sequence of a small population with an age of order 10^8^ yr, and two distinct types of luminous red star: an extended sequence of primarily carbon stars and a clump of mostly M giants slightly more luminous than the giant-branch tip. The spatial distribution of each of these subpopulations within the Fornax dwarf galaxy is considered. %K Galaxies: Individual: Name: Fornax Dwarf Galaxy %K Stars: Evolution %I (1) Visiting Astronomer, Cerro Tololo Inter-American Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. %I (2) Guest User, Canadian Astronomy Data Centre, which is operated by the Dominion Astrophysical Observatory for the Canadian National Research Council's Herzberg Institute of Astrophysics. %R 1998PASP..110..553R %F ori/PASPv110n747 %J-571 %T The Supernova Rate in Starburst Galaxies. %A Richmond Michael W. %I Department of Physics, Rochester Institute of Technology, Rochester, NY 14623-5603; (mwrsps@rit.edu) %A Filippenko Alexei V. %I Department of Astronomy, University of California, Berkeley, CA 94720-3411; (alex@astro.berkeley.edu) %A Galisky John %I 260 West Alamar Avenue 3, Santa Barbara, CA 93105-3756; (JohnG75259@aol.com) %B We conducted an optical CCD search for supernovae in a sample of 142 bright [mB{<=}16 mag], nearby (z{<=}0.03) starburst galaxies over the period 1988 December to 1991 June, to a limiting {\em R}-band magnitude of 18. Five supernovae were found, in all cases outside the host galaxy's nucleus. We determine supernova rates (in supernova units or SNU) in the extranuclear regions to be 0.7 {\em h}^2^ SNU for Type Ia, 0.7 {\em h}^2^ SNU for Type Ib/c, and ~0.6 {\em h}^2^ SNU for Type II, with large uncertainties but upper limits of 2.2 {\em h}^2^, 2.5 {\em h}^2^, and 1.7 {\em h}^2^ SNU, respectively. These rates are similar to those measured in ``normal'' galaxies. We found no evidence for a supernova-induced brightening in any galactic nucleus and, with a few reasonable assumptions, can place upper limits of 9 {\em h}^2^, 12 {\em h}^2^, and 7 {\em h}^2^ SNU on the rates of unobscured supernovae Types Ia, Ib/c, and II, respectively, inside the nuclei. %R 1998PASP..110..572P %F ori/PASPv110n747 %J-579 %T V380 Cygni Once More: A Close Detached Binary with an Evolved B-Type Component. I. Spectroscopic Orbits. %A Popper Daniel M. %I Division of Astronomy and Astrophysics, University of California, Los Angeles, CA 90095-1562; (popper@bonnie.astro.ucla.edu) %A Guinan Edward F. %I Department of Astronomy, Villanova University, Villanova, PA 19085; (guinan@ucis.vill.edu) %B New spectroscopic and photometric observations of V380 Cygni, a bright early B-type binary with an eccentric orbit and an evolved primary, B1.5 II-III, make possible a thorough study of this important, if not unique, system. In this first of two papers, the spectroscopic material is discussed. Values of the masses and provisional values of the radii are given, as is a spectroscopic estimate of the light ratio. The second paper will analyze the photometric material, including apsidal motion. The determination, with some degree of reliability, of the fundamental properties of an evolved early B-type star in the 10 solar mass range will enable its structure and evolutionary status to be compared with the predictions of models, including a sensitive test of convective-core overshooting. %R 1998PASP..110..580W %F ori/PASPv110n747 %J-585 %T Concerning the Reported Phase-modulated Changes in the Spectrum of 41 Sextantis. %A Worek Thaddeus F.(1) %I Department of Physics and Physical Sciences, Community College of Allegheny County, Pittsburgh, PA 15212; (tworek@ccac.edu) %B Sreedhar Rao et al. have reported that the metallic-line star 41 Sextantis exhibits significant changes in the depths and equivalent widths of its spectral lines and that these changes are coupled with the orbital motion of this spectroscopic binary. Based on their discovery, they suggest that 41 Sex is a possible evolutionary link between the Am and Ap stars. High-dispersion CCD spectra of 41 Sex, obtained in 1991 with the 0.9 m feed telescope and coud\'e spectrograph at the Kitt Peak National Observatory, were measured to determine the equivalent widths and depths of several metallic lines and the depths of Ca II K and H_8_ as a function of orbital phase. The spectrum changes that Sreedhar Rao et al. observed could not be verified with these data. Possible explanations for this lack of confirmation might be that the star was in a quiescent state in 1991 or that the reported changes to the spectrum happen on a timescale much greater than the orbital period. An updated solution for the spectroscopic orbital elements is also presented. %I (1) Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy Observatories, operated by the Association of Universities for Research in Astronomy, Inc., under contract with the National Science Foundation. %R 1998PASP..110..586L %F ori/PASPv110n747 %J-609 %T A Finding List of Faint UV-bright Stars in the Galactic Plane. IV. %A Lanning Howard H. %I Computer Sciences Corporation/Astronomy Programs, Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (lanning@stsci.edu) %A Meakes Michael %I Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218; (meakes@stsci.edu) %B One hundred fifty-five UV-bright stars have been identified on three two-color 48 inch (1.2 m) Oschin Schmidt plates as part of the continuing examination of Sandage survey plates centered on the Galactic plane. The three 6{deg}.6x6{deg}.6 field plates examined were centered at Galactic longitude ({\em l}) and latitude ({\em b}) coordinates of (123, -6), (141, 0), and (148, 0), respectively. The sources identified range in U-B color from near U-B~-0.1 to U-B~-1.2, and in magnitude from m_B_~10 to ~20. Some potentially interesting sources are discussed, and finding charts are provided for all UV sources listed. Correlations with previously identified objects in the literature are also provided. %R 1998PASP..110..610D %F ori/PASPv110n747 %J-633 %T Atmospheric Intensity Scintillation of Stars. III. Effects for Different Telescope Apertures. %A Dravins Dainis %A Lindegren Lennart , %A Mezey Eva %I Lund Observatory, Box 43, SE-22100 Lund, Sweden; (dainis@astro.lu.se), (lennart@astro.lu.se), (evam@astro.lu.se) %A Young Andrew T. %I Department of Astronomy, San Diego State University, San Diego, CA 92182-1221; (aty@mintaka.sdsu.edu) %B Stellar intensity scintillation in the optical was extensively studied at the astronomical observatory on La Palma (Canary Islands). Atmospheric turbulence causes ``flying shadows'' on the ground, and intensity fluctuations occur both because this pattern is carried by winds and is intrinsically changing. Temporal statistics and time changes were treated in Paper I, and the dependence on optical wavelength in Paper II. This paper discusses the structure of these flying shadows and analyzes the scintillation signals recorded in telescopes of different size and with different (secondary-mirror) obscurations. Using scintillation theory, a sequence of power spectra measured for smaller apertures is extrapolated up to very large (8 m) telescopes. Apodized apertures (with a gradual transmission falloff near the edges) are experimentally tested and modeled for suppressing the most rapid scintillation components. Double apertures determine the speed and direction of the flying shadows. Challenging photometry tasks (e.g., stellar microvariability) require methods for decreasing the scintillation ``noise.'' The true source intensity {\em I}({lambda}) may be segregated from the scintillation component {Delta}It,{lambda},x,y in postdetection computation, using physical modeling of the temporal, chromatic, and spatial properties of scintillation, rather than treating it as mere ``noise.'' Such a scheme ideally requires multicolor high-speed ({<~}10 ms) photometry on the flying shadows over the spatially resolved ({<~}10 cm) telescope entrance pupil. Adaptive correction in real time of the two-dimensional intensity excursions across the telescope pupil also appears feasible, but would probably not offer photometric precision. However, such ``second-order'' adaptive optics, correcting not only the wavefront phase but also scintillation effects, is required for other critical tasks such as the direct imaging of extrasolar planets with large ground-based telescopes. %R 1998PASP..110..634H %F ori/PASPv110n747 %J-634 %T A Submillimeter Imaging Survey of Ultracompact H II Regions. (Dissertation Summary). %A Hunter Todd R. %I Thesis work conducted at Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125Current address: Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-78, Cambridge, MA 02138; (thunter@cfa.harvard.edu)Ph.D. dissertation directed by T. G. Phillips; Ph.D. degree awarded 1997 %R 1998PASP..110..635F %F ori/PASPv110n747 %J-635 %T Fast X-Ray Oscillations: Probes of an Accreting Neutron Star. (Dissertation Summary). %A Ford Eric C. %I Thesis work conducted at Department of Physics, Columbia University, New York, NY 10027Current address: University of Amsterdam, Astronomical Institute, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands; (ecford@astro.uva.nl)Ph.D. dissertation directed by Philip Kaaret; Ph.D. degree awarded 1997 %R 1998PASP..110..636T %F ori/PASPv110n747 %J-636 %T Colliding Winds in Massive Binary Systems. (Dissertation Summary). %A Thaller Michelle %I Thesis work conducted at Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303Current address: IPAC, Caltech, Pasadena, CA 91125; (thaller@ipac.caltech.edu)Ph.D. dissertation directed by Douglas R. Gies; Ph.D. degree awarded 1998