1,081 research outputs found

    Interferometric Studies of Interstellar Calcium Lines

    Full text link
    Interferometric, photoelectric scans of the interstellar calcium K-lines in the spectra of 65 stars are presented. The scans were obtained with a PEPSIOS spectrometer having a passband with a full half-intensity width of 1.0 kms(-1) or 0.013A. The fivefold improvement in resolution over that used by Adams reveals numerous line components which correspond very well to those of the interstellar sodium lines, apart from frequent differences in relative intensities

    Voicing our concerns: Attempts at Decentring German Theatre and Performance Studies

    Get PDF
    The field of German Theatre and Performance Studies shows a lack of engagement with colonial history and questions of race. Its overwhelming whiteness manifests itself in a persistent ignorance of a decades-long tradition of works produced by women of colour, feminists, and Black, Indigenous and People of Colour (BIPOC) researchers and activists who have actively worked on decentring the discipline from a German-speaking context. This article, a critical conversation between four German theatre scholars, sets out to clarify what it means to decentre GTPS from a Western-centric focus and proposes some methodological solutions to achieve this goal. Through reflecting on our own educational experiences and the sharing of anecdotes from the classroom, we conclude that decentring means more than adding to the reading list, rather it entails a visceral, continuous unlearning of racist attitudes and methodologies and requires a careful positioning of teachers, students and researchers alike

    Photometry of the Chromospherically Active Binary HD 197010

    Full text link
    For the past several years we have been conducting a study of the spectroscopic and photometric characteristics of a sample X-ray emitting stars from the Einstein Observatory Medium Sensitivity Survey identified as probable binary systems by Fleming (1988) and Fleming, et al.(1989). One of these stars, HD 197010 ( = 1E2038.3-0046 = SAO 144692 = BD -1degree 4025) was discovered to be a short period eclipsing binary by Robb, et al.(1990). The ephemeris he presented was based on observations in 1989 and 1990, but only the 1990 observations included points at eclipse minimum. We report here on first results of almost a year of observations at Gettysburg College Observatory and the National Undergraduate Research Observatory, permitting a new determination of the photometric ephemeris of HD 197010

    SAO 23229: A New Double-Lined Spectroscopic Eclipsing Binary

    Full text link
    The discovery of eclipses of the bright star SAO 23229 (HD 14384; V=6.9; Spectral Type F5 V) by Indiana observer Dan Kaiser was described in a recent article in Sky and Telescope magazine (MacRobert, 1990). Photoelectric observations by H. Landis and D. Williams, reproduced in that article, show eclipses of 0.55 mag depth and period of 2.111 days. No secondary eclipses are reported, leaving open the question of whether the system contains a very dim secondary or whether it consists of two identical stars with an actual period of 4.2 days. We report here observations that favor the latter interpretation. [excerpt

    Fish Cohort Dynamics: Application of Complementary Modeling Approaches

    Get PDF
    The recruitment to the adult stock of a fish population is a function of both environmental conditions and the dynamics of juvenile fish cohorts. These dynamics can be quite complicated and involve the size structure of the cohort. Two types of models, i-state distribution models (e.g., partial differential equations) and i-state configuration models (computer simulation models following many individuals simultaneously), have been developed to study this type of question. However, these two model types have not to our knowledge previously been compared in detail. Analytical solutions are obtained for three partial differential equation models of early life-history fish cohorts. Equivalent individual-by-individual computer simulation models are also used. These two approaches can produce similar results, which suggests that one may be able to use the approaches interchangeably under many circumstances. Simple uncorrected stochasticity in daily growth is added to the individual-by-individual models, and it is shown that this produces no significant difference from purely deterministic situations. However, when the stochasticity was temporally correlated such that a fish growing faster than the mean 1 d has a tendency to grow faster than the mean the next day, there can be great differences in the outcomes of the simulations.This research was sponsored in part by the Electric Power Research Institute under contract no. RP2932-2 (DOE no. ERD-87-672) with the U.S. Department of Energy under contract no. DE-AC05-84OR21400 with Martin Marietta Energy Systems, and in part by grant no. NAI6RG0492-01 from the Coastal Ocean Program of the National Oceanic and Atmospheric Administration (NOAA) to the University of North Carolina Sea Grant College Program
    corecore