208 research outputs found

    Ingress observations of the 1980 eclipse of the symbiotic star CI Cyngni

    Get PDF
    One of the major results from the IUE may prove to be the knowledge gained by studies of the ultraviolet spectra of symbiotic stars. Symbiotics combine spectral features of a cool M giant like photosphere with strong high excitation emission lines of nebular origin, superposed. The UV spectra are dominated by intense permitted and semiforbidden emission lines and weak continua indicative of hot compact objects and accretion disks. Two symbiotics, AR Pav and CI Cyg are thought to be eclipsing binaries and IUE observations during the 1980 eclipse of CI Cygni are discussed

    UV chromospheric and circumstellar diagnostic features among F supergiant stars

    Get PDF
    A survey of F supergiant stars to evaluate the extension of chromospheric and circumstellar characteristics commonly observed in the slightly cooler G, K, and M supergiant is discussed. An ultraviolet survey was elected since UV features of Mg II and Fe II might persist in revealing outer atmosphere phenomena even among F supergiants. The encompassed spectral types F0 to G0, and luminosity classes Ib, Ia, and Ia-0. In addition, the usefulness of the emission line width-to-luminosity correlation for the G-M stars in both the Ca II and Mg II lines is examined

    2D Monte-Carlo Radiative transfer modeling of the disk shaped secondary of Epsilon Aurigae

    Full text link
    We present two dimensional Monte-Carlo radiative transfer models for the disk of the eclipsing binary ϵ\epsilon Aur by fitting its spectral energy distribution from optical to the far-IR wavelengths. We also report new observations of ϵ\epsilon Aur made by AKARI in its five mid and far-IR photometric bands and were used to construct our SED. The disk is optically thick and has flared disk geometry containing gas and dust with a gas to dust mass ratio of 100. We have taken the primary of the binary to be a F0Iae-type post-AGB star and the disk is heated by a B5V hot star with a temperature of 15,000 K at the center of the disk. We take the radius of the disk to be 3.8 AU for our models as constrained from the IR interferometric imaging observations of the eclipsing disk. Our models imply that the disk contains grains which are much bigger than the ISM grains (grain sizes 10μ\mu to 100μ\mu). The grain chemistry of the disk is carbonaceous and our models show that silicate and ISM dust chemistry do not reproduce the slope of the observed SED in the mid-IR to far-IR regions. This implies that the formation of the disk shaped secondary in ϵ\epsilon Aur system could be the result of accretion of matter and or mass transfer from the primary which is now a F0Iae post-AGB star. It is not a proto-planetary disk. The disk is seen nearly edge on with an inclination angle larger than 85o^{o}. We propose from our radiative transfer modeling that the disk is not solid and have a void of 2AU radius at the center within which no grains are present making the region nearly transparent. The disk is not massive, its mass is derived to be less than 0.005M⊙_{\odot}.Comment: 27 pages, 5 figures, 2 table

    Process for Removing Sulfur and Producing Enhanced Quality and Environmentally Acceptable Products for Energy Production from Coal

    Get PDF
    A process for producing enhanced quality adsorbent carbons and environmentally acceptable materials for energy production from coal includes an initial step of physically cleaning the coal to remove organic sulfur and mineral tailings. Next, a coal slurry of feedstock and water is prepared. Phosphoric acid is then mixed into the water of the coal slurry to provide by volume 15-85% and more preferably 50-85% phosphoric acid. The slurry is then heated and held in a temperature range between 85° and 230° C. for a period of at least five minutes to allow the phosphoric acid to penetrate deeply into the coal. Then the coal slurry is carbonized at a temperature of between 200°-700° C. for at least five to sixty minutes. The processing produces unique products including a low ash content, low sulfur content carbon solid, a tar with a sulfur content of less than 0.05% of the original feedstock and a gas product having a hydrogen to methane ratio of at least 4:1

    Particle Separation/Purification System, Diffuser and Related Methods

    Get PDF
    A separator and related separation methods are for intended use in separating particles having a selected charge from a particle mixture entrained in or carried by a fluid flow. The separator comprises a tubular, elongated body for receiving the fluid flow. At least one and preferably a pair of electrodes may be provided to create an electric field in at least a portion of the body through which the fluid flow passes, and at least one partition defines first and second channels for receiving the flow downstream of the portion of the body including the electric field. In one embodiment, the electrode is oriented such that a direction of gravity acting on particles having a selected charge passing through the electric field directs the selectively charged particles towards the first or second electrode. A system may incorporate the separator, along with a diffuser

    Particle Separation/Purification System, Diffuser and Related Methods

    Get PDF
    A separator for intended use in separating particles having a selected charge from a particle mixture entrained in or carried by a fluid flow is disclosed. The separator comprises a tubular, elongated body for receiving the fluid flow. At least one and preferably a pair of electrodes may be provided to create an electric field in at least a portion of the body through which the fluid flow passes, and at least one partition defines first and second channels for receiving the flow downstream of the portion of the body including the electric field. In one embodiment, the electrode is oriented such that a direction of an electrical field force acting on particles having a selected charge passing through the electric field is not perpendicular to a direction of gravity. A system incorporating the separator is disclosed, along with a diffuser and related methods

    Ultraviolet and X-ray detection of the 56 Peg system (KO 2p + WD)

    Get PDF
    Both IUE short and long wavelength exposures of the 56 Peg system are discussed. This mild barium star has an X-ray luminosity of 3 x 10 to the 31st power ergs/1, comparable to the rapidly rotating RS CVn binary systems, yet lies in a region of the HR diagram where stellar X-rays are generally not observed. This cool, bright giant is not a rapid rotator and the key to understanding its emission lies in the recent discovery of its white dwarf companion. Accretion onto the white dwarf of approximately 0.1% of the stellar wind of the primary is sufficient to power an X-ray source of the observed luminosity. Reprocessing of the X-rays in the cool dense stellar wind explains the origin of the UV emission line spectrum, and may explain the time varying asymmetry of the Mg 2 kappa line profile that is observed. Graphs which show observed fluxes and wavelengths are discussed

    Method and Apparatus for Triboelectric-Centrifugal Separation

    Get PDF
    A method for separating two species of particles present in raw feedstock includes electrically charging at least one of the species of particles being separated. Next is the subjecting of the particles to both centrifugal and electrostatic forces. This is done in a manner so as to provide an additive effect and thereby achieve enhanced separation of the two particle species. An apparatus for processing the raw feedstock in accordance with the method is also disclosed

    Multi-wavelength observations of the peculiar red giant HR 3126

    Get PDF
    Ultraviolet observations of the red giant HR 3126 are combined with multi-wavelength data in order to provide a firmer basis for explaining the arc-minute sized nebula surrounding the object. Possibilities as to the location of HR 3126 on the Hertzsprung-Russel diagram, and to the formation mechanisms of the reflection nebula IC 2220 associated with it, are summarized
    • …
    corecore