22 research outputs found

    Ledelse skal kunne ses, høres og føles

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    Samspillet mellem ledelsesret og medindflydelse skaber den fleksibilitet og dynamik, som er nødvendig i mødet med de udfordringer, som bla. globaliseringen stiller dansk erhvervsliv

    A Transiting Hot Jupiter Orbiting a Metal-Rich Star

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    We announce the discovery of Kepler-6b, a transiting hot Jupiter orbiting a star with unusually high metallicity, [Fe/H] = +0.34 +/- 0.04. The planet's mass is about 2/3 that of Jupiter, Mp = 0.67 Mj, and the radius is thirty percent larger than that of Jupiter, Rp = 1.32 Rj, resulting in a density of 0.35 g/cc, a fairly typical value for such a planet. The orbital period is P = 3.235 days. The host star is both more massive than the Sun, Mstar = 1.21 Msun, and larger than the Sun, Rstar = 1.39 Rsun.Comment: 12 pages, 2 figures, submitted to the Astrophysical Journal Letter

    Varmepumper og Lavtemperatur-fjernvarme - Rapportering fra to workshops

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    Denne rapport udgør et delbidrag af rapporteringen fra projektet ” Effektiv fjernvarme i fremtidens energisystem”, som under Energistyrelsens Energiforskningsprogram (EFP) udføres af et konsortium af EA-energianalyse, Systemanalyseafdelingen på Risø DTU, RAM-løse edb samt Fjernvarmens visionsudvalg nedsat under Dansk Fjernvarmeforening.Formålet med projektet er at belyse, hvordan fjernvarmens rolle i energiforsyningen kan udvikles på langt sigt gennem effektiv drift, anvendelse af ny teknologi samt dynamisk samspil med elmarkedet. En fremtidig udvikling mod et bæredygtigt energisystem vil kræve betydelige energibesparelser, herunder i rumopvarmningen. Dette vil alt andet lige mange steder føre til, at grundlaget for fjernvarmen vil ændre sig. Det er således centralt i projektet, at opstille en række scenarier for fjernvarmens fremtidige rolle i energisystemet, herunder at belyse hvad reducerede varmetab i fjernvarmenet og dynamisk anvendelse af kendte og nye energiteknologier kan betyde. Disse teknologier omfatter bl.a. varmepumper, geotermi, fjernkøling og varmelagring. Endvidere er formålet at belyse hvordan samspillet mellem elmarkedet og fjernvarmen kan effektiviseres, samt at pege på hvilke rammebetingelser der især er kritiske for fjernvarmens fortsatte udvikling og effektivisering.Som et led i analyserne i projektet er der afholdt to workshops om henholdsvis anvendelsen af varmepumper og lavtemperatur-fjernvarmenet. Denne rapport er en dokumentation af de to workshops, idet den indeholder program, deltagerliste, præsentationer og korte resumeer. I begge workshops deltog eksterne indledere parallelt med projektgruppens egne deltagere. Vi takker deltagerne for præsentationer og engageret deltagelse i diskussionerne

    Discovery and Rossiter-McLaughlin Effect of Exoplanet Kepler-8b

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    We report the discovery and the Rossiter-McLaughlin effect of Kepler-8b, a transiting planet identified by the NASA Kepler Mission. Kepler photometry and Keck-HIRES radial velocities yield the radius and mass of the planet around this F8IV subgiant host star. The planet has a radius RP = 1.419 RJ and a mass, MP = 0.60 MJ, yielding a density of 0.26 g cm^-3, among the lowest density planets known. The orbital period is P = 3.523 days and orbital semima jor axis is 0.0483+0.0006/-0.0012 AU. The star has a large rotational v sin i of 10.5 +/- 0.7 km s^-1 and is relatively faint (V = 13.89 mag), both properties deleterious to precise Doppler measurements. The velocities are indeed noisy, with scatter of 30 m s^-1, but exhibit a period and phase consistent with the planet implied by the photometry. We securely detect the Rossiter-McLaughlin effect, confirming the planet's existence and establishing its orbit as prograde. We measure an inclination between the projected planetary orbital axis and the projected stellar rotation axis of lambda = -26.9 +/- 4.6 deg, indicating a moderate inclination of the planetary orbit. Rossiter-McLaughlin measurements of a large sample of transiting planets from Kepler will provide a statistically robust measure of the true distribution of spin-orbit orientations for hot jupiters in general.Comment: 26 pages, 8 figures, 2 tables; In preparation for submission to the Astrophysical Journa

    Characteristics of Kepler Planetary Candidates Based on the First Data Set: The Majority are Found to be Neptune-Size and Smaller

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    In the spring of 2009, the Kepler Mission commenced high-precision photometry on nearly 156,000 stars to determine the frequency and characteristics of small exoplanets, conduct a guest observer program, and obtain asteroseismic data on a wide variety of stars. On 15 June 2010 the Kepler Mission released data from the first quarter of observations. At the time of this publication, 706 stars from this first data set have exoplanet candidates with sizes from as small as that of the Earth to larger than that of Jupiter. Here we give the identity and characteristics of 306 released stars with planetary candidates. Data for the remaining 400 stars with planetary candidates will be released in February 2011. Over half the candidates on the released list have radii less than half that of Jupiter. The released stars include five possible multi-planet systems. One of these has two Neptune-size (2.3 and 2.5 Earth-radius) candidates with near-resonant periods.Comment: Paper to accompany Kepler's June 15, 2010 data release; submitted to Astrophysical Journal Figures 1,2,& 3 revised. Improved labeling on all figures. Slight changes to planet frequencies in result

    Planetary Candidates Observed by Kepler, III: Analysis of the First 16 Months of Data

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    New transiting planet candidates are identified in sixteen months (May 2009 - September 2010) of data from the Kepler spacecraft. Nearly five thousand periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1,091 viable new planet candidates, bringing the total count up to over 2,300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multi-quarter photo-center offsets derived from difference image analysis which identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the new candidates. Ephemerides (transit epoch, T_0, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (Rp/R*), reduced semi-major axis (d/R*), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (197% for candidates smaller than 2Re compared to 52% for candidates larger than 2Re) and those at longer orbital periods (123% for candidates outside of 50-day orbits versus 85% for candidates inside of 50-day orbits). The gains are larger than expected from increasing the observing window from thirteen months (Quarter 1-- Quarter 5) to sixteen months (Quarter 1 -- Quarter 6). This demonstrates the benefit of continued development of pipeline analysis software. The fraction of all host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the Habitable Zone are forthcoming if, indeed, such planets are abundant.Comment: Submitted to ApJS. Machine-readable tables are available at http://kepler.nasa.gov, http://archive.stsci.edu/kepler/results.html, and the NASA Exoplanet Archiv
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