Gymnasieskolen imellem fag og sag - flerfaglighed i Almen studieforberedelse

Den nye gymnasiereform har i det seneste år betydet store forandringer på landets gymnasieskoler ogimplementering af helt nye forløb som eksempelvis “Almen studieforberedelse”. Artiklen tager udgangspunkt i udviklingsprojektet “Energi i Husholdningen” som beskæftiger sig med erfaringsopsamling irelation til flerfagligt samarbejde på baggrund af parallelle projektforløb i Almen studieforberedelsepå fire gymnasier. Samspillet mellem flere fag om en bestemt sag tages op til overvejelse med udgangspunkt i fokusgruppeinterviews med elever og lærere fra de fire gymnasier. Her behandles spørgsmål som “Hvordan er det flerfaglige samspil blevet realiseret?” og “Hvilke undervisningsformer befordrer det flerfaglige samarbejde?”. Der peges på iøjnefaldende problemstillinger som resultat af erfaringerne fra udviklingsprojektet. Herefter diskuteres forudsætninger for vellykkede flerfaglige forløb med særligt fokus på læreren i en vejlederrolle. Det konkluderes at hvis man ikke omlægger undervisningen i retning af den sag-orienterede undervisningsform, får det sag-orienterede samarbejde meget trange kår

Asteroseismology of the open clusters NGC 6791, NGC 6811, and NGC 6819 from nineteen months of Kepler photometry

We studied solar-like oscillations in 115 red giants in the three open clusters NGC 6791, NGC 6811, and NGC 6819, based on photometric data covering more than 19 months with NASA's Kepler space telescope. We present the asteroseismic diagrams of the asymptotic parameters \delta\nu_02, \delta\nu_01 and \epsilon, which show clear correlation with fundamental stellar parameters such as mass and radius. When the stellar populations from the clusters are compared, we see evidence for a difference in mass of the red giant branch stars, and possibly a difference in structure of the red clump stars, from our measurements of the small separations \delta\nu_02 and \delta\nu_01. Ensemble \'{e}chelle diagrams and upper limits to the linewidths of l = 0 modes as a function of \Delta\nu of the clusters NGC 6791 and NGC 6819 are also shown, together with the correlation between the l = 0 ridge width and the T_eff of the stars. Lastly, we distinguish between red giant branch and red clump stars through the measurement of the period spacing of mixed dipole modes in 53 stars among all the three clusters to verify the stellar classification from the color-magnitude diagram. These seismic results also allow us to identify a number of special cases, including evolved blue stragglers and binaries, as well as stars in late He-core burning phases, which can be potentially interesting targets for detailed theoretical modeling.Comment: 30 pages, 15 figures, 1 table, accepted to Ap

Asteroseismology of the Hyades red giant and planet host epsilon Tauri

Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-studied cluster such as the Hyades, the masses of the red giant stars are not well known, and previous mass estimates are based on model calculations (isochrones). The four known red giants in the Hyades are assumed to be clump (core-helium-burning) stars based on their positions in colour-magnitude diagrams, however asteroseismology offers an opportunity to test this assumption. Using asteroseismic techniques combined with other methods, we aim to derive physical parameters and the evolutionary stage for the planet hosting star epsilon Tau, which is one of the four red giants located in the Hyades. We analysed time-series data from both ground and space to perform the asteroseismic analysis. By combining high signal-to-noise (S/N) radial-velocity data from the ground-based SONG network with continuous space-based data from the revised Kepler mission K2, we derive and characterize 27 individual oscillation modes for epsilon Tau, along with global oscillation parameters such as the large frequency separation and the ratio between the amplitude of the oscillations measured in radial velocity and intensity as a function of frequency. The latter has been measured previously for only two stars, the Sun and Procyon. Combining the seismic analysis with interferometric and spectroscopic measurements, we derive physical parameters for epsilon Tau, and discuss its evolutionary status.Comment: 13 pages, 13 figures, 4 tables, accepted for publication in Astronomy & Astrophysic