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Danish AsteroSeismology Centre – DASC astro.phys.au.dk/DASC

Danish AsteroSeismology Centre – DASC http://astro.phys.au.dk/DASC. Hans Kjeldsen Jørgen Christensen-Dalsgaard Søren Frandsen Frank Grundahl Torben Arentoft Pierre-Olivier Quirion Christoffer Karoff Danijela Jelicic. Asteroseismology with the Kepler mission.

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Danish AsteroSeismology Centre – DASC astro.phys.au.dk/DASC

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  1. Danish AsteroSeismology Centre – DASC http://astro.phys.au.dk/DASC Hans Kjeldsen Jørgen Christensen-Dalsgaard Søren Frandsen Frank Grundahl Torben Arentoft Pierre-Olivier Quirion Christoffer Karoff Danijela Jelicic Asteroseismology with the Kepler mission

  2. Institut for Fysik og Astronomi Aarhus Universitet Danish AsteroSeismology Centre SONG KASOC HELAS CoRoT KASC Kepler (NASA)

  3. Adiabatic sound speed

  4. UVES / VLT2

  5. Velocities fora Cen A using UVES/VLT2 Precision: 50-70 cm/s. Cadence 26 seconds!

  6. 27. december 2006

  7. Asteroseismology with Kepler

  8. USING PHOTOMETRYTO DETECT EARTH-SIZE PLANETS • The relative change in brightness (DL/L) is equal to the relative areas (Aplanet/Astar) • To measure 0.01% must get above the Earth’s atmosphere • Method is robust but you must be patience: Require at least 3 transits preferably 4 with same brightness change, duration and temporal separation Jupiter: 1% area of the Sun (1/100) Earth or Venus 0.01% area of the Sun (1/10,000)

  9. Kepler Mission is optimized for finding habitable planets ( 0.5 to 10 MÅ) in the HZ ( near 1 AU ) of solar-like stars • Continuously and simultaneously monitor 170,000 main-sequence stars • Use a one-meter Schmidt telescope: FOV >100 deg2 with an array of 42 CCD • Photometric precision: Noise < 20 ppm in 6.5 hours V = 12 solar-like star => 4s detection for Earth-size transit • Mission: Heliocentric orbit for continuous viewing > 4 year duration 12

  10. NASA Kepler mission – Launch date: 1. November 2008

  11. 512 targets: 1 min. 170,000 30 min. A region of the extended solar neighborhood in the Cygnus-Lyra regions along the Orion arm of our galaxy has been chosen. 14

  12. Goals of Kepler asteroseismology • to provide support for the studies of extrasolar planetary systems by characterizing the central stars of the systems, particularly radius • to identify giant stars in low-cadence observations, based on power spectra • to perform in-depth asteroseismic investigations of a large number of stars, predominantly but not exclusively those showing solar-like oscillations.

  13. Goals of Kepler asteroseismology • to provide support for understanding and correcting for the “noise” arising from stellar pulsations

  14. Organization of Kepler Asteroseismic Investigation (KAI) • Managed by a Steering Committee consisting of Ron Gilliland (chair), Jørgen Christensen-Dalsgaard, Tim Brown and Hans Kjeldsen • Based at Department of Physics and Astronomy, Aarhus (IFA) • Kepler Asteroseismic Science Operations Centre, KASOC (at IFA) • Kepler Asteroseismic Science Consortium, KASC

  15. Required activities • Selection of asteroseismic targets • Characterization of asteroseismic targets • Development and verification of data analysis pipeline • Development and verification of data interpretation pipeline • Developing stellar modelling techniques

  16. Kepler Asteroseismic Science Operations Center 2007 2008 2009 Kepler Launch Final KIC received: 180 days before launch Invitation the Asteroseismic community to join KASC First version of KASOC Pipe-line New target list for p-mode Targets: 30 days before uplink Selection of p-mode Targets for first 90d: 90 days before launch KASOC target list: #KIC and priority (rank) KASOC Review: Data analysis 120 days before launch 60 days before uplink Workshop: October 2007

  17. Kepler Asteroseismic Science Operations Center Kepler Archive at STSci / SOC (NASA) • Stellar Flux, Centroid, • background flux • Data with no transit information: • Extracted frequencies, amplitudes and phases • Power Spectrum • Time series with zero power at low frequencies HIGH-PASS FILTER KASOC, Aarhus in Denmark Asteroseismic frequency analysis Stellar Modelling Measurement of Stellar radius: Tested by use of the Aarhus p-mode Time Series Simulator Measured Stellar Properties

  18. Time series simulator and pipeline SW The Aarhus p-mode times series simulator ASTEC Asteroseismic time series simulator Stellar oscillations Oscillation frequencies Amplitude Mode lifetime Stellar convection Stellar activity L, M, Teff, damping Power spectrum Instrumental noise Granulation timescale Granulation amplitude Kepler Time series Rotation Size of spots Frequency separations Individual frequencies Instr. performance Stellar magnitude (V) Stellar density Core Helium content Detailed stellar properties

  19. Working Group Kepler Asteroseismic Science Consortium • Organize work, select a chair, divide responsibilities • Select KAI targets • Analyze data • Organize theoretical work • Publish results • Asteroseismology Target Selection Requirements • 60 targets: 4 years, 1-min. cadence • 160 targets: 1 year, 1-min. cadence • 1012 targets: 90 days, 1-min. cadence • > 50 targets: 4 years, 30-min. cadence • > 200 targets: 1 year, 30-min. cadence SPB stars delta Scuti stars

  20. Kepler asteroseismology

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