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Tautenburg planet search program

Tautenburg planet search program. Eike Guenther Artie Hatzes Davide Gandolfi Michael Hartmann Massimiliano Esposito (now Hamburger Sternwarte) Felice Cusano Michaela Döllinger (ESO). I. Planets of young stars. Eike Guenther Massimiliano Esposito.

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Tautenburg planet search program

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  1. Tautenburg planet search program Eike Guenther Artie Hatzes Davide Gandolfi Michael Hartmann Massimiliano Esposito (now Hamburger Sternwarte) Felice Cusano Michaela Döllinger (ESO)

  2. I. Planets of young stars Eike Guenther Massimiliano Esposito

  3. The orbits of exo-planets are as eccentric as those of binaries

  4. Many short-period planets... ..but is there a lack of very massive ones?

  5. Question: What fraction of close-in planets were destroyed in the first 10-100 Myr ? Close-in planets can be destroyed by: • Evaporation • Tidal interaction between the planet and the host star • Planet-planet interaction

  6. Weidenschilling & Marzari 1996 Nature 384, 19 Planet-planet interaction might play in important role in shaping planetary systems

  7. Planets of young stars • What is the frequency of massive, close-in planets? • Are the orbits eccentric or round? • Studying interaction of planets and disks

  8. Precise RV-measurements using the iodine cell

  9. Young stars are active and spots cause RV-variations

  10. How can we distinguish planets and activity? • Spots change in time: long time basis • Bisectors • CaH,K, and other chrosmospheric lines • photometry

  11. How active are the stars?

  12. Tautenburg Survey • Survey started Feb 6, 2001 • Age 30..300 Myr • 43 stars (some stars removed that were not young) • SpecTyp G,K,M • >2000 spectra

  13. Detection limits: a few examples σRV = 14.4 m/s Np = 48 σRV = 139 m/s Np = 68 10% 50% 100% 10% 100% 50% σRV = 11.3 m/s Np = 20 σRV = 10.5 m/s Np = 10

  14. TLS sample Lithium as age indicator

  15. HARPS survey • Age 10..100 Myr (TW Hydra, beta Pic, Horologium, Tucana, IC2391) • 85 stars • SpecTyp G,K,M • Ongoing since 2004

  16. A spin off: binaries for testing the evolutionary tracks with the VLTI

  17. THIS IS NOT A PLANET! K = 51.3 m/s ; e @ 0 ; MPsin(i) = 0.30 MJ ; a = 0.024 AU

  18. Planets (candidates) I

  19. Planets (candidates) II

  20. Be careful !!! Young stars are active, from the fact that all the data phases up one should not conclude that this is a planet! -- What we do now : photometry with REM -- Spectroscopy with CRIRES (RV caused by activity depends on wavelength)

  21. NAHUAL A high-resolution infrared spectrograph for planet hunting

  22. Results TLS survey: • 8 SBs • 0 planets • For 80% of the stars we can exclude M>2MJup and period>10 days. • For 95% of the stars we can exclude M>7MJup for periods < 10 days

  23. 35 stars Detection limits:results Percentage of stars without planets

  24. Results HARPS survey: • Sample: 85 stars (originally 92 but 7 are not young) • 5 SBs • Only one planet candidate! • Again: no massive (M>> 1 Mj), close-in planets!

  25. Conclusions • The frequency of close-in, massive planets of stars with an age of 10 to 300 Myr is about the same as that of old stars. --> At least not man very massive, close-in planets were destroyed in the age between 10 and 100 Myr. They were either destroyed at an earlier age, or never formed.

  26. Planets of giant stars(PhD thesis Michaela Döllinger) • Giant stars are cool and have a low vsini. • Problem I: giant stars have oscillations • Problem II: mass-determination

  27. Mass determination of giant stars(F Cusano, E.Guenther, A. Hatzes, CHARA Team) • First step: How good are the models from stellar atmospheres? • Compare true diameters derived with CHARA with those derived from spectroscopic observations Answer: TrueDiameter * (1.08+/-0.15)=SpecDiameter

  28. HD13189(mass of star: 3.5 Msun, msini of planet: 14 +/- 0.8 MJup)

  29. Pollux(mass of star. 1.7 Msun; msini of planet: 2.3 MJup)

  30. Results- massive stars of low metalicity can also have planets-the frequency of planets more massive than the sun could be as high as 25%

  31. III. Planets of F-stars:(1.1-1.7 Msun) • 30 Ari A binary • 30 Ari B has planet with orbital period of 327 days, and a mass of about 10 MJup

  32. IV. CoRoT • Convection, Rotation, Transits • CNES (France), ESA, Germany, Spain, Belgium, Austria, Brazil • Telescope: 27 cm aperture, inclined mirrors, 4.2m long, 270 kg. • Live time > 2.5 years • Optimized for ultra-high precision photometry • FOW 1.4x2.8 degrees • Observes fields continuously for 150 days

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