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Radial Velocity Detection of Planets: II. Results

Radial Velocity Detection of Planets: II. Results. Mutiple Planets The Planet-Metallicity connection Fake Planets. Planetary Systems: 41 Multiple Systems. 41 Extrasolar Planetary Systems (18 shown). Star P (d) M J sini a (AU) e HD 82943 221 0.9 0.7 0.54

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Radial Velocity Detection of Planets: II. Results

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  1. Radial Velocity Detection of Planets:II. Results • Mutiple Planets • The Planet-Metallicity connection • Fake Planets

  2. Planetary Systems: 41 Multiple Systems

  3. 41 Extrasolar Planetary Systems (18 shown) Star P (d) MJsini a (AU) e HD 82943 221 0.9 0.7 0.54 444 1.6 1.2 0.41 GL 876 30 0.6 0.1 0.27 61 2.0 0.2 0.10 47 UMa 1095 2.4 2.1 0.06 2594 0.8 3.7 0.00 HD 37124 153 0.9 0.5 0.20 550 1.0 2.5 0.40 55 CnC 2.8 0.04 0.04 0.17 14.6 0.8 0.1 0.0 44.3 0.2 0.2 0.34 260 0.14 0.78 0.2 5300 4.3 6.0 0.16 Ups And 4.6 0.7 0.06 0.01 241.2 2.1 0.8 0.28 1266 4.6 2.5 0.27 HD 108874 395.4 1.36 1.05 0.07 1605.8 1.02 2.68 0.25 HD 128311 448.6 2.18 1.1 0.25 919 3.21 1.76 0.17 HD 217107 7.1 1.37 0.07 0.13 3150 2.1 4.3 0.55 Star P (d) MJsini a (AU) e HD 74156 51.6 1.5 0.3 0.65 2300 7.5 3.5 0.40 HD 169830 229 2.9 0.8 0.31 2102 4.0 3.6 0.33 HD 160691 9.5 0.04 0.09 0 637 1.7 1.5 0.31 2986 3.1 0.09 0.80 HD 12661 263 2.3 0.8 0.35 1444 1.6 2.6 0.20 HD 168443 58 7.6 0.3 0.53 1770 17.0 2.9 0.20 HD 38529 14.31 0.8 0.1 0.28 2207 12.8 3.7 0.33 HD 190360 17.1 0.06 0.13 0.01 2891 1.5 3.92 0.36 HD 202206 255.9 17.4 0.83 0.44 1383.4 2.4 2.55 0.27 HD 11964 37.8 0.11 0.23 0.15 1940 0.7 3.17 0.3

  4. The 5-planet System around 55 CnC 0.17MJ • 5.77 MJ • • 0.82MJ 0.11 MJ 0.03MJ Red: solar system planets

  5. The Planetary System around GJ 581 16 ME 7.2 ME 5.5 ME Inner planet 1.9 ME

  6. Can we find 4 planets in the RV data for GL 581? Note: for Fourier analysis we deal with frequencies (1/P) and not periods n1 = 0.317 cycles/d n2 = 0.186 n3 = 0.077 n4 = 0.015

  7. Almost: Published solution: The Period04 solution: P1 = 5.38 d, K = 12.7 m/s P2 = 12.99 d, K = 3.2 m/s P3 = 83.3 d, K = 2.7 m/s P4 = 3.15, K = 1.05 m/s P1 = 5.37 d, K = 12.5 m/s P2 = 12.93 d, K = 2.63 m/s P3 = 66.8 d, K = 2.7 m/s P4 = 3.15, K = 1.85 m/s s=1.17 m/s s=1.53 m/s Conclusions: 5.4 d and 12.9 d probably real, 66.8 d period is suspect, 3.15 d may be due to noise and needs confirmation. A better solution is obtained with 1.4 d instead of 3.15 d, but this is above the Nyquist frequency

  8. Measurements from two telescopes: AAT (red) and Keck (blue)

  9. s = 2.17 m/s

  10. The Planetary System around 61 Vir? Note: a 0.895 m/s offset was applied to the AAT data Published solution: The Period04 solution: P1 55.5 d, K = 1.2 m/s P2 = 3.8 d, K = 1.2 m/s P3 = 39 d, K = 1.14 m/s P1 = 4.214 d, K = 2.09 m/s P2 = 38.01 d, K = 3.58 m/s P3 = 124 d, K = 3.18 m/s s = 2.02 m/s s = 2.17 m/s With different periods and amplitudes (and the same number of sine functions) we have come up with a better solution.

  11. Problem #1 Largest peak is at 55 d, second peak is at 3.8 d, not 4.2 d. The False Alarm Probability of the 3.8 d peak is 0.004. I only believe planets with FAP << 0.001 Problem #2 Removing first two signals gives a peak at 39 d, but I do not believe it!

  12. AAT Data only Peak at 55 d (0.018 c/d), but nothing signficant at 4.2 d (0.24 c/d) Remove the strongest peak and get two signals at 0.033 c/d (30 d, moon contamination?) and another at 0.26 c/d (3.8 d), but smaller peak at 4.44 d

  13. Keck Data only Peak at 10.3 d (0.097c/d) Remove the dominant peak and residuals show a peak at 4.26 d (0.24 c/d)

  14. Keck AAT ?

  15. AAT Keck

  16. Conclusions about the „Planetary System“ around 61 Vir • Combined data shows a 3.8 d period, not 4.26 d • AAT data shows 3.8 d peak • Individual data sets do not show either 39 d, or 124 d signal There might be a signal at ~4 d, but the fact that different data sets give different answers makes me doubt this The other two „planets“ are noise → This is not a robust or confirmed planetary system because a different approach gives an entirely different answer!

  17. „The first principle is that you must not fool yourself – and you are the easiest person to fool.“ - Richard Feynman

  18. The CoRoT-7 Planetary System RV (m/s) JD Radial Velocity Measurements of CoRoT-7b with HARPS. CoRoT-7b is a transiting planet discovered by CoRoT. The additional planets were found from the radial velocity follow up. 44

  19. CoRoT-7c CoRoT-7b P = 3.7 Days Mass = 12.4 ME P = 0.85 Days Mass = 6.9 ME CoRoT-7d P = 9 Days Mass = 16.7 ME The RV variations are dominated by the stellar activity. This must be removed in order to find the planet(s) signal(s).

  20. 0.045 AU CoRoT-7d 0.017 AU CoRoT-7b CoRoT-7c 0.082 AU 47

  21. Resonant Systems Systems Star P (d) MJsini a (AU) e HD 82943 221 0.9 0.7 0.54 444 1.6 1.2 0.41 GL 876 30 0.6 0.1 0.27 61 2.0 0.2 0.10 55 CnC 14.6 0.8 0.1 0.0 44.3 0.2 0.2 0.34 HD 108874 395.4 1.36 1.05 0.07 1605.8 1.02 2.68 0.25 HD 128311 448.6 2.18 1.1 0.25 919 3.21 1.76 0.17 → 2:1 → 2:1 → 3:1 → 4:1 → 2:1 2:1 → Inner planet makes two orbits for every one of the outer planet

  22. Eccentricities • Period (days) Red points: Systems Blue points: single planets

  23. Mass versus Orbital Distance Eccentricities Red points: Systems Blue points: single planets Crazy idea: If you divide the disk mass among several planets, they each have a smaller mass

  24. The Dependence of Planet Formation on Stellar Mass

  25. Too faint (8m class tel.). Poor precision Ideal for 3m class tel. Main Sequence Stars RV Error (m/s) M0 K5 F0 K0 A5 G0 G5 A0 F5 Spectral Type ~10000 K ~3500 K 2 Msun 0.2 Msun

  26. Exoplanets around low mass stars • Ongoing programs: • ESO UVES program (Kürster et al.): 40 stars • HET Program (Endl & Cochran) : 100 stars • Keck Program (Marcy et al.): 200 stars • HARPS Program (Mayor et al.):~200 stars • Results: • Giant planets (2) around GJ 876. Giant planets around low mass M dwarfs seem rare • Hot neptunes around several. Currently too few planets around M dwarfs to make any real conclusions

  27. GL 876 System 1.9 MJ 0.6 MJ Inner planet 0.02 MJ

  28. Exoplanets around massive stars Difficult with the Doppler method because more massive stars have higher effective temperatures and thus few spectral lines. Plus they have high rotation rates. A way around this is to look for planets around giant stars. This will be covered in „Planets off the Main Sequence“ Result: few planets around early-type, more massive stars, and these are mostly around F-type stars (~ 1.4 solar masses)

  29. Galland et al. 2005 HD 33564 M* = 1.25 msini = 9.1 MJupiter P = 388 days e = 0.34 F6 V star

  30. A Planet around an F star from the Tautenburg Program HD 8673

  31. An F4 V star from the Tautenburg Program M* = 1.4 Mסּ P = 328 days Msini = 8.5 Mjupiter e = 0.24 Scargle Power Frequency (c/d)

  32. The Tautenburg F-star Planets As we will see later, more massive stars tend to have more massive planets.

  33. M ~ 1 Msun M ~ 1.4 Msun M ~ 0.2 Msun

  34. Preliminary conclusions: more massive stars have more massive planets with higher frequency. Less massive stars have less massive planets → planet formation is a sensitive function of the planet mass.

  35. Jovian Analogs: Giant Planets at ≈ 5 AU Definition: A Jupiter mass planet in a 11 year orbit (5.2 AU)

  36. One of the better candidates: Period = 14.5 yrs Mass = 4.3 MJupiter e = 0.16 Why care about Jupiter analogs?

  37. b Pic: A young star with planets e Eri: A young stars with a planet(s) There is a lot of junk in the solar system and in the past there was more.

  38. And sometimes this junk hits something. On Jupiter you get big holes. On the Earth it can destroy most of life.

  39. What would the Solar System Look Like without Jupiter? G. Wetherill asked this question and through numerical simulations establised: • The gravitational influence of Jupiter quickly removes most of the junk from the solar system. • Without Jupiter the frequency of a cataclysmic collision like the one that killed off the dynosaurs would occur every 100.000 years instead of every 150.000.000 Years Conclusion: Jupiters at 5 AU may be important for the development of intelligent life!

  40. A good Jovian analog but with a lot of junk, and in an eccentric orbit e Eri • Long period planet • Very young star • Has a dusty ring • Nearby (3.2 pcs) • Astrometry (1-2 mas) • Imaging (Dm =20-22 mag) • Other planets? Clumps in Ring can be modeled with a planet here (Liou & Zook 2000)

  41. Radial Velocity Measurements of e Eri Hatzes et al. 2000 Large scatter is because this is an active star. It has been argued that this is not a planet at all, but rather the signal due to activity.

  42. False alarm probability ~ 10–8 Scargle Periodogram of e Eri Radial velocity measurements Scargle Periodogram of Ca II measurements

  43. Period 6.85 Years Msini 1.55 MJupiter e 0.7 a 3.39 AU K 19 m/s

  44. The Best Candidates Note: These are the best candidates for direct imaging

  45. Wittenmyer et al. Combined data from 2 programs (McDonald and CFHT) to get a time base of over 23 years (probes to 8 AU). Could exclude M sin i > 2.0 ± 1.1 MJup for 17 objects (frequency < 6%)

  46. Astronomer‘s Metals More Metals ! Even more Metals !! Planets and the Properties of the Host Stars: The Star-Metallicity Connection

  47. The „Bracket“ [Fe/H] Take the abundance of heavy elements (Fe for instance) Ratio it to the solar value Take the logarithm e.g. [Fe/H] = –1 → 1/10 the iron abundance of the sun

  48. The Planet-Metallicity Connection? These are stars with metallicity [Fe/H] ~ +0.3 – +0.5 Valenti & Fischer There is believed to be a connection between metallicity and planet formation. Stars with higher metalicity tend to have a higher frequency of planets. This is often used as evidence in favor of the core accretion theory There are several problems with this hypothesis

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