Presentation is loading. Please wait.

Presentation is loading. Please wait.

Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?

Similar presentations


Presentation on theme: "Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?"— Presentation transcript:

1 Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?

2 Discovery space for indirect methods: Radial velocity Astrometry (r=distance to the star)

3 Mayor, M. & Queloz, D. 1995, Nature, 378, 355

4 Udry, S. et al. 2002, A&A, 390, 26

5 Jovian planets througout the 0.05-5 AU region. And…

6 No strong preference for orbital distances… …except for a “pile up” of hot Jupiters at P~3 days.

7 Planetary characteristics? Some trend in M versus R (bias?), but beyond 0.05-0.1 AU, little preference for low eccentricities: Butler, R.P. et al. 2006, ApJ, 646, 505

8 Eccentricities. II. Short Period Circularization

9 Even with incompleteness, strong preference for ~Jovian mass: Butler, R.P. et al. 2006, ApJ, 646, 505

10 Stars are different, turnover at low mass! “The brown dwarf desert”? Does this tell us that stars and planets form differently? Orion IMF

11 Is there an eccentricity preference w/mass? Not really… Marcy, G. et al. 2005, astro-ph/0505003

12 Is there an eccentricity preference w/mass? Not really, part II… Butler, R.P. et al. 2006, ApJ, 646, 505 ?

13 Another clue as to formation: Planet formation efficiency correlates strongly with metallicity! Fischer, D.A. & Valenti, J. 2005, ApJ, 622, 1102

14 What about planet formation efficiency & stellar mass? Johnson, J.A et al. 2007, ApJ, 665, 785 Radial velocity surveys mostly focused on Sun-like stars. Why? Active Chromospheres Low-contrast Lines

15 What about planet formation efficiency & stellar mass? Clever idea for higher mass A stars: Look at older systems that have evolved off the main sequence. Johnson, J.A et al. 2007, ApJ, 665, 785

16 What about planet formation efficiency & stellar mass? Two preliminary findings (that are being tested with larger surveys): 1. Planet formation efficiency increases w/mass. 2. The proportion of hot Jupiters decreases w/mass (not observational bias). M4 – K7 K5 – F8 F5 - A5

17 What about planetary multiplicity? Complex doppler patterns:

18 Summary of known multiple planetary systems: Marcy, G. et al. 2005, astro-ph/0505003

19 A super earth & GJ 876? Rivera, E.J. et al. 2005, (see class web site)

20 GJ 876 orbits evolve with time (expected w/mutual perturbations)! Are there others? OGLE-2005-BLG-390Lb (5.5 M ) MOA-2007-BLG-192Lb (3.3 M ) via micro-lensing. Gliese 581c (5 M, habitable zone) HD 181433 (7.5 M, P=3 yr) HD 40307 (4.2, 6.7, 9.4 M ) via radial velocity. Rivera, E.J. et al. 2005, (see class web site)

21 HD 168443 a: 7.2 Mj 58 days b: 17 Mj 1739 days =1/29.98 ?! 30:1?

22 HD 12661 a: 2.3 Mj 263 days a: 1.6 Mj 1444 days =1/5.5 11:2?

23 47 U Ma a: 2.5 Mj 1089 days b: 0.76 Mj 2594 days =1/2.4

24 Gleise 876 a: 1.89 Mj 61 days b: 0.56 Mj 30 days

25 HD 37124 a: 0.75 Mj 152 d b: 1.2 Mj 1495 d

26 ups And A: 0.69 Mj 4.6 d B: 1.9 Mj 241.5 d C: 3.75 Mj 1284 d

27 HD 82943 A: 1.63 Mj 444 d B: 0.88 222 d

28 55 Cnc A:.84 Mj 14.6 d B: 0.21 Mj 44.3 d C: 4 Mj 5360 d 3:1!

29 What we know: ~1% of solar-type stars have Hot Jupiters ~10% of solar-type stars have >M j planets with P<2000 days. Extrapolation of current incompleteness suggests ~17-19% w/planets @ <20 AU Multiple planetary systems are ~common Planetary resonances are ~common What can explain these properties? Improved R.V. surveys suggest an ~30% fraction of stars w/`hot Neptunes’ out to an AU (HARPS, arXiv:0806.4587v1) Planet fraction increases strongly with stellar metallicity and mass

30 Disk-star- and protoplanet interactions lead to migration while the gas is present. Core- accretion? Theory 1 AU at 140 pc subtends 0.’’007. Jupiter (5 AU): V_doppler = 13 m/s V_orbit = 13 km/s Simulation G. Bryden, JPL Thus, need to study objects in this phase…

31 Core-accretion models can now be compared to observations: Planets versus metallicity: Data Observed in open circles. Ida, S. & Lin, D. 2004, ApJ, 616, 567

32 Early disk models held that eccentricities were DAMPED. Not so fast… Goldreich & Sari 2005 Need an initial e~0.01. Goldreich, P. & Sari, R. 2003, ApJ, 585, 1024


Download ppt "Ge/Ay133 What have radial velocity surveys told us about (exo)-planetary science?"

Similar presentations


Ads by Google