Access to Astronomical Catalogues

← Click to display the menu
J/A+A/524/A25    Radial Velocities on 6 exoplanet host stars     (Triaud+, 2010)

Spin-Orbit angle measurements for six southern transiting planets; New insights into the dynamical origins of hot Jupiters. Triaud A.H.M.J., Collier C.A., Queloz D., Anderson D.R., Gillon M., Hebb L., Hellier C., Loeillet B., Maxted P.F., Mayor M., Pepe F., Pollacco D., Segransan D., Smalley B., Udry S., West R.G., Wheatley P.J. <Astron. Astrophys. 524, A25 (2010)> =2010A&A...524A..25T
ADC_Keywords: Planets ; Radial velocities Keywords: binaries: eclipsing - stars: general - techniques: spectroscopic Abstract: For transiting planets, the Rossiter-McLaughlin effect allows the measurement of the sky-projected angle beta between the stellar rotation axis and a planet's orbital axis. Using the HARPS spectrograph, we observed the Rossiter-McLaughlin effect for six transiting hot Jupiters found by the WASP consortium. We combine these with long term radial velocity measurements obtained with CORALIE. We found that three of our targets have a projected spin-orbit angle above 90 degrees: WASP-2b: beta=153+11-15°, WASP-15b: beta=139.6+5.2-4.3° and WASP-17b: beta=148.5+5.1-4.2° ; the other three (WASP-4b, WASP-5b and WASP-18b) have angles compatible with 0 degrees. There is no dependence between the misaligned angle and planet mass nor with any other planetary parameter. All orbits are close to circular, with only one firm detection of eccentricity on WASP-18b with e=0.00848+0.00085-0.00095. No long term radial acceleration was detected for any of the targets. Combining all previous 20 measurements of beta and our six, we attempt to statistically determine the distribution of the real spin-orbit angle psi and find that between about 45 and 85% of hot Jupiters have psi>30°. Observations and predictions using the Kozai mechanism match well. If these observational facts are confirmed in the future, we may then conclude that most hot Jupiters are formed from a dynamical and tidal origin without the necessity to use type I or II migration. At present, standard disc migration cannot explain the observations without invoking at least another additional process. Description: Radial velocities from 6 exoplanet host stars. The velocities are extracted from the CORALIE and HARPS spectrographs by means of a cross-correlation and the subsequent fit of a Gaussian on the resulting mean absorption line. Objects: ---------------------------------------------------------- RA (2000) DE Designation(s) ---------------------------------------------------------- 20 30 54.1 +06 25 46 WASP-2b = WASP-2b 23 34 15.0 -42 03 41 WASP-4b = WASP-4b 23 57 23.8 -41 16 38 WASP-5b = WASP-5b 13 55 42.7 -32 09 35 WASP-15b = WASP-15b 15 59 50.9 -28 03 42 WASP-17b = WASP-17b 01 37 25.0 -45 40 40 WASP-18b = HD 10069b ---------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file planets.dat 33 6 Orbital parameters (from table3) rvdata.dat 56 442 *The Radial-Velocity data extracted by fitting a Gaussian function on a Cross-Correlation Function resulting from comparing the spectra with a mask corresponding to its spectral type
Note on rvdata.dat: The data is presented per instrument and separated in various datasets: overall Doppler shift and Rossiter-McLaughlin effect, as was done for the fits. Within each dataset, it is presented chronologically.
See also: J/A+A/508/1509 : Sky maps for hot Jupiters (Heller+, 2009) J/A+A/513/L8 : BD+20 1790 radial velocity curve (Figueira+, 2010) Byte-by-byte Description of file: planets.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Planet name 10- 18 F9.7 d P Orbital period 21- 26 F6.4 AU a Semi-major axis of orbit 28- 33 F6.3 jovMass Mp Mass of planet, in Jovian masses
Byte-by-byte Description of file: rvdata.dat
Bytes Format Units Label Explanations
1- 8 A8 --- Name Planet name 10- 11 A2 --- Inst Instrument used (1) 13- 26 F14.6 d BJD Calculated Barycentric Julian Date at mid exposure (weighted in time according to flux) 30- 38 F9.5 km/s RV Estimated Radial Velocity of the star at Solar system barycentre 42- 48 F7.5 km/s e_RV Estimated 1 sigma error bar on RV 53- 56 I4 s Exp Time of exposure
Note (1): Instruments as follows: S1 = SOPHIE, orbital Doppler shift C1 = CORALIE, orbital Doppler shift C2 = CORALIE, Rossiter-McLaughlin effect H1 = HARPS, orbital Doppler shift H2 = HARPS, Rossiter-McLaughlin effect
Acknowledgements: Amaury Triaud (Obs. de Geneve), Amaury.Triaud(at)unige.ch
(End) Patricia Vannier [CDS] 16-Aug-2010
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

catalogue service

© UDS/CNRS

Contact