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J/ApJ/733/127           Four transits of WASP-4b          (Sanchis-Ojeda+, 2011)

Starspots and spin-orbit alignment in the WASP-4 exoplanetary system. Sanchis-Ojeda R., Winn J.N., Holman M.J., Carter J.A., Osip D.J., Fuentes C.I. <Astrophys. J., 733, 127 (2011)> =2011ApJ...733..127S
ADC_Keywords: Photometry ; Planets ; Stars, double and multiple Keywords: planetary systems - stars: rotation - stars: individual (WASP-4=USNO-B1.0 0479-0948995) Abstract: We present photometry of four transits of the exoplanet WASP-4b, each with a precision of approximately 500ppm and a time sampling of 40-60s. We have used the data to refine the estimates of the system parameters and ephemerides. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also found evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the starspot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be λ=-1+14-12degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. Future applications of this method using data from the CoRoT and Kepler missions will allow spin-orbit alignment to be probed for many other exoplanets. Description: We observed the transits of UT 2009 August 2, 6, and 10, and also 2009 September 26, with the Magellan (Baade) 6.5m telescope at Las Campanas Observatory in Chile. Objects: -------------------------------------------------------------------------- RA (2000) DE Designation(s) (Period) -------------------------------------------------------------------------- 23 34 15.06 -42 03 41.1 WASP-4 = 2MASS J23341508-4203411 (P=1.338231) -------------------------------------------------------------------------- File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table2.dat 36 2121 Photometry of WASP-4
See also: J/MNRAS/422/2024 : X-ray-age relation & exoplanet evaporation (Jackson+, 2012) J/A+A/539/A159 : WASP-4b transit griz light curves (Nikolov+, 2012) J/A+A/530/A5 : WASP-4b Ks detection of thermal emission (Caceres+, 2011) J/MNRAS/414/1278 : Eccentricities of transiting planets (Pont+, 2011) J/MNRAS/411/L46 : Exoplanet magnetic fields (Vidotto+, 2011) J/A+A/524/A25 : Radial Velocities on 6 exoplanet host stars (Triaud+, 2010) J/ApJ/716/1336 : Stability analysis of single-planet (Kopparapu+, 2010) J/MNRAS/399/287 : Transiting planetary system WASP-4 (Southworth+, 2009) J/AJ/137/3826 : Two transits of the giant planet WASP-4b (Winn+, 2009) Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 14 F14.6 d BJD Barycentric Julian Date (1) 16- 22 F7.5 --- RFlux Relative flux 24- 30 F7.5 --- e_RFlux Uncertainty in RFlux 32- 36 F5.3 --- Air Airmass
Note (1): The time-stamp represents the Barycentric Julian Date at midexposure, calculated based on the Julian Date with the code of Eastman et al. (2010PASP..122..935E).
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 16-Nov-2012
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

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