Department of Astrophysics, Center of Astrobiology (CAB/INTA-CSIC) and Department de Theoretical Physics, Universidad Aut´onoma de Madrid (UAM) Characterization of the planet-host stars WTS-1 and WTS-2, and detection of the secondary eclipses of WASP-10b and Qatar-1b Submitted by Patricia Cruz Gamba to the Universidad Aut´onoma de Madrid, to obtain the Degree of Doctor in Astrophysics Supervisor: Dr. David Barrado y Navascu´es (Department of Astrophysics, Center of Astrobiology - CAB/INTA-CSIC) Tutor: Dr. Carlos Eiroa de San Francisco (Department de Theoretical Physics, Universidad Aut´onoma de Madrid - UAM) Madrid, 2015 Departamento de Astrof´ısica, Centro de Astrobiolog´ıa(CAB/INTA-CSIC) y Departamento de F´ısica Te´orica, Universidad Aut´onoma de Madrid (UAM) Caracterizaci´on de las estrellas con planetas WTS-1 y WTS-2 y detecci´on de los eclipses secundarios de WASP-10b y Qatar-1b Memoria presentada por Patricia Cruz Gamba para optar al grado de Doctora en Astrof´ısica por la Universidad Aut´onoma de Madrid Director: Dr. David Barrado y Navascu´es (Departamento de Astrof´ısica, Centro de Astrobiolog´ıa- CAB/INTA-CSIC) Tutor: Dr. Carlos Eiroa de San Francisco (Departmento de F´ısica Te´orica, Universidad Aut´onoma de Madrid - UAM) Madrid, 2015 David Barrado y Navascu´es, Doctor en Ciencias F´ısicas y Cient´ıfico titular del Centro de Astrobiolog´ıa (CAB/INTA-CSIC) y Carlos Eiroa de San Francisco, Doctor en Ciencias F´ısicas y Profesor Titular de la Universidad Aut´onoma de Madrid (UAM) CERTIFICAN que la presente memoria Caracterizaci´on de las estrellas con planetas WTS-1 y WTS-2 y detecci´on de los eclipses secundarios de WASP-10b y Qatar-1b ha sido realizada por Patricia Cruz Gamba bajo nuestra direcci´on y tutela respectivamente. Consideramos que esta memoria contiene aportaciones suficientes para constituir la Tesis Doctoral del interesado. En Madrid, a 28 de Mayo de 2015 David Barrado y Navascu´es Carlos Eiroa de San Francisco A mi hijo, Arthur, luz de mi vida, y a mi marido, Sergio, mi puerto seguro. Contents Contents i List of Figures iii List of Tables v Agradecimientos vii 1 Introducci´on 1 1.1 Escenariodelosexoplanetas. ..... 2 1.2 Detecci´on de luz planetaria . ..... 5 1.3 WTS:WFCAMTransitSurvey . 9 1.4 The CASE study: the Calar Alto Secondary Eclipse study . ......... 10 1.5 Elobjetivodelatesis ............................. 11 2 Introduction 15 2.1 Exoplanetsscenario .............................. 16 2.2 Detection of planetary light . ..... 19 2.3 WTS:theWFCAMTransitSurvey. 22 2.4 The CASE study: the Calar Alto Secondary Eclipse study . ......... 23 2.5 Outlookofthisthesis ............................. 25 3 The characterization of two planet-host stars detected in the WFCAM Transit Survey 27 3.1 TheWFCAMTransitSurvey . 28 3.1.1 UKIRT/WFCAM J-band photometry and the transit detection algorithm 28 3.2 WTS-1........................................ 30 3.2.1 Follow-up observations of WTS-1 . 30 3.2.2 Analysisandresults . .. .. .. .. .. .. .. .. 33 3.3 WTS-2........................................ 38 3.3.1 Follow-up observations of WTS-2 . 38 3.3.2 Analysisandresults . .. .. .. .. .. .. .. .. 42 3.4 TheexoplanetsWTS-1bandWTS-2b . 45 3.5 Conclusions ..................................... 46 4 Detection of the secondary eclipse of WASP-10b in the Ks-band 47 4.1 Introduction.................................... 48 4.2 Observationsanddatareduction . ..... 49 4.3 Analysis....................................... 51 i ii Contents 4.3.1 Correction of systematic effects . 51 4.3.2 Modeling the secondary eclipse . 54 4.4 Discussion...................................... 60 4.4.1 A circular orbit for WASP-10b . 60 4.4.2 WASP-10b’s thermal emission . 60 4.5 Conclusions ..................................... 63 5 A detection of the secondary eclipse of Qatar-1b in the Ks-band 65 5.1 Introduction.................................... 66 5.2 Observationsanddatareduction . ..... 67 5.3 Dataanalysisandresults . 68 5.3.1 Correction of systematic effects . 70 5.3.2 Amodelforthesecondaryeclipse . 72 5.4 Discussion...................................... 76 5.4.1 Derived orbital configuration . 76 5.4.2 ThermalemissionofQatar-1b. 78 5.5 Conclusions ..................................... 79 6 Final discussion: our results in context 81 6.1 Transiting exoplanets scenario . ....... 81 6.2 TheWFCAMTransitSurvey: WTS-1andWTS-2 . 86 6.2.1 Comparison of general properties . 86 6.2.2 Secondaryeclipses ............................. 89 6.3 TheCASEstudy: WASP-10bandQatar-1b . 90 6.3.1 Secondary eclipses in the Ks-band . 90 6.3.2 Presence or absence of thermal inversions . ...... 94 7 Conclusions 99 8 Discusi´on final: nuestros resultados en contexto 103 8.1 Escenario de los exoplanetas que transitan . ......... 103 8.2 ElWFCAMTransitSurvey: WTS-1yWTS-2 . 109 8.2.1 Comparaci´on de las propiedades generales . ....... 109 8.2.2 Eclipsessecundarios . 112 8.3 ElCASEstudy: WASP-10byQatar-1b . 113 8.3.1 EclipsessecundariosenlabandaKs . 113 8.3.2 Presencia o ausencia de inversi´on t´ermica . ........ 116 9 Conclusiones 121 10 Future work 125 Published papers 129 Bibliography 133 List of Figures 1.1 Velocidadradialde51Peg. ... 3 1.2 CurvadeluzplegadadeHD209458. ... 4 1.3 Par´ametros obtenidos de la curva de luz de un planeta en tr´ansito. 4 1.4 Ilustraci´on de la luz observada de un exoplaneta. ........... 5 1.5 EclipsesecundariodeTrES-1b. ..... 6 1.6 EclipsesecundariodeTrES-3b. ..... 7 1.7 EclipsesecundariodeTrES-2b. ..... 8 1.8 Magnitud de la estrella en la banda K versus el cociente de los radios del planetaydelaestrella. .............................. 11 2.1 Radialvelocityof51Peg. 17 2.2 Folded light curve of HD 209458. 18 2.3 Parameters obtained from the light curve of a transiting planet. 18 2.4 Illustration of the observed light of an exoplanet. ............ 19 2.5 SecondaryeclipseofTrES-1b. ..... 20 2.6 SecondaryeclipseofTrES-3b. ..... 21 2.7 SecondaryeclipseofTrES-2b. ..... 22 2.8 Stellar K-band magnitude versus planet-star radii ratio. ............ 24 3.1 SEDfittingforWTS-1. .............................. 33 3.2 The TWIN WTS-1 spectrum in comparison with synthetic spectra. 35 3.3 The ISIS WTS-1 spectrum of the Hα line in comparison with synthetic spectra. 36 3.4 SEDfittingforWTS-2. .............................. 40 3.5 Stacked spectrum of WTS-2 using eight of the TWIN observations. 41 3.6 The TWIN stacked WTS-2 spectrum in comparison with synthetic spectra. 43 3.7 Modified Hertzsprung-Russell diagram for WTS-2. ......... 44 4.1 Differential light curve of WASP-10 in the Ks-band. ........ 52 4.2 RMS of the residuals of WASP-10’s light curve. ........ 53 4.3 Secondary eclipse of WASP-10b in the Ks-band. ........ 55 4.4 Distributions from the MCMC analysis of WASP-10’s light curve. 56 4.5 The MCMC analyses for different bin sizes of the WASP-10’s light curve. 58 4.6 Secondary eclipse of WASP-10b in the Ks-band from the joint-MCMC analysis. 59 4.7 Different orbital configurations for WASP-10b. ........ 59 4.8 Model spectrum of thermal emission of WASP-10b. ........ 61 5.1 Differential light curve of Qatar-1 in the Ks-band. ......... 69 5.2 RMS of the residuals of Qatar-1’s light curve. ......... 71 iii iv List of Figures 5.3 Secondary eclipse of Qatar-1b in the Ks-band. ......... 73 5.4 Distributions from the MCMC analysis of Qatar-1’s light curve......... 74 5.5 The MCMC analyses for different bin sizes of the Qatar-1’s light curve. 75 5.6 Secondary eclipse of Qatar-1b in the Ks-band from the joint-MCMC analysis. 76 5.7 Different orbital configurations for Qatar-1b. ......... 77 5.8 Model spectrum of thermal emission of Qatar-1b. ......... 78 6.1 Mass–Radius diagram of known transiting planets. .......... 82 6.2 Mass–Radius diagram of host stars with transiting planets. .......... 84 6.3 Orbital semimajor axis versus planetary density of transiting planets. 86 6.4 Planetary radii as a function of time. ....... 87 6.5 Planetary radius as a function of orbital semimajor axis............. 89 6.6 Stellar 2MASS K-band magnitude versus observed Ks-band secondary eclipse depth. ........................................ 91 6.7 Planetary radius versus incident radiation. ........... 91 6.8 Incident radiation against observed Ks-band brightness temperature. 94 ′ 6.9 The log(RHK) activity index as function of the Ks-band brightness temperature. 96 8.1 Diagrama masa–radio de los exoplanetas conocidos que transitan. 104 8.2 Diagrama masa–radio de estrella centrales con planetas que transitan. 106 8.3 Semieje mayor orbital frente a la densidad planetaria de los planetas que tran- sitan.......................................... 108 8.4 Radios planetarios en funci´on del tiempo. ......... 110 8.5 Radio planetario en funci´on del semieje mayor orbital. ............. 111 8.6 Magnitud de la estrella en la banda K (2MASS) versus la profundidad del eclipse secundario observadoen la bandaKs. 114 8.7 Radio planetario versus radiaci´on incidente. ............ 114 8.8 Radiaci´on incidente versus la temperatura de brillo observada en la banda Ks. 117 ′ 8.9 El ´ındice de actividad log(RHK) como funci´on de la temperatura de brillo en labandaKs. .................................... 119 10.1 Planetary radius versus incident radiation showing objects for future analysis. 126 List of Tables 3.1 Broad band photometric data of WTS-1. ..... 31 3.2 Broad band photometric data of WTS-2. ..... 39 3.3 Reconnaissance radial velocities of WTS-2 from CAHA 3.5m/TWIN. 41 3.4 Properties of the exoplanets WTS-1b and WTS-2b and their respective orbital parameters. ..................................... 45 4.1 ReferencestarsofWASP-10field.. ..... 50 4.2 Parameters of WASP-10b system considered in the analysis........... 55 5.1 ReferencestarsofQatar-1field.. ...... 68 5.2 Parameters of Qatar-1b system considered in the analysis............ 72 6.1 Total number of known transiting planetary systems. ........... 83 6.2 Known exoplanets with observed secondary eclipses in theKs-band. 92 8.1 N´umero total de sistemas planetarios conocidos que transitan.. 105 8.2 Exoplanetas conocidos con eclipses secundarios observados en la banda Ks.