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WARM SPITZER PHASE VARIATIONS OF WASP-12B: DEFYING PREDICTIONS Nick Cowan CIERA Postdoctoral Fellow Northwestern University September 15 th 2011 with Louis.

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Presentation on theme: "WARM SPITZER PHASE VARIATIONS OF WASP-12B: DEFYING PREDICTIONS Nick Cowan CIERA Postdoctoral Fellow Northwestern University September 15 th 2011 with Louis."— Presentation transcript:

1 WARM SPITZER PHASE VARIATIONS OF WASP-12B: DEFYING PREDICTIONS Nick Cowan CIERA Postdoctoral Fellow Northwestern University September 15 th 2011 with Louis Shekhtman (NU undergrad) Machalek, Croll, Burrows, Deming

2 Sept 15, 2011Nick Cowan's Talk at ESS II2 WASP-12b: a Tortured World ~1 day orbit: Oblate Planet Tidally Warped: Prolate Planet T day ≈3000 K: MHD Effects Big R p, small a: Roche-Lobe Overflow Accretion on Star/ Bow Shock Peculiar Eclipse Depths: High C/O ratio (Hebb et al. 2009; Ragozzine & Wolf 2009; Li et al. 2010; Lai et al. 2011; Leconte et al. 2011; Fossati et al. 2010; Vidotto et al. 2010; Llama et al. 2011; Madhusudhan et al. 2011) Check Out These Posters: Crossfield 40.08 Petigura 33.03 Moses 40.04 Li et al. (2010)

3 Sept 15, 2011Nick Cowan's Talk at ESS II3 Thermal + Ellipsoidal Variations HAT-P-7b as seen by Kepler (Welsh et al. 2010) Brightness Phases: Planet Light Geometrical Phases: Projected Area Optical Light Observations Reflected Light Dominates Phases Star’s Shape Dominates Geometry Infrared Observations Thermal Emission Dominates Phases Planet’s Shape Dominates Geometry

4 Sept 15, 2011Nick Cowan's Talk at ESS II4 Raw WASP-12b Photometry 3.6 micron 4.5 micron Transit Eclipse Phase Function Intra-pixel sensitivity variations are the dominant systematic 1.Gaussian Decorrelation (Ballard et al. 2010) 2.Polynomial in Centroid x and y

5 Sept 15, 2011Nick Cowan's Talk at ESS II5 WASP-12b at 3.6 micron  max = -53(7)° A therm / = 0.9(3)

6 Sept 15, 2011Nick Cowan's Talk at ESS II6 What Planets Are Supposed To Do Noon SOP Dawn SOP Midnight SOP Dusk SOP Increasing Heat Capacity 1) Decreases Thermal Phase Amplitude 2) Increases Hot Spot Offset Cowan & Agol (2011a)

7 Sept 15, 2011Nick Cowan's Talk at ESS II7 WASP-12b at 3.6 micron  max = -53(7)° A ellips = 2(2)x10 -4 A therm / = 0.9(3)

8 Sept 15, 2011Nick Cowan's Talk at ESS II8 WASP-12b at 4.5 micron  max = -16(4)° A ellips = 1.2(2)x10 -4 A therm / = 0.7(1) The Null Hypothesis Consistent with Cowan & Agol (2011a) Toy Model

9 Sept 15, 2011Nick Cowan's Talk at ESS II9 Interpreting Ellipsoidal Variations 4.5 micron phase variations Temperature profile is cos(  -  0 ) some of cos(2  ) due to temperature All of cos(2  ) due to temperature cos(2  ) all due to geometry Spherical planet most of cos(2  ) due to geometry But applying Cowan & Agol (2008) deconvolution leads to unphysical longitudinal brightness map Geometry Phases Brightness

10 Sept 15, 2011Nick Cowan's Talk at ESS II10 Day-Side Emergent Spectrum Day-Side 1D Model Spectra (Burrows et al. 2007, 2008) (Croll et al. 2011) (López- Morales et al. 2010) (Campo et al. 2010) This Study Null Hypothesis

11 Sept 15, 2011Nick Cowan's Talk at ESS II11 Transmission Spectrum (Chan et al. 2011) (Maciejewski et al. 2011) Transit Spectrum Assuming Day-Like T-P Profile (Burrows et al. 2007, 2008)

12 Sept 15, 2011Nick Cowan's Talk at ESS II12 Choose Your Own Adventure 1. Prediction-Buster Roche-Lobe Opaque at 4.5  m + Gravity Brightened Terminator Weird Composition (not just high C/O) 2. Null Hypothesis Ellipsoidal Variations As Predicted Solar Composition?

13 Sept 15, 2011Nick Cowan's Talk at ESS II13 WASP-12b Power Budget Eclipse Observations Phase Observations A B ≈ 0.25  ≈  rad /(  adv +  rad ) ≈ 0.1 Hot Planets are Poor Recirculators (Cowan & Agol 2011b) 1.Magnetic Drag (Perna et al. 2010, Menou 2011) 2.Short Radiative Timescale (  rad ≈ T -3 )

14 Sept 15, 2011Nick Cowan's Talk at ESS II14 EXOCLIMES 2012 Aspen, CO Jan 16-20, 2012 Registration Open www.aspenphys.org


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