joachim saur, timo grambusch , stefan duling university of cologne, germany
DESCRIPTION
Moon-Planet and Exoplanet -Star Couplings: Common Electrodynamic Interaction Mechanisms Throughout the Universe. Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany. Magnetic coupling: Satellite-planet. Clarke et al., 2002. Magnetic coupling : Planet-star. - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/1.jpg)
Moon-Planet and Exoplanet-Star Couplings: Common Electrodynamic Interaction Mechanisms
Throughout the Universe
Joachim Saur, Timo Grambusch, Stefan Duling
University of Cologne, Germany
![Page 2: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/2.jpg)
Magnetic coupling: Satellite-planet
Clarke et al., 2002
![Page 3: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/3.jpg)
Magnetic coupling: Planet-star
Radial distribution of Exoplanets Evidence for Planet-Star Coupling: HD 179949
Skolnik et al. (2003, 2005, 2008)Ca 3947 A line correlation with orbital period of 3.1 dEnergy flux: 1020 W
![Page 4: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/4.jpg)
Our aim:• Electromagnetic planet-star interaction for exoplanets has
been studied by: – Ip et al. (2004), – Preusse et al. (2005, 2006)– Grießmeier et al. (2004, 2007)– Zarka (2007)– Lanza (2008, 2009)– Nichols (2011)– Poppenhaeger et a. (2010, 2011)
• This work: Energetics of the coupling, which is dominated by the Poynting flux.
![Page 5: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/5.jpg)
Model for energy flux• Calculate Poynting flux S= (E x B)/μ0 • Based on Alfven wing model by Neubauer (1980).
Kivelson et al. 2004 Neubauer 1998
With internal field Exoplanet geometryStandard case
![Page 6: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/6.jpg)
Total Poynting flux launched at satellite/planet
Limitation: No considerations about the fate of the energy along the flux tube No partially reflection/transmission (Hess et al. 2010a,2010b) considered.
No nonlinear reflection at central body (Jacobsen et al. 2007) considered.No conversion of Poynting flux into particle acceleration considered.
![Page 7: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/7.jpg)
Benchmarking at Jupiter and Saturn
• Io: – Theory: 2 x 1012 W– UV Observations: 1-10 x 1010
W • Europa:
– Theory: 1-7 x 1010 W– UV Observations: 1-5 x 108 W
• Ganymede: – Theory: 1-3 x 1011 W– UV Observations: 2-15 x 108 W
• Callisto:– Theory: 0.3-6 x 109 W
• Enceladus:– Theory: 2x108 W– UV Observations: 106-107 W
![Page 8: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/8.jpg)
Estimated MA at all known 562* exoplanets * until last Friday
![Page 9: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/9.jpg)
Poynting flux for 192 exoplanets with MA<1
![Page 10: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/10.jpg)
Summary
• Electromagnetic planet star coupling is possible if relative flow velocity < Alfven velocity. 192 of 562 exoplanets exhibit sub-Alfvenic interaction.
• Only a few exoplanets generate energy fluxes large enough to be detectable.
• HD 179949 b produces 1020 W if both exoplanet and star have magnetic fields 10 x stronger than Jupiter and sun, respectively.
![Page 11: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/11.jpg)
![Page 12: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/12.jpg)
![Page 13: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/13.jpg)
Parker Model for Properties near 564 Exoplanets
![Page 14: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/14.jpg)
Modelled Energy Flux:HD179949 and companion
TS= 9d, FM = 1010 kg/s, r=0.045 AU, RS=1.19 Rsun, T=107 K, spectral class: F8V
![Page 15: Joachim Saur, Timo Grambusch , Stefan Duling University of Cologne, Germany](https://reader035.vdocuments.net/reader035/viewer/2022062218/56815b4b550346895dc92db9/html5/thumbnails/15.jpg)