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The Sun

The Sun. Understanding our Star with Polarimetry Silvano Fineschi INAF – Astrophysical Observatory of Torino - Italy. Internatonal School of Astropolarimetry Centre Paul Langevin Aussois (F), 3-8 June 2013. The Solar Dynamo : Powering the Sun’s magnetic field.

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The Sun

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  1. The Sun Understandingour Star with Polarimetry Silvano Fineschi INAF – AstrophysicalObservatory of Torino - Italy Internatonal School of Astropolarimetry Centre Paul LangevinAussois (F), 3-8 June 2013

  2. The Solar Dynamo: Powering the Sun’smagneticfield • In the Sun, the magneticfieldgenerated by the dynamomechanismplays a centralrole in the dynamics of the solar atmosphere. • Solar polarityreverses in about 11 years (solar cycle) • The plasma dynamics in the solar atmospheregoes from beingdominated by thermal pressure (kT) over the magnetic pressure (B2) in the photosphere (1 <  = kT/ B2) to the opposite in chromosphere, corona ( 1 > )

  3. The Solar Magnetic Field: Powering the Sun’satmosphere • Magneticreconnectionpowers solar flares and Coronal Mass Ejections • Magneticwaves (Alfven, acoustic)/reconnection (nanoflares) (TBD) power the solar wind

  4. Solar Filter-Magnetograph

  5. Solar Spectro-Polarimeter

  6. HanleEffect(tutorial) Larmour<< A Larmour A

  7. Hanleeffect in photosphericlines

  8. Hanleeffect in chromosphericHI Lyman- line

  9. CLASP sounding-rocket: measuring the Hanleeffect in HI Lyman-

  10. Hanle effect Sensitivity in coronal lines A [107 s-1] ~ 0.88  gJ  B [G] A FeXIII= 14 Hz  BHanle 0.2-2 G A FeXIII<<Bcorona(“saturated” Hanleeffect) Fineschi, van Ballegooijen & Kohl, 1999

  11. HanleEffect(tutorial) If Larmour >> A (VIR forbiddenlines) Larmour>> A  Pis // or  B A FeXIII= 14 Hz  BHanle 0.2-2 G A FeXIII<<Bcorona(“saturated” Hanleeffect)

  12. HAO CoMP LC Lyotfiter & PolarimeterFeXIII 1047.4 nm «forbidden line» S. Tomczyk, et al. Science 317, 1192 (2007);

  13. Resonance-scatteringPolarization

  14. Anisotropic Super-radialDoppler-dimmingeffect OVI 103.7 nmDoppler-dimming; CII pumping (S. Giordano courtesy) Fineschi, ASP Conf. Series, 2001

  15. SUMER Measurement of Hanle and ASD effects? P=(92)%; = 96 Helioctr. Dist. = 1.3 R Wind speed w  40 km/s (RauoafiA&A 1999) Hanleeffect: B > 10 G; B < 10; w > 50 km/s SR Doppler-dim.: B < 3 G; B > 30; w > 50 km/s Anisotr. SR Doppler-dim.: B <<1 G; B  20; w  40 km/s (Fineschi ASP Conf. Series 2001)

  16. SolmeX – COMPASS (ESA M-mission) Peter, Fineschi et al. Exp. Astron. 2011

  17. Coronal UV Spectro-Polarimeter (CUPS)

  18. Non-Formation Flying CUPS Telescopeexternallyocculted withmulti-stackedapertures Moses, et al. SPIE 2011

  19. Beta 10 Ro HI Lyman series, OVI 103.2 nm & Fe IR lines 2 Ro 1.05 Ro SUMI SolmeX CIV 150 nm MgII h & k 280 nm Temp. minimum HI Ly- 122 nm CLASP Photospheric VIR lines ProbingCoronalMagnetismwithSpace EUV/UV/VIR Polarimetry

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