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The Sun in its Youth

The Sun in its Youth. Alicia Aarnio. Outline. Stellar evolution timeline TTS: pre-main sequence Suns dM / dt dL/dt Solar-stellar connection Coronae Activity Magnetic fields. Stellar evolution in 1 slide. Hayashi track Henyey track Main sequence. 0.6 M . 1.4 M . 0.4 M .

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The Sun in its Youth

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  1. The Sun in its Youth Alicia Aarnio

  2. Outline • Stellar evolution timeline • TTS: pre-main sequence Suns • dM/dt • dL/dt • Solar-stellar connection • Coronae • Activity • Magnetic fields

  3. Stellar evolution in 1 slide • Hayashi track • Henyey track • Main sequence 0.6 M 1.4 M 0.4 M 0.2 M t [Myr] 105 yr 0.3 1.0 3.2 10.0 31.8 100.0 106 yr 2e6 yr 4e6 yr 107 yr Siess, Dufour & Forestini (2000) 2e7 yr 5e7 yr 108 yr Iben (1965) 5.5 6.0 6.5 7.0 7.5 8.0 log(t [Myr])

  4. Circumstellar disks • SEDs • Observations • RT modeling • Interferometry breaks degeneracies • Inclination • Revealed inner gap Booth+2009 881 Myr 873 Myr 1.2 Gyr JHK, late Class I Whitney+2003b

  5. Inner disk measurements • Long-baseline IR interferometry: resolution~λ/b • 2μm, 100m baseline  resolution ~4mas (0.6AU at 140pc) • Can presently measure visibilities (size), closure phase (shape- asymmetry?) Dust-free inner cavity Tuthill, Monnier & Danchi (2001) Dullemond & Monnier (2010)

  6. Interferometry • Transiting circumstellar disk observed with MIRC • Hot Jupiter atmosphere measurements Kloppenborg+2010 Stencel+2008 Zhao+2011

  7. Mass transfer in star-disk system Hartigan+1995 - Cranmer & Saar 2011 Haisch & Lada2 2001 Meyer+2008 - Wood+2005 Hadean Archean Preterozoic Phanerozoic

  8. Evolution of radiation field  Ingleby+2011 ✕ Getman+2005  Wright+2011 - Siess+2000  Ribas+2005 −Mamajek & Hillenbrand, 2008 Hadean Archean Preterozoic Phanerozoic

  9. Solar-stellar connection: X-ray properties Adapted from Schmitt (1997) • X-rays • X-ray emission properties like the Sun X9 flare Solar max Stellar and solar data Flares: Reale+2001 All else: Orlando+2001 From Marino+2002b Solar min Flares AR cores AR QC Figures from Peres+2004

  10. -----1-8Å -----0.5-4Å Solar-stellar connection: flares, fields • Magnetic activity • Flares much like the Sun, but more frequent, energetic Classifying TTS flares like solar, COUP flares = X300-X40,000! E. Flaccomio for COUP collaboration Getman+2005 Aarnio, Stassun & Matt (in prep)

  11. Ramifications for planet formation • Activity can impact planet formation • Chondrule formation via shock heating of CME hitting disk- Miura & Nakamoto (2007) • Composition of disk • Strong early winds, frequent CMEs • Atmospheric stripping • oxidation, chemistry changes • Understanding young exoplanet magnetospheres • Tidal forces on hot Jupiters- Trammell, Arras & Li (2011) • Star-planet magnetospheric interaction causing chromospheric variability- Shkolnik et al. (2008)

  12. Large-scale magnetic structure • Magnetic loops ~10R* • Cool plasma: prominences, ``clouds’’ (A. Collier Cameron, AB Dor) • Confining hot plasma: post-reconnection loops (UCL model, Reale+1997; applied to COUP Favata+2005) Collier Cameron & Robinson (1989a) Aarnio et al. (2012)

  13. Stellar CMEs • Post-flare loops: 1019-1022 g • Our stellar CME mass loss rates: ~10-9 – 10-11 M/yr Aarnio, Stassun & Matt (in prep)

  14. Summary • Sun-as-a-star and stars-as-suns valuable for better understanding both • Stellar evolution generally understood, but many issues remain • Rotation/activity relationship • B • Initial conditions in protosolar system • Chemistry • Disk structure • Angular momentum evolution

  15. Collaborators • UM: John Monnier, NuriaCalvet, Chuck Cowley • VU: KeivanStassun • CEA Saclay: Sean Matt • BU: Jeff Hughes, Sarah McGregor • Cal Tech: Scott Gregory • St Andrews: Moira Jardine, Joe Llama

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