Christopher M. Johns-Krull (Rice University) IGRINS Science Workshop: August 26, 2010 Exploring the Planet Forming Environments of Young Suns

Star and Planet Formation

Central Engine & Fate of Disk Incorporated into Planets Accreted onto Star Lost in an Outflow Shu et al. (1994) Edwards et al. (1994) Disk locking

Stellar Magnetic Fields

Theoretical Predictions Konigl (1991): Cameron & Campbell (1993): Shu et al. (1994):

Measuring Fields from the Zeeman Effect

Zeeman Desaturation of Optical Lines Basri et al. (1992): 2 TTS Basri & Marcy (1994): Several dKe stars Guenther et al. (1999): 4 TTS Very sensitive to T eff Model with B/Model Without B Bf = 1.5 kG Bf = 1.7 kG Tap 35 EQ Vir Bf = 0? kG LkCa 16

Direct Zeeman Broadening Initial optical 2 line analyses were faulty

M Dwarf Fields in the Optical Johns-Krull & Valenti (1996, ApJ, 459, L95) McDonald Observatory 2dCoude Fe I Ti I TiO v sin i = 4.5 km/s  

Getting Rid of the TiO McDonald Observatory 2dCoude Johns-Krull & Valenti (1996, ApJ, 459, L95)

Going to the Infrared Kitt Peak 4m + FTS & NASA IRTF (3m) + CSHELL spectrometer R ~ 35,000-44,000 spectra Excess Broadening Seen in the Ti I line Saar & Linsky (1985) Johns-Krull et al. (1999)

TW Hya: CTTS Yang, Johns-Krull, & Valenti (2005)

Hubble 4: NTTS Johns-Krull, Valenti, & Saar (2004)

Predicted vs. Observed Mean Fields Caveats: Theory assumes dipole We measure mean field Uncertainty on x- axis difficult to quantify Additionally: no correlation with rotation rate, Rossby number, etc. Johns-Krull (2007)

YSOs in Other Regions Yang & Johns-Krull (2010) Yang et al. (2008) V1348 Ori B = 3.3 kG V1123 Ori B = 2.8 kG TWA 9A B = 3.2 kG WL 17 B = 2.9 kG Johns-Krull et al. (2009)

Building Planets: Mechanisms Timescale? Core Accretion Gravitational Instabilities

The Brown Dwarf Desert Grether and Lineweaver (2006)

Observational Clues Core Accretion: Dust collides and sticks together, building up larger bodies. May take about 10 Myr to build Jupiter. X GI: Gravitational instability leads to rapid planet formation. Fisher & Valenti (2005) Santos et al. (2004)

Observational Clues X Core Accretion: Dust collides and sticks together, building up larger bodies. May take about 10 Myr to build Jupiter. X GI: Gravitational instability leads to rapid planet formation. Marois et al. (2008) HR 8799 HL Tau Greaves et al. (2008) Dodson-Robinson et al. (2009)

Origin of the Desert Some feature (disk mass, disk lifetime, etc.) of the planet formation process prevents brown dwarfs forming Brown dwarfs do form, but then migrate in (Armitage & Bonnell 2002)

Search for Planets Around Young Stars

Young Star Properties ages 1-few Myr rotation periods 1-15 days visible photospheres classical & weak T Tauri Stars Herbst et al. (2002) Photometric Variability Valenti et al. (1993)

Coude spectrograph for stability observe faint and bright RV standards for uncertainties Th-Ar comps & cross correlation analysis Approach: Harlan J. Smith 2.7m telescope McDonald Young Planet Search Lisa Prato (Lowell Observatory) Naved Mahmud (Rice University) Chris Crockett (Lowell Observatory) Pat Hartigan (Rice University) Dan Jaffe (University of Texas) Marcos Huerta (AAS) Collaborators:

Testing the Approach RV standards show RMS ~120 m/s proof of concept: exoplanet HD 68988b (Butler+ 06) P=6.28d K=191m/s

Very Large Spots young, low-mass stars fully convective rotating rapidly convection and rotation drive strong dynamo & superspots observed photometrically and spectroscopically V410 Tau

Very Large Spots young, low-mass stars fully convective rotating rapidly convection and rotation drive strong dynamo & superspots observed photometrically and spectroscopically Hatzes (1995) V410 Tau

Line distortions also lead to apparent radial velocity variations Spots and Reflex Motion

Can We Tell the Difference? bisector span should correlate with the radial velocity if a spot is present yes (maybe!) spots induce spectral line asymmetries

Young RV Planets to Date Setiawan et al. (2007) identified long period (852d) planet around 100 Myr old star HD In 2008 team claimed detection of a 10M J, 10 Myr old TW Hya

Some Results No brown dwarf companions yet Some clearly spotted stars! Huerta et al. (2008)

Brown Dwarf: LP Martín et al. (2006)

Infrared Spectroscopy CSHELL spectrograph, cassegrain mounted on telescope flexure? No I 2 cell need Earth’s telluric lines for calibration (e.g., Blake et al. 2007, 2008)

Infrared Spectroscopy Model composite target spectrum with combination of stellar template (sunspot spectrum) and observed telluric spectrum (Prato et al. 2008) Nov 2008: 61 m/s Feb 2009: 31 m/s Nov 2009: 44 m/s Feb 2010: 97 m/s Overall: 69 m/s RV Precision

Ruling Out Interesting Candidates V827 Tau DN Tau Prato et al. (2008)

TW Hya: Planet or Spot? Setiawan et al. (2008): no line bisector radial velocity correlation? Huelamo et al. (2008): find correlation between line bisector and radial velocity Radial Velocity (m/s)

IR RV Variations Due to Spots V827 Tau Hubble 4

High Precision IR RV Bean et al. (2010)

Thank You

Disks Are Commonly Observed

From Disks to Planets

Measuring Stellar Magnetic Fields

Field Geometry: Polarization

The Photospheric Field of BP Tau

Emission Line Polarization He I Polarization Like looking only at the sunspots

Can “Map” the Stellar Field 7 nights in November 2009

K and M Star Results Pevtsov et al. (2003) Saar (1996) Field strength set by pressure balance with quiet photosphere Excellent Correlation with X-ray emission f and Bf correlated with rotation

Transition Disks Marois et al. (2008) Kalas et al. (2008) HR 8799 NASA

Transition Disks Najita et al. (2007)

Transition Disks Najita et al. (2007)

Accretion onto the Star A T Tauri star f ~ 0.01 Valenti et al. (1993) Garcia-Lopez et al. (2006) Gullbring et al. (1998)

T Tauri Stars: Magnetically Controlled Accretion Shu et al. (1994) Rotation correlated with disk signatures Balmer line profiles Accretion shock models reproduce optical veiling Edwards et al. (1994) Disk locking Theory gives field at some point in the disk Shu et al. (1994)

X-ray Luminosity vs Magnetic Flux F, G, and K Dwarfs Saar (1996) Solar Active Regions Fisher et al. (1998) Solar X-ray Bright Points Longcope et al. (2001) Quiet Sun at Solar Minimum Pevtsov & Acton (2000) T Tauri Stars Johns-Krull & Valenti (2000) Pevtsov et al. (2003)

Collaborators  Jeff Valenti (STScI)  Hao Yang (JILA)  Wei Chen (Rice)  Lisa Prato (Lowell Observatory)  Naved Mahmud (Rice University)  Chris Crockett (Lowell Observatory)  Pat Hartigan (Rice University)  Dan Jaffe (University of Texas)  Marcos Huerta (AIP/AVS)