Angular Resolution Universe. Universe

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1 High High Angular Angular Resolution Resolution Universe Universe Gail Schaefer The CHARA Array of Georgia State University Mount Wilson, CA

2 Angular Angular Resolution Resolution Angular Resolution - Visible Current telescope limit Nic Scott ~ 80 x better resolution than current largest telescopes Next-gen telescope limit COAST ISI NPOI 0.20 mas

3 Long Long Baseline Baseline Optical/Infrared Optical/Infrared Interferometers Interferometers CHARA Array - Mount Wilson, CA NPOI - Anderson Mesa, AZ VLTI - Paranal, Chile MROI - Magdalena Ridge, NM (under construction)

4 log L (L ) Stellar Stellar Diameters Diameters Empirical HRD ~ 290 stars, σθ < 5% Angular diameter + parallax Linear radius

5 log L (L ) Stellar Stellar Diameters Diameters Empirical HRD ~ 290 stars, σθ < 5% Angular diameter + parallax Linear radius Effective Temperature Boyajian et al F bol = 14 θ2 σ T 4

6 Stellar Stellar Ages Ages Comparison of R, Teff, L with evolutionary models Masses and ages of stars log R/R Jones et al log Teff [K]

7 Exoplanet Exoplanet Host Host Stars Stars GJ 876 Size of habitable zones Age and mass of host star Physical parameters of planets von Braun et al L, Teff Radius of transiting planets

8 Power spectral density) Asteroseismology Asteroseismology νmax Chaplin & Miglio (2013) <νnl> Frequency (μhz) Mass, radius, mean density, and surface gravity (need Teff) Kepler and CoRoT Targets νmax (M / R2) (Teff)-0.5 <νnl> <ρ>0.5 Oscillation power spectrum <νnl>: frequency separation of modes νmax: frequency of maximum power Test asteroseismic scaling relations for main sequence stars Huber et al. (2012)

9 Imaging Imaging Stellar Stellar Surfaces Surfaces Zet And θ = 2.5 mas Gravity darkening Magnetically active star Limb darkening Persistent polar spot Transient lower latitude spots Roettenbacher et al Monnier et al. 2007, Zhao et al. 2009, Che et al. 2011

10 Imaging Imaging Stellar Stellar Surfaces Surfaces Zet And θ = 2.5 mas Gravity darkening Magnetically active star Limb darkening Persistent polar spot Transient lower latitude spots Roettenbacher et al Monnier et al. 2007, Zhao et al. 2009, Che et al. 2011

11 Binary Binary Stars Stars Spatially resolved orbits of spectroscopic binaries Schaefer et al. (2016) Zhao et al. (2008) Masses and distances to 1-3% precision Mass transfer - interacting High contrast companions Separations mas ΔH < 6 mag Gallenne et al. 2015, Roettenbacher et al. 2015

12 Circumstellar Circumstellar Disks Disks Gam Cas Gies et al. (2007) Geometry and physical structure of disks Kinematic structure

13 Future Future Science Science Prospects Prospects

14 Transiting Transiting Exoplanet Exoplanet Survey Survey Satellite Satellite TESS TESS TESS Input Catalog 596 million objects 200, ,000 selected for high cadence Two-year mission Launch in 2018 Image credit: NASA

15 TESS TESS Input Input Catalog: Catalog: Stars Stars Resolvable Resolvable at at CHARA CHARA in in R-band R-band R-band with 330 m baseline λ = 650 nm Resolution = 0.20 mas Limiting magnitude V = 7 mag 4,864 stars resolvable Expected with AO: V = 8 mag 13,922 stars resolvable

16 Time Time Domain Domain Surveys: Surveys: Follow-up Follow-up on on Bright Bright Transient Transient Events Events

17 Time Time Domain Domain Surveys: Surveys: Follow-up Follow-up on on Bright Bright Transient Transient Events Events Transit Images Kloppenborg et al. (2010)

18 Time Time Domain Domain Surveys: Surveys: Follow-up Follow-up on on Bright Bright Transient Transient Events Events Transit Images Nova Explosions Angular expansion Geometric Distance Asymmetries Nova Del 2013 Schaefer et al. (2014)

19 Time Time Domain Domain Surveys: Surveys: Follow-up Follow-up on on Bright Bright Transient Transient Events Events Transit Images Nova Explosions Angular expansion Geometric Distance Asymmetries Microlensing Image size and shape Break degeneracy between lens mass and distance Cassan & Ranc (2016)

20 Stellar Stellar Structure Structure and and Convection Convection Model of Convection for Red Supergiant Chiavassa et al. (2010) Direct measurements of limb darkening as probe of atmospheric structure Starspots and magnetic activity Convection and granulation

21 Active Active Galactic Galactic Nuclei Nuclei C.M. Urry and P. Padovani Geometry of dust torus Inner dust sublimation region Relationship between geometry and luminosity Temperature profile Molecular cloud distribution

22 Planet Planet Formation Formation Imager Imager Thermal IR imaging interferometer with <1 milliarcsecond resolution to resolve giant planet formation processes down to the scale of circumplanetary accretion disks PFI will unveil the dynamical processes that shape the architecture of planetary systems Monnier et al. 2016, Kraus et al. 2016

23 Open Open Access Access Time Time at at the the CHARA CHARA Array Array Community access time at CHARA Public database of archival data Supported by NSF/MSIP Time allocated through NOAO TAC Provides 50 nights/year over next four years Average over-subscription rate ~ 2.2

24 LBOI LBOI Roadmap Roadmap for for Decadal Decadal Community access time for optical/infrared interferometers Upgrades to existing facilities Installation of AO - efficiency Longer baselines - resolution Larger apertures - sensitivity Technological developments for future arrays Planet Formation Imager NASA interferometric missions in the Visionary Era: habitable planets, earliest stages of star formation, black hole event horizons, AGN