Cool Stars 19 Talk
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This document discusses using eclipsing binary red giants to test asteroseismic scaling relations. The author identified 19 red giants in eclipsing binary systems from Kepler data. Most systems oscillate, but 4 do not. For one well-characterized equal-mass binary system, modeling of light curves and radial velocities directly measured the stars' properties. Comparison to asteroseismic analysis showed the scaling relations overestimate mass and radius. The author suggests tides and magnetism in close, circularized binary systems dampen oscillations. Red giant binaries provide benchmarks to test and improve asteroseismic analysis techniques.
![Meredith L. Rawls @merrdiff
Pipeline comparisons: Teff, [Fe/H], log g
Gaulme et al. submitted](https://image.slidesharecdn.com/coolstars19mrawlstalk-160610220346/85/Cool-Stars-19-Talk-6-320.jpg)
![Meredith L. Rawls @merrdiff
Asteroseismic scalings
overestimate M and R
0.8 1 1.2 1.4 1.6 1.8 2 2.2
0.8
1
1.2
1.4
1.6
1.8
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2.2
Dynamical mass [M]
Asteroseismicmass[M]
Seismicmass(M)
Dynamic mass (M)
16%
*
8 9 10 11 12 13 14
8
9
10
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14
Dynamical radius [R]
Asteroseismicradius[R]
Dynamic radius (R)
Seismicradius(R)
6%
*
Gaulme et al. submitted](https://image.slidesharecdn.com/coolstars19mrawlstalk-160610220346/85/Cool-Stars-19-Talk-9-320.jpg)
Cool Stars 19 Talk
- 1. Red Giants in Eclipsing Binaries Exploring Non-Oscillators and Testing Asteroseismic Scalings Meredith L. Rawls New Mexico State University University of Washington/LSST (Fall 2016) June 10, 2016 Cool Stars 19 @merrdiff Image: G Perez, IAC, SMM In collaboration with P. Gaulme, J. McKeever, J. Jackiewicz, et al.
- 2. Meredith L. Rawls @merrdiff Eclipsing binaries with light curves and radial velocities let us directly measure M, R Asteroseismology is a powerful tool to characterize lots of stars quickly, using light curves alone We can study oscillating stars in eclipsing binaries from two independent perspectives A set of well-characterized binaries lets us explore why some dont oscillate when we think they should How to measure stellar properties?
- 3. Meredith L. Rawls @merrdiff Kepler red giant catalog: ~14,000 Kepler eclipsing binary catalog: 2,500+ After cross-correlating: 19 Most systems are SB2, but 4 are SB1 Most are oscillators, but 4 are not Searching for red giants in eclipsing binary systems Gaulme et al. 2013 & 2014
- 4. Meredith L. Rawls @merrdiff 僚 僚max Power Frequency 僚 Acoustic pressure modes Buoyant gravity modes Evolutionary state Scaling relations Characterizing a star: asteroseismology
- 5. Meredith L. Rawls @merrdiff Characterizing a star: binary modeling 9.30 9.35 9.40 9.45 9.50 Magnitude ELC Model 60 40 20 0 20 40 RadialVelocity(kms1 ) 0.0 0.2 0.4 0.6 0.8 1.0 0.004 0.000 0.004 2 0 2 9.25 9.30 9.35 9.40 9.45 9.50 Magnitude 0.20 0.21 0.22 0.23 0.004 0.000 0.004 0.49 0.50 0.51 0.52 Orbital Phase (conjunction at = 0.5) Secondary Primary Double red giant KIC 9246715 Stars are nearly twins Simultaneously 鍖t radial velocities and light curve Rawls et al. 2016 Radial velocities Kepler light curve Eclipse zoom KIC 9246715
- 6. Meredith L. Rawls @merrdiff Pipeline comparisons: Teff, [Fe/H], log g Gaulme et al. submitted
- 7. Meredith L. Rawls @merrdiff Tides and magnetism affect oscillations P = 20 d e ~ 0 non-oscillator P = 207 d e = 0.23 oscillator Rawls et al. in prep
- 8. Meredith L. Rawls @merrdiff Tides and magnetism affect oscillations Observede expect e ~ 0 expect e > 0 short P long P Rawls et al. in prep Predicted change in eccentricity from stellar evolution modeling Non-oscillators have short P, circularized orbits, and spots
- 9. Meredith L. Rawls @merrdiff Asteroseismic scalings overestimate M and R 0.8 1 1.2 1.4 1.6 1.8 2 2.2 0.8 1 1.2 1.4 1.6 1.8 2 2.2 Dynamical mass [M] Asteroseismicmass[M] Seismicmass(M) Dynamic mass (M) 16% * 8 9 10 11 12 13 14 8 9 10 11 12 13 14 Dynamical radius [R] Asteroseismicradius[R] Dynamic radius (R) Seismicradius(R) 6% * Gaulme et al. submitted
- 10. Meredith L. Rawls @merrdiff Solar-like oscillations are damped by magnetism & tides, which occur together Scaling relations overestimate giant M, R These stars are references for survey pipelines Asteroseismic surveys underestimate ages and exclude active stars and close binaries Red giant binaries are powerful benchmarks for asteroseismology