<i>Y</i>
                    <sup>2</sup>
                    Isochrones with an Improved Core Overshoot Treatment

Demarque, P.; Woo, J. H.; Kim, Yong Cheol; Yi, Sukyoung K.

doi:10.1086/424966

Cited by 962 publications

(1,172 citation statements)

References 62 publications

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“…We reiterate the light-curve analysis after inferring the eccentricity vector posteriors from the TTV analysis to obtain a transit-model measurement of ρ å (Lissauer et al 2013;Jontof-Hutter et al 2014, 2015. Combining this estimate of ρ å with published stellar atmospheric values of the effective stellar temperature T eff , metallicity [Fe/H], and surface gravity g log , we matched stellar evolution models to estimate the stellar mass M å and radius R å (Demarque et al 2004). We checked for consistency between g log and  r based on stellar models and find good agreement (within 1σ) for all systems except for Kepler-49 (KOI-248) and Kepler-57 (KOI-1270).…”

Section: Stellar Parametersmentioning

confidence: 99%

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

Jontof-Hutter

Ford

Rowe

et al. 2016

ApJ

178

147

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We infer dynamical masses in eight multiplanet systems using transit times measured from Keplerʼs complete dataset, including short-cadence data where available. Of the 18dynamical masses that we infer, 10pass multiple tests for robustness. These are in systemsKepler-26 (KOI-250), Kepler-29 (KOI-738), Kepler-60 (KOI-2086), , and Kepler-307 (KOI-1576). Kepler-105 c has a radius of 1.3 R ⊕ and a density consistent with an Earth-like composition. Strong transit timing variation(TTV) signals were detected from additional planets, but their inferred masses were sensitive to outliers or consistent solutions could not be found with independently measured transit times, including planets orbitingKepler-49 (KOI-248), Kepler-57 (KOI-1270), Kepler-105 (KOI-115), and Kepler-177 (KOI-523). Nonetheless, strong upper limits on the mass of Kepler-177 c imply an extremely low density of∼0.1 g cm −3 . In most cases, individual orbital eccentricities were poorly constrained owingto degeneracies in TTV inversion. For five planet pairs in our sample, strong secular interactions imply a moderatetohigh likelihood of apsidal alignment over a wide range of possible eccentricities. We also find solutions for the three planets known to orbit Kepler-60 in a Laplace-like resonance chain. However, nonlibrating solutions also match the transittiming data. For six systems, we calculate more precise stellar parameters than previously known, enabling useful constraints on planetary densities where we have secure mass measurements. Placing these exoplanets on the mass-radius diagram, we find thata wide range of densities isobserved among sub-Neptune-mass planets and that the range in observed densities is anticorrelated with incident flux.

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Section: Stellar Parametersmentioning

confidence: 99%

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

Jontof-Hutter

Ford

Rowe

et al. 2016

ApJ

178

147

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“…Nominally the best fit to the radii is achieved at about 4.5 Myr with these models. We note, in passing, that other models such as those from the Yonsei-Yale series (Yi et al 2001;Demarque et al 2004) do not yield as good a fit, at least with the grid of standard compositions (X, Z) that are publicly available.…”

Section: Stellar Evolution Modelsmentioning

confidence: 92%

DI Herculis as a test of internal stellar structure and general relativity

Claret¹,

Torres

Wolf

2010

A&A

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Context. For the past three decades there has been a serious discrepancy between the observed and theoretical values of the apsidal motion rateω of the eccentric eclipsing binary DI Her, which has even been interpreted occasionally as a possible failure of general relativity (GR). A number of plausible explanations have been put forward. Recent observations of the Rossiter-McLaughlin effect have shown convincingly that the reason for the anomaly is that the rotational axes of the stars and the orbital axis are misaligned, which changes the predicted rate of precession significantly. Aims. Although the disagreement is now drastically smaller as a result of those measurements, it formally remains at the level of 50%, owing possibly to errors in the measured apsidal motion rate, outdated stellar models, or inaccuracies in the stellar parameters. The aim of this paper is to address each of these issues to improve the agreement even more. Methods. New times of minimum have been collected and used for redetermining of the apsidal motion rate. Based on the latest determinations of the absolute dimensions of the binary, we computed new stellar evolution models with updated physical inputs, and derived improved apsidal motion constants for the components. We performed Monte Carlo simulations to infer the theoretical distribution ofω, including the contributions from GR, as well as tidal and rotational distortions. All observational errors have been accounted for. Results. Our simulations yield a retrograde apsidal motion rate due to the rotationally-induced oblateness of −0.00056 deg cycle −1 (mode of the distribution), a GR contribution of +0.00068 deg cycle −1 , and a tidal contribution of +0.00034 deg cycle −1 , leading to a total predicted rate of +0.00046 deg cycle −1 . This is in excellent agreement with the newly measured value of +0.00042 deg cycle −1 . The formal difference is now reduced to 10%, a small fraction of the observational uncertainties.

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“…To obtain an improved estimate of the gravity, we used the Yale isochrones (Demarque et al 2004) and an IDL program by Yong et al (2013). However, the program failed to return a value for this very evolved RR Lyrae star.…”

Section: Stellar Parameters and Abundancesmentioning

confidence: 99%

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Hansen¹,

Rich

Koch

et al. 2016

A&A

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Low-mass variable high-velocity stars are interesting study cases for many aspects of Galactic structure and evolution. Until recently, the only known high-or hyper-velocity stars were young stars thought to originate from the Galactic center. Wide-area surveys such as APOGEE and BRAVA have found several low-mass stars in the bulge with Galactic rest-frame velocities higher than 350 km s −1 . In this study we present the first abundance analysis of a low-mass RR Lyrae star that is located close to the Galactic bulge, with a space motion of ∼-400 km s −1 . Using medium-resolution spectra, we derived abundances (including upper limits) of 11 elements. These allowed us to chemically tag the star and discuss its origin, although our derived abundances and metallicity, at [Fe/H] = −0.9 dex, do not point toward one unambiguous answer. Based on the chemical tagging, we cannot exclude that it originated in the bulge. However, its retrograde orbit and the derived abundances combined suggest that the star was accelerated from the outskirts of the inner (or even outer) halo during many-body interactions. Other possible origins include the bulge itself, or the star might have been stripped from a stellar cluster or the Sagittarius dwarf galaxy when it merged with the Milky Way.

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Y ² Isochrones with an Improved Core Overshoot Treatment

Cited by 962 publications

References 62 publications

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

DI Herculis as a test of internal stellar structure and general relativity

Chemical abundances in a high-velocity RR Lyrae star near the bulge

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Y 2 Isochrones with an Improved Core Overshoot Treatment

Cited by 962 publications

References 62 publications

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M ⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M ⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

DI Herculis as a test of internal stellar structure and general relativity

Chemical abundances in a high-velocity RR Lyrae star near the bulge

Contact Info

Product

Resources

About

Y ² Isochrones with an Improved Core Overshoot Treatment

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES

SECURE MASS MEASUREMENTS FROM TRANSIT TIMING: 10 KEPLER EXOPLANETS BETWEEN 3 AND 8 M _⊕ WITH DIVERSE DENSITIES AND INCIDENT FLUXES