arXiv subjects

Scott W. Fleming

Publications and source records attributed to Scott W. Fleming.

At least 55 records · Page 3Linked to original sources

arXiv2015

The Eleventh and Twelfth Data Releases of the Sloan Digital Sky Survey: Final Data from SDSS-III

The third generation of the Sloan Digital Sky Survey (SDSS-III) took data from 2008 to 2014 using the original SDSS wide-field imager, the original and an upgraded multi-object fiber-fed optical spectrograph, a new near-infrared high-resolution spectrograph, and a novel optical interferometer. All the data from SDSS-III are now made public. In particular, this paper describes Data Release 11 (DR11) including all data acquired through 2013 July, and Data Release 12 (DR12) adding data acquired through 2014 July (including all data included in previous data releases), marking the end of SDSS-III observing. Relative to our previous public release (DR10), DR12 adds one million new spectra of galaxies and quasars from the Baryon Oscillation Spectroscopic Survey (BOSS) over an additional 3000 sq. deg of sky, more than triples the number of H-band spectra of stars as part of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE), and includes repeated accurate radial velocity measurements of 5500 stars from the Multi-Object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The APOGEE outputs now include measured abundances of 15 different elements for each star. In total, SDSS-III added 2350 sq. deg of ugriz imaging; 155,520 spectra of 138,099 stars as part of the Sloan Exploration of Galactic Understanding and Evolution 2 (SEGUE-2) survey; 2,497,484 BOSS spectra of 1,372,737 galaxies, 294,512 quasars, and 247,216 stars over 9376 sq. deg; 618,080 APOGEE spectra of 156,593 stars; and 197,040 MARVELS spectra of 5,513 stars. Since its first light in 1998, SDSS has imaged over 1/3 of the Celestial sphere in five bands and obtained over five million astronomical spectra.

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arXiv2015

Target Selection for the SDSS-III MARVELS Survey

We present the target selection process for the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the Sloan Digital Sky Survey (SDSS) III. MARVELS is a medium-resolution ($R \sim 11000$) multi-fiber spectrograph capable of obtaining radial velocities for 60 objects at a time in order to find brown dwarfs and giant planets. The survey was configured to target dwarf stars with effective temperatures approximately between $4500$ and $6250 \, \mbox{K}$. For the first 2 years MARVELS relied on low-resolution spectroscopic pre-observations to estimate the effective temperature and $\log(g)$ for candidate stars and then selected suitable dwarf stars from this pool. Ultimately, the pre-observation spectra proved ineffective at filtering out giant stars; many giants were incorrectly classified as dwarfs, resulting in a giant contamination rate of $\sim$30\% for the first phase of the MARVELS survey. Thereafter, the survey instead applied a reduced proper motion cut to eliminate giants and used the Infrared Flux Method to estimate effective temperatures, using only extant photometric and proper-motion catalog information. The target selection method introduced here may be useful for other surveys that need to rely on extant catalog data for selection of specific stellar populations.

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arXiv2015

The APOGEE Spectroscopic Survey of Kepler Planet Hosts: Feasibility, Efficiency, and First Results

The Kepler mission has yielded a large number of planet candidates from among the Kepler Objects of Interest (KOIs), but spectroscopic follow-up of these relatively faint stars is a serious bottleneck in confirming and characterizing these systems. We present motivation and survey design for an ongoing project with the SDSS-III multiplexed APOGEE near-infrared spectrograph to monitor hundreds of KOI host stars. We report some of our first results using representative targets from our sample, which include current planet candidates that we find to be false positives, as well as candidates listed as false positives that we do not find to be spectroscopic binaries. With this survey, KOI hosts are observed over ~20 epochs at a radial velocity precision of 100-200 m/s. These observations can easily identify a majority of false positives caused by physically-associated stellar or substellar binaries, and in many cases, fully characterize their orbits. We demonstrate that APOGEE is capable of achieving RV precision at the 100-200 m/s level over long time baselines, and that APOGEE's multiplexing capability makes it substantially more efficient at identifying false positives due to binaries than other single-object spectrographs working to confirm KOIs as planets. These APOGEE RVs enable ancillary science projects, such as studies of fundamental stellar astrophysics or intrinsically rare substellar companions. The coadded APOGEE spectra can be used to derive stellar properties (T_eff, log(g)) and chemical abundances of over a dozen elements to probe correlations of planet properties with individual elemental abundances.

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arXiv2015

Planetary Candidates Observed by Kepler VI: Planet Sample from Q1-Q16 (47 Months)

\We present the sixth catalog of Kepler candidate planets based on nearly 4 years of high precision photometry. This catalog builds on the legacy of previous catalogs released by the Kepler project and includes 1493 new Kepler Objects of Interest (KOIs) of which 554 are planet candidates, and 131 of these candidates have best fit radii <1.5 R_earth. This brings the total number of KOIs and planet candidates to 7305 and 4173 respectively. We suspect that many of these new candidates at the low signal-to-noise limit may be false alarms created by instrumental noise, and discuss our efforts to identify such objects. We re-evaluate all previously published KOIs with orbital periods of >50 days to provide a consistently vetted sample that can be used to improve planet occurrence rate calculations. We discuss the performance of our planet detection algorithms, and the consistency of our vetting products. The full catalog is publicly available at the NASA Exoplanet Archive.

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arXiv2015

The Puzzling Li-rich Red Giant Associated with NGC 6819

A Li-rich red giant star (2M19411367+4003382) recently discovered in the direction of NGC 6819 belongs to the rare subset of Li-rich stars that have not yet evolved to the luminosity bump, an evolutionary stage where models predict Li can be replenished. The currently favored model to explain Li enhancement in first-ascent red giants like 2M19411367+4003382 requires deep mixing into the stellar interior. Testing this model requires a measurement of 12C/13C, which is possible to obtain from APOGEE spectra. However, the Li-rich star also has abnormal asteroseismic properties that call into question its membership in the cluster, even though its radial velocity and location on color-magnitude diagrams are consistent with membership. To address these puzzles, we have measured a wide array of abundances in the Li-rich star and three comparison stars using spectra taken as part of the APOGEE survey to determine the degree of stellar mixing, address the question of membership, and measure the surface gravity. We confirm that the Li-rich star is a red giant with the same overall chemistry as the other cluster giants. However, its log g is significantly lower, consistent with the asteroseismology results and suggestive of a very low mass if the star is indeed a cluster member. Regardless of the cluster membership, the 12C/13C and C/N ratios of the Li-rich star are consistent with standard first dredge-up, indicating that Li dilution has already occurred, and inconsistent with internal Li enrichment scenarios that require deep mixing.

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arXiv2014

Accurate Atmospheric Parameters at Moderate Resolution Using Spectral Indices: Preliminary Application to the MARVELS Survey

Studies of Galactic chemical and dynamical evolution in the solar neighborhood depend on the availability of precise atmospheric parameters (Teff, [Fe/H] and log g) for solar-type stars. Many large-scale spectroscopic surveys operate at low to moderate spectral resolution for efficiency in observing large samples, which makes the stellar characterization difficult due to the high degree of blending of spectral features. While most surveys use spectral synthesis, in this work we employ an alternative method based on spectral indices to determine the atmospheric parameters of a sample of nearby FGK dwarfs and subgiants observed by the MARVELS survey at moderate resolving power (R~12,000). We have developed three codes to automatically normalize the observed spectra, measure the equivalent widths of the indices and, through the comparison of those with values calculated with pre-determined calibrations, derive the atmospheric parameters of the stars. The calibrations were built using a sample of 309 stars with precise stellar parameters obtained from the analysis of high-resolution FEROS spectra. A validation test of the method was conducted with a sample of 30 MARVELS targets that also have reliable atmospheric parameters from high-resolution spectroscopic analysis. Our approach was able to recover the parameters within 80 K for Teff, 0.05 dex for [Fe/H] and 0.15 dex for log g, values that are lower or equal to the typical external uncertainties found between different high-resolution analyzes. An additional test was performed with a subsample of 138 stars from the ELODIE stellar library and the literature atmospheric parameters were recovered within 125 K for Teff, 0.10 dex for [Fe/H] and 0.29 dex for log g. These results show that the spectral indices are a competitive tool to characterize stars with the intermediate resolution spectra.

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arXiv2014

Revised Stellar Properties of Kepler Targets for the Quarter 1-16 Transit Detection Run

We present revised properties for 196,468 stars observed by the NASA Kepler Mission and used in the analysis of Quarter 1-16 (Q1-Q16) data to detect and characterize transiting exoplanets. The catalog is based on a compilation of literature values for atmospheric properties (temperature, surface gravity, and metallicity) derived from different observational techniques (photometry, spectroscopy, asteroseismology, and exoplanet transits), which were then homogeneously fitted to a grid of Dartmouth stellar isochrones. We use broadband photometry and asteroseismology to characterize 11,532 Kepler targets which were previously unclassified in the Kepler Input Catalog (KIC). We report the detection of oscillations in 2,762 of these targets, classifying them as giant stars and increasing the number of known oscillating giant stars observed by Kepler by ~20% to a total of ~15,500 stars. Typical uncertainties in derived radii and masses are ~40% and ~20%, respectively, for stars with photometric constraints only, and 5-15% and ~10% for stars based on spectroscopy and/or asteroseismology, although these uncertainties vary strongly with spectral type and luminosity class. A comparison with the Q1-Q12 catalog shows a systematic decrease in radii for M dwarfs, while radii for K dwarfs decrease or increase depending on the Q1-Q12 provenance (KIC or Yonsei-Yale isochrones). Radii of F-G dwarfs are on average unchanged, with the exception of newly identified giants. The Q1-Q16 star properties catalog is a first step towards an improved characterization of all Kepler targets to support planet occurrence studies.

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arXiv2014

The Tenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Apache Point Observatory Galactic Evolution Experiment

The Sloan Digital Sky Survey (SDSS) has been in operation since 2000 April. This paper presents the tenth public data release (DR10) from its current incarnation, SDSS-III. This data release includes the first spectroscopic data from the Apache Point Observatory Galaxy Evolution Experiment (APOGEE), along with spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS) taken through 2012 July. The APOGEE instrument is a near-infrared R~22,500 300-fiber spectrograph covering 1.514--1.696 microns. The APOGEE survey is studying the chemical abundances and radial velocities of roughly 100,000 red giant star candidates in the bulge, bar, disk, and halo of the Milky Way. DR10 includes 178,397 spectra of 57,454 stars, each typically observed three or more times, from APOGEE. Derived quantities from these spectra (radial velocities, effective temperatures, surface gravities, and metallicities) are also included.DR10 also roughly doubles the number of BOSS spectra over those included in the ninth data release. DR10 includes a total of 1,507,954 BOSS spectra, comprising 927,844 galaxy spectra; 182,009 quasar spectra; and 159,327 stellar spectra, selected over 6373.2 square degrees.

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arXiv2014

New Red Jewels in Coma Berenices

We have used Sloan Digital Sky Survey-III (SDSS-III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) radial velocity observations in the near-infrared $H$-band to explore the membership of the nearby ($86.7 \pm 0.9$ pc) open cluster Coma Berenices (Melotte 111), concentrating on the poorly-populated low-mass end of the main sequence. Using SDSS-III APOGEE radial velocity measurements, we confirm the membership of eight K/M dwarf members, providing the first confirmed low-mass members of the Coma Berenices cluster. Using $R\sim2000$ spectra from IRTF-SpeX, we confirm the independently luminosity classes of these targets, and find their metallicities to be consistent with the known solar mean metallicity of Coma Berenices and of M dwarfs in the Solar neighborhood. In addition, the APOGEE spectra have enabled measurement of $v\sin i$ for each target and detection for the first time of the low-mass secondary components of the known binary systems Melotte 111 102 and Melotte 111 120, as well as identification of the previously unknown binary system 2MASS J12214070+2707510. Finally, we use Kilodegree Extremely Little Telescope (KELT) photometry to measure photometric variability and rotation periods for a subset of the Coma Berenices members.

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arXiv2013

MARVELS-1: A face-on double-lined binary star masquerading as a resonant planetary system; and consideration of rare false positives in radial velocity planet searches

We have analyzed new and previously published radial velocity observations of MARVELS-1, known to have an ostensibly substellar companion in a ~6- day orbit. We find significant (~100 m/s) residuals to the best-fit model for the companion, and these residuals are naively consistent with an interior giant planet with a P = 1.965d in a nearly perfect 3:1 period commensuribility (|Pb/Pc - 3| < 10^{-4}). We have performed several tests for the reality of such a companion, including a dynamical analysis, a search for photometric variability, and a hunt for contaminating stellar spectra. We find many reasons to be critical of a planetary interpretation, including the fact that most of the three-body dynamical solutions are unstable. We find no evidence for transits, and no evidence of stellar photometric variability. We have discovered two apparent companions to MARVELS-1 with adaptive optics imaging at Keck; both are M dwarfs, one is likely bound, and the other is likely a foreground object. We explore false-alarm scenarios inspired by various curiosities in the data. Ultimately, a line profile and bisector analysis lead us to conclude that the ~100 m/s residuals are an artifact of spectral contamination from a stellar companion contributing ~15-30% of the optical light in the system. We conclude that origin of this contamination is the previously detected radial velocity companion to MARVELS-1, which is not, as previously reported, a brown dwarf, but in fact a G dwarf in a face-on orbit.

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arXiv2013

Very Low Mass Stellar and Substellar Companions to Solar-like Stars From MARVELS IV: A Candidate Brown Dwarf or Low-Mass Stellar Companion to HIP 67526

We report the discovery of a candidate brown dwarf or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 years. Our Keplerian fit using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of $90.2695^{+0.0188}_{-0.0187}$ days, an eccentricity of $0.4375 \pm 0.0040$ and a semi-amplitude of $2948.14^{+16.65}_{-16.55}$ m s$^{-1}$. Using additional high-resolution spectroscopy, we find the host star has an effective temperature $T_{\rm{eff}}=6004 \pm 34$ K, a surface gravity $\log g$ [cgs] $=4.55 \pm 0.17$ and a metallicity [Fe/H] $=+0.04 \pm 0.06$. The stellar mass and radius determined through the empirical relationship of Torres et al. (2010), yields 1.10$\pm$0.09 $M_{\sun}$ and 0.92$\pm$0.19 $R_{\sun}$. The minimum mass of MARVELS-5b is $65.0 \pm 2.9 M_{Jup}$, indicating that it is likely to be either a brown dwarf or a very low mass star, thus occupying a relatively sparsely-populated region of the mass function of companions to solar-type stars. The distance to this system is 101$\pm$10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2$M_{\sun}$ at a separation larger than 40 AU.

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arXiv2013

A Cautionary Tale: MARVELS Brown Dwarf Candidate Reveals Itself To Be A Very Long Period, Highly Eccentric Spectroscopic Stellar Binary

We report the discovery of a highly eccentric, double-lined spectroscopic binary star system (TYC 3010-1494-1), comprising two solar-type stars that we had initially identified as a single star with a brown dwarf companion. At the moderate resolving power of the MARVELS spectrograph and the spectrographs used for subsequent radial-velocity (RV) measurements (R ~ <30,000), this particular stellar binary mimics a single-lined binary with an RV signal that would be induced by a brown dwarf companion (Msin(i)~50 M_Jup) to a solar-type primary. At least three properties of this system allow it to masquerade as a single star with a very low-mass companion: its large eccentricity (e~0.8), its relatively long period (P~238 days), and the approximately perpendicular orientation of the semi-major axis with respect to the line of sight (omega~189 degrees). As a result of these properties, for ~95% of the orbit the two sets of stellar spectral lines are completely blended, and the RV measurements based on centroiding on the apparently single-lined spectrum is very well fit by an orbit solution indicative of a brown dwarf companion on a more circular orbit (e~0.3). Only during the ~5% of the orbit near periastron passage does the true, double-lined nature and large RV amplitude of ~15 km/s reveal itself. The discovery of this binary system is an important lesson for RV surveys searching for substellar companions; at a given resolution and observing cadence, a survey will be susceptible to these kinds of astrophysical false positives for a range of orbital parameters. Finally, for surveys like MARVELS that lack the resolution for a useful line bisector analysis, it is imperative to monitor the peak of the cross-correlation function for suspicious changes in width or shape, so that such false positives can be flagged during the candidate vetting process.

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arXiv2013

Very Low Mass Stellar and Substellar Companions to Solar-Like Stars From MARVELS V: A Low Eccentricity Brown Dwarf from the Driest Part of the Desert, MARVELS-6b

We describe the discovery of a likely brown dwarf (BD) companion with a minimum mass of 31.7 +/- 2.0 M_Jup to GSC 03546-01452 from the MARVELS radial velocity survey, which we designate as MARVELS-6b. For reasonable priors, our analysis gives a probability of 72% that MARVELS-6b has a mass below the hydrogen-burning limit of 0.072 M_Sun, and thus it is a high-confidence BD companion. It has a moderately long orbital period of 47.8929 +0.0063/-0.0062 days with a low eccentricty of 0.1442 +0.0078/-0.0073, and a semi-amplitude of 1644 +12/-13 m/s. Moderate resolution spectroscopy of the host star has determined the following parameters: T_eff = 5598 +/- 63, log g = 4.44 +/- 0.17, and [Fe/H] = +0.40 +/- 0.09. Based upon these measurements, GSC 03546-01452 has a probable mass and radius of M_star = 1.11 +/- 0.11 M_Sun and R_star = 1.06 +/- 0.23 R_Sun with an age consistent with less than ~6 Gyr at a distance of 219 +/- 21 pc from the Sun. Although MARVELS-6b is not observed to transit, we cannot definitively rule out a transiting configuration based on our observations. There is a visual companion detected with Lucky Imaging at 7.7 arcsec from the host star, but our analysis shows that it is not bound to this system. The minimum mass of MARVELS-6b exists at the minimum of the mass functions for both stars and planets, making this a rare object even compared to other BDs.

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arXiv2012

Very Low-mass Stellar and Substellar Companions to Solar-like Stars from Marvels III: A Short-Period Brown Dwarf Candidate Around An Active G0Iv Subgiant

We present an eccentric, short-period brown dwarf candidate orbiting the active, slightly evolved subgiant star TYC 2087-00255-1, which has effective temperature T_eff = 5903+/-42 K, surface gravity log (g) = 4.07+/-0.16 (cgs), and metallicity [Fe/H] = -0.23+/-0.07. This candidate was discovered using data from the first two years of the Multi-object APO Radial Velocity Exoplanets Large-area Survey (MARVELS), which is part of the third phase of Sloan Digital Sky Survey. From our 38 radial velocity measurements spread over a two-year time baseline, we derive a Keplerian orbital fit with semi-amplitude K=3.571+/-0.041 km/s, period P=9.0090+/-0.0004 days, and eccentricity e=0.226+/-0.011. Adopting a mass of 1.16+/-0.11 Msun for the subgiant host star, we infer that the companion has a minimum mass of 40.0+/-2.5 M_Jup. Assuming an edge-on orbit, the semimajor axis is 0.090+/-0.003 AU. The host star is photometrically variable at the \sim1% level with a period of \sim13.16+/-0.01 days, indicating that the host star spin and companion orbit are not synchronized. Through adaptive optics imaging we also found a point source 643+/-10 mas away from TYC 2087-00255-1, which would have a mass of 0.13 Msun if it is physically associated with TYC 2087-00255-1 and has the same age. Future proper motion observation should be able to resolve if this tertiary object is physically associated with TYC 2087-00255-1 and make TYC 2087-00255-1 a triple body system. Core Ca II H and K line emission indicate that the host is chromospherically active, at a level that is consistent with the inferred spin period and measured v_{rot}*sin i, but unusual for a subgiant of this T_eff. This activity could be explained by ongoing tidal spin-up of the host star by the companion.

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arXiv2012

The Metallicity of the CM Draconis System

The CM Draconis system comprises two eclipsing mid-M dwarfs of nearly equal mass in a 1.27-day orbit. This well-studied eclipsing binary has often been used for benchmark tests of stellar models, since its components are amongst the lowest mass stars with well-measured masses and radii (~ 1% relative precision). However, as with many other low-mass stars, non-magnetic models have been unable to match the observed radii and effective temperatures for CM Dra at the 5-10% level. To date, the uncertain metallicity of the system has complicated comparison of theoretical isochrones with observations. In this Letter, we use data from the SpeX instrument on the NASA Infrared Telescope Facility (IRTF) to measure the metallicity of the system during primary and secondary eclipses, as well as out of eclipse, based on an empirical metallicity calibration in the H and K near-infrared (NIR) bands. We derive a [Fe/H] = -0.30 +- 0.12 that is consistent across all orbital phases. The determination of [Fe/H] for this system constrains a key dimension of parameter space when attempting to reconcile model isochrone predictions and observations.

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arXiv2012

The Ninth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-III Baryon Oscillation Spectroscopic Survey

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2.32), and 90,897 new stellar spectra, along with the data presented in previous data releases. These spectra were obtained with the new BOSS spectrograph and were taken between 2009 December and 2011 July. In addition, the stellar parameters pipeline, which determines radial velocities, surface temperatures, surface gravities, and metallicities of stars, has been updated and refined with improvements in temperature estimates for stars with T_eff<5000 K and in metallicity estimates for stars with [Fe/H]>-0.5. DR9 includes new stellar parameters for all stars presented in DR8, including stars from SDSS-I and II, as well as those observed as part of the SDSS-III Sloan Extension for Galactic Understanding and Exploration-2 (SEGUE-2). The astrometry error introduced in the DR8 imaging catalogs has been corrected in the DR9 data products. The next data release for SDSS-III will be in Summer 2013, which will present the first data from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) along with another year of data from BOSS, followed by the final SDSS-III data release in December 2014.

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arXiv2012

Very Low-mass Stellar and Substellar Companions to Solar-like Stars from MARVELS II: A Short-period Companion Orbiting an F Star with Evidence of a Stellar Tertiary And Significant Mutual Inclination

We report the discovery via radial velocity of a short-period (P = 2.430420 \pm 0.000006 days) companion to the F-type main sequence star TYC 2930-00872-1. A long-term trend in the radial velocities indicates the presence of a tertiary stellar companion with $P > 2000$ days. High-resolution spectroscopy of the host star yields T_eff = 6427 +/- 33 K, log(g) = 4.52 +/- 0.14, and [Fe/H]=-0.04 +/- 0.05. These parameters, combined with the broad-band spectral energy distribution and parallax, allow us to infer a mass and radius of the host star of M_1=1.21 +/- 0.08 M_\odot and R_1=1.09_{-0.13}^{+0.15} R_\odot. We are able to exclude transits of the inner companion with high confidence. The host star's spectrum exhibits clear Ca H and K core emission indicating stellar activity, but a lack of photometric variability and small v*sin(I) suggest the primary's spin axis is oriented in a pole-on configuration. The rotational period of the primary from an activity-rotation relation matches the orbital period of the inner companion to within 1.5 σ, suggesting they are tidally locked. If the inner companion's orbital angular momentum vector is aligned with the stellar spin axis, as expected through tidal evolution, then it has a stellar mass of M_2 ~ 0.3-0.4 M_\odot. Direct imaging limits the existence of stellar companions to projected separations < 30 AU. No set of spectral lines and no significant flux contribution to the spectral energy distribution from either companion are detected, which places individual upper mass limits of M < 1.0 M_\odot, provided they are not stellar remnants. If the tertiary is not a stellar remnant, then it likely has a mass of ~0.5-0.6 M_\odot, and its orbit is likely significantly inclined from that of the secondary, suggesting that the Kozai-Lidov mechanism may have driven the dynamical evolution of this system.

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arXiv2012

The SDSS-HET Survey of Kepler Eclipsing Binaries: Spectroscopic Dynamical Masses of the Kepler-16 Circumbinary Planet Hosts

We have used high-resolution spectroscopy to observe the Kepler-16 eclipsing binary as a double-lined system, and measure precise radial velocities for both stellar components. These velocities yield a dynamical mass-ratio of q=0.2994+-0.0031. When combined with the inclination, i=90.3401+0.0016-0.0019 deg, measured from the Kepler photometric data by Doyle et al. 2011, we derive dynamical masses for the Kepler-16 components of M_A=0.654+-0.017 M_sun and M_B=0.1959+-0.0031 M_sun, a precision of 2.5% and 1.5% respectively. Our results confirm at the ~2% level the mass-ratio derived by Doyle et al. with their photometric-dynamical model, q=0.2937+-0.0006. These are among the most precise spectroscopic dynamical masses ever measured for low-mass stars, and provide an important direct test of the results from the photometric-dynamical modeling technique.

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