- ID:
- ivo://CDS.VizieR/J/ApJ/743/141
- Title:
- T dwarf companions around M, L, T dwarfs in IR
- Short Name:
- J/ApJ/743/141
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report observational techniques, results, and Monte Carlo population analyses from a Spitzer Infrared Array Camera imaging survey for substellar companions to 117 nearby M, L, and T dwarf systems (median distance of 10pc, mass range of 0.6 to ~0.05M_{sun}_). The two-epoch survey achieves typical detection sensitivities to substellar companions of [4.5um]<=17.2mag for angular separations between about 7" and 165". Based on common proper motion analysis, we find no evidence for new substellar companions. Using Monte Carlo orbital simulations (assuming random inclination, random eccentricity, and random longitude of pericenter), we conclude that the observational sensitivities translate to an ability to detect 600-1100K brown dwarf companions at semimajor axes >~35AU and to detect 500-600 K companions at semimajor axes >~60AU. The simulations also estimate a 600-1100K T dwarf companion fraction of <3.4% for 35-1200AU separations and <12.4% for the 500-600K companions for 60-1000AU separations.
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Search Results
- ID:
- ivo://CDS.VizieR/J/ApJ/892/31
- Title:
- Teff and metallicities of M dwarfs in APOGEE DR14
- Short Name:
- J/ApJ/892/31
- Date:
- 07 Mar 2022 13:23:27
- Publisher:
- CDS
- Description:
- M dwarfs have enormous potential for our understanding of structure and formation on both Galactic and exoplanetary scales through their properties and compositions. However, current atmosphere models have limited ability to reproduce spectral features in stars at the coolest temperatures (Teff<4200K) and to fully exploit the information content of current and upcoming large-scale spectroscopic surveys. Here we present a catalog of spectroscopic temperatures, metallicities, and spectral types for 5875 M dwarfs in the Apache Point Observatory Galactic Evolution Experiment (APOGEE) and Gaia-DR2 surveys using The Cannon (Ness+ 2015, J/ApJ/808/16 ; Casey+ 2016, arXiv:1603.03040; Ho+ 2017, J/ApJ/836/5; Behmard+ 2019ApJ...876...68B): a flexible, data-driven spectral-modeling and parameter-inference framework demonstrated to estimate stellar-parameter labels (Teff, logg, [Fe/H], and detailed abundances) to high precision. Using a training sample of 87 M dwarfs with optically derived labels spanning 2860K<Teff<4130K calibrated with bolometric temperatures, and -0.5<[Fe/H]<0.5dex calibrated with FGK binary metallicities, we train a two-parameter model with predictive accuracy (in cross-validation) to 77K and 0.09dex respectively. We also train a one-dimensional spectral classification model using 51 M dwarfs with Sloan Digital Sky Survey optical spectral types ranging from M0 to M6, to predictive accuracy of 0.7 types. We find Cannon temperatures to be in agreement to within 60 K compared to a subsample of 1702 sources with color-derived temperatures, and Cannon metallicities to be in agreement to within 0.08 dex metallicity compared to a subsample of 15 FGK+M or M+M binaries. Finally, our comparison between Cannon and APOGEE pipeline (ASPCAP DR14) labels finds that ASPCAP is systematically biased toward reporting higher temperatures and lower metallicities for M dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJ/800/85
- Title:
- Teff, radii and luminosities of cool dwarfs
- Short Name:
- J/ApJ/800/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Interferometric radius measurements provide a direct probe of the fundamental parameters of M dwarfs. However, interferometry is within reach for only a limited sample of nearby, bright stars. We use interferometrically measured radii, bolometric luminosities, and effective temperatures to develop new empirical calibrations based on low-resolution, near-infrared spectra. We find that H-band Mg and Al spectral features are good tracers of stellar properties, and derive functions that relate effective temperature, radius, and log luminosity to these features. The standard deviations in the residuals of our best fits are, respectively, 73K, 0.027R_{sun}_, and 0.049dex (an 11% error on luminosity). Our calibrations are valid from mid K to mid M dwarf stars, roughly corresponding to temperatures between 3100 and 4800K. We apply our H-band relationships to M dwarfs targeted by the MEarth transiting planet survey and to the cool Kepler Objects of Interest (KOIs). We present spectral measurements and estimated stellar parameters for these stars. Parallaxes are also available for many of the MEarth targets, allowing us to independently validate our calibrations by demonstrating a clear relationship between our inferred parameters and the stars' absolute K magnitudes. We identify objects with magnitudes that are too bright for their inferred luminosities as candidate multiple systems. We also use our estimated luminosities to address the applicability of near-infrared metallicity calibrations to mid and late M dwarfs. The temperatures we infer for the KOIs agree remarkably well with those from the literature; however, our stellar radii are systematically larger than those presented in previous works that derive radii from model isochrones. This results in a mean planet radius that is 15% larger than one would infer using the stellar properties from recent catalogs. Our results confirm the derived parameters from previous in-depth studies of KOIs 961 (Kepler-42), 254 (Kepler-45), and 571 (Kepler-186), the latter of which hosts a rocky planet orbiting in its star's habitable zone.
- ID:
- ivo://CDS.VizieR/J/AJ/157/82
- Title:
- TEMP. V. Photometry of HAT-P-9, HAT-P-32 & HAT-P-36
- Short Name:
- J/AJ/157/82
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- During the past five years, 6, 7, and 26 transit observations were carried out for the HAT-P-9b, HAT-P-32b, and HAT-P-36b systems, respectively, through the Transiting Exoplanet Monitoring Project network. Combined with the published photometric data and radial-velocity measurements, our new photometry allows us to revisit the system parameters and search for additional close-in planetary companions in these hot Jupiter systems. We measure an updated R_P_/R_*_=0.1260+/-0.0011 for HAT-P-36 system in the R band, which is 4.5{sigma} larger than the published i-band radius ratio of 0.1186+/-0.0012. We also perform a transit timing variation (TTV) analysis for each system. Because no significant TTVs were found, we place an upper mass limit on an additional planet for each system.
- ID:
- ivo://CDS.VizieR/J/ApJ/693/1084
- Title:
- Ten new and updated multiplanet systems
- Short Name:
- J/ApJ/693/1084
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the latest velocities for ten multiplanet systems, including a re-analysis of archival Keck and Lick data, resulting in improved velocities that supersede our previously published measurements. We derive updated orbital fits for 10 Lick and Keck systems, including two systems (HD 11964, HD 183263) for which we provide confirmation of second planets only tentatively identified elsewhere, and two others (HD 187123 and HD 217107) for which we provide a major revision of the outer planet's orbit. We compile orbital elements from the literature to generate a catalog of the 28 published multiple-planet systems around stars within 200pc.
- ID:
- ivo://CDS.VizieR/J/ApJ/809/8
- Title:
- Terrestrial planet occurrence rates for KOI stars
- Short Name:
- J/ApJ/809/8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure planet occurrence rates using the planet candidates discovered by the Q1-Q16 Kepler pipeline search. This study examines planet occurrence rates for the Kepler GK dwarf target sample for planet radii, 0.75<=Rp<=2.5R_{Earth}_, and orbital periods, 50<=Porb<=300days, with an emphasis on a thorough exploration and identification of the most important sources of systematic uncertainties. Integrating over this parameter space, we measure an occurrence rate of F_0_=0.77 planets per star, with an allowed range of 0.3<=F0<=1.9. The allowed range takes into account both statistical and systematic uncertainties, and values of F_0_ beyond the allowed range are significantly in disagreement with our analysis. We generally find higher planet occurrence rates and a steeper increase in planet occurrence rates toward small planets than previous studies of the Kepler GK dwarf sample. Through extrapolation, we find that the one year orbital period terrestrial planet occurrence rate {zeta}_1.0_=0.1, with an allowed range of 0.01<={zeta}_1.0_<=2, where {zeta}_1.0_ is defined as the number of planets per star within 20% of the Rp and Porb of Earth. For G dwarf hosts, the {zeta}_1.0_ parameter space is a subset of the larger {eta}_{Earth}_ parameter space, thus {zeta}_1.0_ places a lower limit on {eta}_{Earth}_ for G dwarf hosts. From our analysis, we identify the leading sources of systematics impacting Kepler occurrence rate determinations as reliability of the planet candidate sample, planet radii, pipeline completeness, and stellar parameters.
- ID:
- ivo://CDS.VizieR/J/A+A/648/A71
- Title:
- TESS optical phase curve of KELT-1b
- Short Name:
- J/A+A/648/A71
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the detection and analysis of the phase curve of KELT-1b at optical wavelengths, analyzing data taken by the Transiting Exoplanet Survey Satellite (TESS). The light curve shows variations due to ellipsoidal variations, Doppler beaming, transit and secondary eclipse of KELT-1, and phase curve variations of KELT-1b.
- ID:
- ivo://CDS.VizieR/J/A+A/633/A53
- Title:
- TESS planet candidates classification
- Short Name:
- J/A+A/633/A53
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Accurately and rapidly classifying exoplanet candidates from transit surveys is a goal of growing importance as the data rates from space-based survey missions increase. This is especially true for NASA's TESS mission which generates thousands of new candidates each month. Here we created the first deep learning model capable of classifying TESS planet candidates. We adapted the neural network model of Ansdell et al (2018) to TESS data. We then trained and tested this updated model on 4 sectors of high-fidelity, pixel-level simulations data created using the Lilith simulator & processed using the full TESS pipeline. With the caveat that direct transfer of the model to real data will not perform as accurately, we also applied this model to four sectors of TESS candidates. We find our model performs very well on our simulated data, with 97% average precision and 92% accuracy on planets in the 2-class model. This accuracy is also boosted by another ~4% if planets found at the wrong periods are included. We also performed 3- and 4-class classification of planets, blended & target eclipsing binaries, and non-astrophysical false positives, which have slightly lower average precision and planet accuracies, but are useful for follow-up decisions. When applied to real TESS data, 61% of Threshold Crossing Events (TCEs) coincident with currently published TOIs are recovered as planets, 4% more are suggested to be Eclipsing Binaries, and we propose a further 200 TCEs as planet candidates.
- ID:
- ivo://CDS.VizieR/J/PASP/131/C4401
- Title:
- TESS predicted yield of transits
- Short Name:
- J/PASP/131/C4401
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Radial velocity (RV) surveys have detected hundreds of exoplanets through their gravitational interactions with their host stars. Some will be transiting, but most lack sufficient follow-up observations to confidently detect (or rule out) transits. We use published stellar, orbital, and planetary parameters to estimate the transit probabilities for nearly all exoplanets that have been discovered via the RV method. From these probabilities, we predict that 25.5_-0.7_^+0.7^ of the known RV exoplanets should transit their host stars. This prediction is more than double the amount of RV exoplanets that are currently known to transit. The Transiting Exoplanet Survey Satellite (TESS) presents a valuable opportunity to explore the transiting nature of many of the known RV exoplanet systems. Based on the anticipated pointing of TESS during its two-year primary mission, we identify the known RV exoplanets that it will observe and predict that 11.7_-0.3_^+0.3^ of them will have transits detected by TESS. However, we only expect the discovery of transits for ~3 of these exoplanets to be novel (i.e., not previously known). We predict that the TESS photometry will yield dispositive null results for the transits of ~125 RV exoplanets. This will represent a substantial increase in the effort to refine ephemerides of known RV exoplanets. We demonstrate that these results are robust to changes in the ecliptic longitudes of future TESS observing sectors. Finally, we consider how several potential TESS extended mission scenarios affect the number of transiting RV exoplanets we expect TESS to observe.
- ID:
- ivo://CDS.VizieR/V/39
- Title:
- 4th Catalog of Orbits of Visual Binaries
- Short Name:
- V/39
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Finsen-Worley Catalog (1970), supplemented by all subsequently published orbits known to Worley and Heintz as of 1 July 1982 formed the basis for the present compilation. Practically all stars having visual orbits were reobserved in the preceding decade, often repeatedly either with micrometers or with speckle interferometers. Astrometric solutions are included but only if they were judged to be relatively certain. Orbits with period greater than 4000 years and hyperbolic orbits were rejected as being unreliable. The catalog contains 928 orbits of 847 systems (counting triples as two systems). There are 23 orbits of unresolved systems. The catalog contains for each system the names of the star and the components involved, the 1900 position, the ADS number, the magnitude and spectral type for each component, the orbital elements, the equinox of the node, the quality of the orbit, the date of the last observation, the inclusive dates for which an ephemeris is given by the author, the computer of the orbit, and a reference.
