- ID:
- ivo://CDS.VizieR/J/AJ/158/109
- Title:
- Occurrence rates of planets orbiting FGK stars
- Short Name:
- J/AJ/158/109
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We characterize the occurrence rate of planets, ranging in size from 0.5 to 16 R_{Earth}_, orbiting FGK stars with orbital periods from 0.5 to 500 days. Our analysis is based on results from the "DR25" catalog of planet candidates produced by NASA's Kepler mission and stellar radii from Gaia "DR2" (Cat. I/345). We incorporate additional Kepler data products to accurately characterize the efficiency of planets being recognized as "threshold crossing events" by Kepler's Transiting Planet Search pipeline and labeled as planet candidates by the robovetter. Using a hierarchical Bayesian model, we derive planet occurrence rates for a wide range of planet sizes and orbital periods. For planets with sizes 0.75-1.5 R_{Earth}_ and orbital periods of 237-500 days, we find a rate of planets per FGK star of <0.27 (84.13th percentile). While the true rate of such planets could be lower by a factor of ~2 (primarily due to potential contamination of planet candidates by false alarms), the upper limits on the occurrence rate of such planets are robust to ~10%. We recommend that mission concepts aiming to characterize potentially rocky planets in or near the habitable zone of Sun-like stars prepare compelling science programs that would be robust for a true rate in the range f_R,P_=0.03-0.40 for 0.75-1.5 R_{Earth}_ planets with orbital periods in 237-500 days, or a differential rate of {Gamma}_{Earth}_=(d^2^f)/[d(lnP)d(lnR_p_)]=0.06-0.76.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/160/235
- Title:
- Optical photometry and RVs of TOI-481b and TOI-892b
- Short Name:
- J/AJ/160/235
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481b and TOI-892b have similar radii (0.99{+/-}0.01R_Jup_ and 1.07{+/-}0.02R_Jup_, respectively), and orbital periods (10.3311days and 10.6266days, respectively), but significantly different masses (1.53{+/-}0.03M_Jup versus 0.95{+/-}0.07M_Jup_, respectively). Both planets orbit metal-rich stars ([Fe/H]=+0.26{+/-}0.05dex and [Fe/H]=+0.24{+/-}0.05 for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a M_*_=1.14{+/-}0.02M_{odot}_, R_*_=1.66{+/-}0.02R_{odot}_ G-type star (Teff=5735{+/-}72K), that with an age of 6.7Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (Teff=6261{+/-}80K), which has a mass of M_*_=1.28{+/-}0.03M_{odot}_ and a radius of R_*_=1.39{+/-}0.02R_{odot}_. TOI-481b and TOI-892b join the scarcely populated region of transiting gas giants with orbital periods longer than 10days, which is important to constrain theories of the formation and structure of hot Jupiters.
- ID:
- ivo://CDS.VizieR/J/A+A/587/A51
- Title:
- Overlooked wide companions of nearby F stars
- Short Name:
- J/A+A/587/A51
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We checked a sample of 545 F stars within 50pc for wide companions using existing near-infrared and optical sky surveys.
- ID:
- ivo://CDS.VizieR/J/A+A/574/A17
- Title:
- Period spacings in gamma Dor stars
- Short Name:
- J/A+A/574/A17
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The analysis of stellar oscillations is one of the most reliable ways to probe stellar interiors. Recent space missions such as Kepler have provided us with an opportunity to study these oscillations with unprecedented detail. For many multi-periodic pulsators such as gamma Doradus stars, this led to the detection of dozens to hundreds of oscillation frequencies that could not be found from ground-based observations. We aim to detect non-uniform period spacings in the Fourier spectra of a sample of gamma Doradus stars observed by Kepler. Such detection is complicated by both the large number of significant frequencies in the space photometry and by overlapping non-equidistant rotationally split multiplets. Guided by theoretical properties of gravity-mode oscillation of gamma Doradus stars, we developed a period-spacing detection method and applied it to Kepler observations of a few stars, after having tested the performance from simulations. The application of the technique resulted in the clear detection of non-uniform period spacing series for three out of the five treated Kepler targets. Disadvantages of the technique are also discussed, and include the disability to distinguish between different values of the spherical degree and azimuthal order of the oscillation modes, without additional theoretical modelling. Despite the shortcomings, the method is shown to enable solid detections of period spacings for gamma Doradus stars, which will allow future asteroseismic analyses of these stars.
- ID:
- ivo://CDS.VizieR/III/169A
- Title:
- Photometric Atlas of Procyon for 314-747 nm
- Short Name:
- III/169A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This atlas contains intensities, expressed in terms of the continuum as 100, in steps of 5 milli Angstroem of the F5 star Procyon. The spectral range is from 3140 to 7469.995 Angstroems.
- ID:
- ivo://CDS.VizieR/J/AJ/150/85
- Title:
- Photometry and spectroscopy of HAT-P-56
- Short Name:
- J/AJ/150/85
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of HAT-P-56b by the HATNet survey, an inflated hot Jupiter transiting a bright F-type star in Field 0 of NASA's K2 mission. We combine ground-based discovery and follow-up light curves with high precision photometry from K2, as well as ground-based radial velocities from the Tillinghast Reflector Echelle Spectrograph on the Fred Lawrence Whipple Observatory 1.5m telescope to determine the physical properties of this system. HAT-P-56b has a mass of 2.18M_J_, radius of 1.47R_J_, and transits its host star on a near-grazing orbit with a period of 2.7908day. The radius of HAT-P-56b is among the largest known for a planet with M_P_>2M_J_. The host star has a V-band magnitude of 10.9, mass of 1.30M_{sun}_, and radius of 1.43R_{sun}_. The periodogram of the K2 light curve suggests that the star is a {gamma} Dor variable. HAT-P-56b is an example of a ground-based discovery of a transiting planet, where space-based observations greatly improve the confidence in the confirmation of its planetary nature, and also improve the accuracy of the planetary parameters.
- ID:
- ivo://CDS.VizieR/J/AJ/147/84
- Title:
- Photometry and spectroscopy of HAT-P-49
- Short Name:
- J/AJ/147/84
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the discovery of the transiting extrasolar planet HAT-P-49b. The planet transits the bright (V=10.3) slightly evolved F-star HD340099 with a mass of 1.54M_{Sun}_ and a radius of 1.83R_{Sun}_. HAT-P-49b is orbiting one of the 25 brightest stars to host a transiting planet which makes this a favorable candidate for detailed follow-up. This system is an especially strong target for Rossiter-McLaughlin follow-up due to the host star's fast rotation, 16km/s. The planetary companion has a period of 2.6915 days, mass of 1.73M_J_, and radius of 1.41R_J_. The planetary characteristics are consistent with that of a classical hot Jupiter but we note that this is the fourth most massive star to host a transiting planet with both M_p_ and R_p_ well determined.
- ID:
- ivo://CDS.VizieR/J/MNRAS/419/2844
- Title:
- Radial metallicity gradient from RAVE DR3
- Short Name:
- J/MNRAS/419/2844
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We investigate radial metallicity gradients for a sample of dwarf stars from the RAdial Velocity Experiment (RAVE) Data Release 3 (DR3, Cat. III/265). We select a total of approximately 17000 F-type and G-type dwarfs, using a selection of colour, log g and uncertainty in the derived space motion, and calculate for each star a probabilistic (kinematic) population assignment to a thick or thin disc using space motion and additionally another (dynamical) assignment using stellar vertical orbital eccentricity. We additionally subsample by colour, to provide samples biased toward young thin-disc and older thin-disc stars. We derive a metallicity gradient as a function of Galactocentric radial distance, i.e. d[M/H]/dRm=-0.051+/-0.005dex/kpc, for the youngest sample, F-type stars with vertical orbital eccentricities e_v_<=0.04. Samples biased toward older thin-disc stars show systematically shallower abundance gradients.
- ID:
- ivo://CDS.VizieR/J/AJ/158/197
- Title:
- Radial velocities & light curves of KELT-24
- Short Name:
- J/AJ/158/197
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of KELT-24 b, a massive hot Jupiter orbiting a bright (V=8.3 mag, K=7.2 mag) young F-star with a period of 5.6 days. The host star, KELT-24 (HD 93148), has a T_eff_=6509_-49_^+50^ K, a mass of M_*_=1.460_-0.059_^+0.055^ M_{sun}_, a radius of R_*_=1.506+/-0.022 R_{sun}_, and an age of 0.78_-0.42_^+0.61^ Gyr. Its planetary companion (KELT-24 b) has a radius of R_P_=1.272+/-0.021 R_J_ and a mass of M_P_=5.18_-0.22_^+0.21^ M_J_, and from Doppler tomographic observations, we find that the planet's orbit is well-aligned to its host star's projected spin axis ({lambda}=2.6_-3.6_^+5.1^). The young age estimated for KELT-24 suggests that it only recently started to evolve from the zero-age main sequence. KELT-24 is the brightest star known to host a transiting giant planet with a period between 5 and 10 days. Although the circularization timescale is much longer than the age of the system, we do not detect a large eccentricity or significant misalignment that is expected from dynamical migration. The brightness of its host star and its moderate surface gravity make KELT-24b an intriguing target for detailed atmospheric characterization through spectroscopic emission measurements since it would bridge the current literature results that have primarily focused on lower mass hot Jupiters and a few brown dwarfs.
- ID:
- ivo://CDS.VizieR/J/ApJ/813/89
- Title:
- Radial velocities of Milky Way inner halo stars
- Short Name:
- J/ApJ/813/89
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We measure the three components of velocity dispersion, {sigma}_R_, {sigma}_{theta}_, {sigma}_{phi}_, for stars within 6<R<30kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with previously published data so that we can more finely sample the stellar halo. We use a maximum likelihood statistical method for estimating mean velocities, dispersions, and covariances assuming only that velocities are normally distributed. The alignment of the velocity ellipsoid is consistent with a spherically symmetric gravitational potential. From the spherical Jeans equation, the mass of the Milky Way is M(R<=12kpc)=1.3x10^11^M_{sun}_ with an uncertainty of 40%. We also find a region of discontinuity, 15<~R<~25kpc, where the estimated velocity dispersions and anisotropies diverge from their anticipated values, confirming the break observed by others. We argue that this break in anisotropy is physically explained by coherent stellar velocity structure in the halo, such as the Sgr stream. To significantly improve our understanding of halo kinematics will require combining radial velocities with future Gaia proper motions.
