- ID:
- ivo://CDS.VizieR/J/ApJ/743/184
- Title:
- Pan-Pacific Planet Search (PPPS) I. 7 CMa
- Short Name:
- J/ApJ/743/184
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We introduce the Pan-Pacific Planet Search, a survey of 170 metal-rich Southern Hemisphere subgiants using the 3.9m Anglo-Australian Telescope. We report the first discovery from this program, a giant planet orbiting 7 CMa (HD 47205) with a period of 763+/-17 days, eccentricity e=0.14+/-0.06, and msin i=2.6+/-0.6M_Jup_. The host star is a K giant with a mass of 1.5+/-0.3M_{sun}_ and metallicity [Fe/H]=0.21+/-0.10. The mass and period of 7 CMa b are typical of planets which have been found to orbit intermediate-mass stars (M_*_>1.3M_{sun}_). Hipparcos photometry shows this star to be stable to 0.0004 mag on the radial-velocity period, giving confidence that this signal can be attributed to reflex motion caused by an orbiting planet.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/455/4212
- Title:
- Pan-STARRS 1: occurrence in the Kepler field
- Short Name:
- J/MNRAS/455/4212
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The NASA Kepler mission has revolutionized time-domain astronomy and has massively expanded the number of known extrasolar planets. However, the effect of wide multiplicity on exoplanet occurrence has not been tested with this data set. We present a sample of 401 wide multiple systems containing at least one Kepler target star. Our method uses Pan-STARRS 1 and archival data to produce an accurate proper motion catalogue of the Kepler field. Combined with Pan-STARRS 1 SED fits and archival proper motions for bright stars, we use a newly developed probabilistic algorithm to identify likely wide binary pairs which are not chance associations. As byproducts of this we present stellar SED templates in the Pan-STARRS 1 photometric system and conversions from this system to Kepler magnitudes. We find that Kepler target stars in our binary sample with separations above 6arcsec are no more or less likely to be identified as confirmed or candidate planet hosts than a weighted comparison sample of Kepler targets of similar brightness and spectral type. Therefore we find no evidence that binaries with projected separations greater than 3000au affect the occurrence rate of planets with P<300d around FGK stars.
- ID:
- ivo://CDS.VizieR/J/ApJS/218/26
- Title:
- Parameters of planets orbiting coolest dwarfs
- Short Name:
- J/ApJS/218/26
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The coolest dwarf stars targeted by the Kepler Mission constitute a relatively small but scientifically valuable subset of the Kepler target stars, and provide a high-fidelity, nearby sample of transiting planetary systems. Using archival Kepler data spanning the entire primary mission, we perform a uniform analysis to extract, confirm, and characterize the transit signals discovered by the Kepler pipeline toward M-type dwarf stars. We recover all but two of the signals reported in a recent listing from the Exoplanet Archive resulting in 163 planet candidates associated with a sample of 104 low-mass stars. We fitted the observed light curves to transit models using a Markov Chain Monte Carlo method and we have made the posterior samples publicly available to facilitate further studies. We fitted empirical transit times to individual transit signals with significantly non-linear ephemerides for accurate recovery of transit parameters and precise measuring of transit timing variations. We also provide the physical parameters for the stellar sample, including new measurements of stellar rotation, allowing the conversion of transit parameters into planet radii and orbital parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/689/L149
- Title:
- Parameter variations of Gliese 436b transits
- Short Name:
- J/ApJ/689/L149
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present ground-based observations of the transiting Neptune-mass planet Gl 436b obtained with the 3.5m telescope at Apache Point Observatory and other supporting telescopes. Included in this is an observed transit in early 2005, over 2 years before the earliest reported transit detection. We have compiled all available transit data to date and perform a uniform modeling using the JKTEBOP code. We do not detect any transit timing variations of amplitude greater than ~1 minute over the ~3.3 year baseline. We do however find possible evidence for a self-consistent trend of increasing orbital inclination, transit width, and transit depth, which supports the supposition that Gl 436b is being perturbed by another planet of <~12M_{earth}_ in a nonresonant orbit.
- ID:
- ivo://CDS.VizieR/J/MNRAS/446/1020
- Title:
- Parent stars of extrasolar planets. XIV.
- Short Name:
- J/MNRAS/446/1020
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the results of our analysis of new high-resolution spectra of 30 late-F to early-G dwarf field stars for the purpose of deriving their Li abundances. They were selected from the subsample of stars in the Valenti and Fischer compilation that are lacking detected planets. These new data serve to expand our comparison sample used to test whether stars with Doppler-detected giant planets display Li abundance anomalies. Our results continue to show that Li is deficient among stars with planets when compared to very similar stars that lack such planets. This conclusion is strengthened when we add literature data to ours in a consistent way. We present a table of stars with planets paired with very similar stars lacking planets, extending the recent similar results of Delgado Mena et al. (2014A&A...562A..92D, Cat. J/A+A/562/A92).
- ID:
- ivo://CDS.VizieR/J/ApJ/808/194
- Title:
- Performance of exoplanet search space missions
- Short Name:
- J/ApJ/808/194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analytic model to estimate the capabilities of space missions dedicated to the search for biosignatures in the atmosphere of rocky planets located in the habitable zone of nearby stars. Relations between performance and mission parameters, such as mirror diameter, distance to targets, and radius of planets, are obtained. Two types of instruments are considered: coronagraphs observing in the visible, and nulling interferometers in the thermal infrared. Missions considered are: single-pupil coronagraphs with a 2.4m primary mirror, and formation-flying interferometers with 4x0.75m collecting mirrors. The numbers of accessible planets are calculated as a function of {eta}_Earth_. When Kepler gives its final estimation for {eta}_Earth_, the model will permit a precise assessment of the potential of each instrument. Based on current estimations, {eta}_Earth_=10% around FGK stars and 50% around M stars, the coronagraph could study in spectroscopy only ~1.5 relevant planets, and the interferometer ~14.0. These numbers are obtained under the major hypothesis that the exozodiacal light around the target stars is low enough for each instrument. In both cases, a prior detection of planets is assumed and a target list established. For the long-term future, building both types of spectroscopic instruments, and using them on the same targets, will be the optimal solution because they provide complementary information. But as a first affordable space mission, the interferometer looks the more promising in terms of biosignature harvest.
- ID:
- ivo://CDS.VizieR/J/A+A/602/A117
- Title:
- Periods of 2290 CoRoT binaries
- Short Name:
- J/A+A/602/A117
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The CoRoT mission during its flight-phase 2007-2012 delivered the light-curves for over 2000 eclipsing binaries. Data from the Kepler mission have proven the existence of several transiting circumbinary planets. Albeit light-curves from CoRoT have typically lower precision and shorter coverage, CoRoT's number of targets is similar to Kepler, and some of the known circumbinary planets could potentially be detected in CoRoT data as well. The aim of this work has been a revision of the entire CoRoT data-set for the presence of circumbinary planets, and the derivation of limits to the abundances of such planets. We developed a code which removes the light curve of the eclipsing binaries and searches for quasi-periodic transit-like features in a light curve after removal of binary eclipses and instrumental features. The code needs little information on the sample systems and can be used for other space missions as well, like Kepler, K2, TESS and PLATO. The code is broad in the requirements leading to detections, but was tuned to deliver an amount of detections that is manageable in a subsequent, mainly visual, revision about their nature. In the CoRoT sample we identified three planet candidates whose transits would have arisen from a single pass across the central binary. No candidates remained however with transit events from multiple planetary orbits. We calculated the upper limits for the number of Jupiter, Saturn and Neptune sized planets in co-planar orbits for different orbital period ranges. We found that there are much less giant planets in short-periodic orbits around close binary systems than around single stars.
- ID:
- ivo://CDS.VizieR/J/A+A/454/379
- Title:
- 2003-2004 Phoebe CCD astrometry
- Short Name:
- J/A+A/454/379
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In 2003-2004, we obtained 115 new observations of Phoebe, the 9th Saturnian faint satellite (visual magnitude of about 16.5). We used a large CCD detector (2048 x2048 pixels) mounted on the 1.56m astrometric reflector at the Sheshan Station, near Shanghai. In our reduction, an up-to-date catalogue of stars, UCAC2 (Zacharias et al., 2004, Cat. <I/289>), was chosen to ensure a proper astrometric calibration. A comparison of our observations to three recently available, high quality ephemerides, including the JPL SAT185 by Jacobson (SAT185, JPL satellite ephemeris), has shown that most of our observed positions of Phoebe present an accuracy of some tens of mas, which appears to be a very high level for such a faint satellite.
- ID:
- ivo://CDS.VizieR/J/A+A/643/L10
- Title:
- Phoebe Spherical Harmonics decomposition
- Short Name:
- J/A+A/643/L10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Phoebe is an irregular satellite of Saturn, and its origin, from either between the orbits of the giant planets or the Kuiper Belt, is still uncertain. The extent of differentiation of its interior can potentially help inform its formation location because it is mainly determined by heat from 26-aluminium. The internal structure is reflected in the shape, assuming the body is relaxed to hydrostatic equilibrium. Although previous data analysis indicates Phoebe is close to hydrostatic equilibrium, its heavily cratered surface makes it difficult to tease out its low-order shape characteristics. This paper aims to extract Phoebe's global shape from the observations returned by the Cassini mission for comparison with uniform and stratified interior models under the assumption of hydrostatic equilibrium. The global shape is derived from fitting spherical harmonics and keeping only the low-degree harmonics that represent the shape underneath the heavily cratered surface. The hydrostatic theoretical model for shape interpretation is based on the Clairaut equation developed to the third order (although the second order is sufficient in this case). We show that Phoebe is differentiated with a mantle density between 1900 and 2400kg/m^3^. The presence of a porous surface layer further restricts the fit with the observed shape. This result confirms the earlier suggestion that Phoebe accreted with sufficient 26-aluminium to drive at least partial differentiation, favoring an origin with C-type asteroids.
- ID:
- ivo://CDS.VizieR/J/ApJ/745/77
- Title:
- Photochemical model for planet WASP-12b
- Short Name:
- J/ApJ/745/77
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The hot-Jupiter WASP-12b is a heavily irradiated exoplanet in a short-period orbit around a G0-star with twice the metallicity of the Sun. A recent thermochemical equilibrium analysis based on Spitzer and ground-based infrared observations suggests that the presence of CH_4_ in its atmosphere and the lack of H_2_O features can only be explained if the carbon-to-oxygen ratio in the planet's atmosphere is much greater than the solar ratio ([C]/[O]=0.54). Here, we use a one-dimensional photochemical model to study the effect of disequilibrium chemistry on the observed abundances of H_2_O, CO, CO_2_, and CH_4_ in the WASP-12b atmosphere. We consider two cases: one with solar [C]/[O] and another with [C]/[O]=1.08. The solar case predicts that H_2_ O and CO are more abundant than CO_2_ and CH_4_, as expected, whereas the high [C]/[O] model shows that CO, C_2_H_2_, and HCN are more abundant. This indicates that the extra carbon from the high [C]/[O] model is in hydrocarbon species. H_2_ O photolysis is the dominant disequilibrium mechanism that alters the chemistry at higher altitudes in the solar [C]/[O] case, whereas photodissociation of C_2_H_2_ and HCN is significant in the super-solar case. Furthermore, our analysis indicates that C_2_H_2_ is the major absorber in the atmosphere of WASP-12b and the absorption features detected near 1.6 and 8{mu}m may be arising from C_2_H_2_ rather than CH_4_. The Hubble Space Telescope's WFC3 can resolve this discrepancy, as C_2_H_2_ has absorption between 1.51 and 1.54{mu}m, while CH_4_ does not.