Evidence of Three Mechanisms Explaining the Radius Anomaly of Hot Jupiters

The radii of hot Jupiters are still not fully understood and all of the proposed explanations are based on the idea that these close-in giant planets possess hot interiors. We approach the radius anomaly problem by adopting a statistical approach. We infer the internal luminosity for the sample of hot Jupiters, study its effect on the interior structure, and put constraints on which mechanism is the dominant one. We develop a flexible and robust hierarchical Bayesian model that couples the interior structure of exoplanets to their observed properties. We apply the model to 314 hot Jupiters and infer the internal luminosity distribution for each planet and study at the population level ({\it i}) the mass-luminosity-radius distribution and as a function of equilibrium temperature the distributions of the ({\it ii}) heating efficiency, ({\it iii}) internal temperature, and the ({\it iv}) pressure of the radiative-convective-boundary (RCB). We find that hot Jupiters tend to have high internal luminosity leading to hot interiors. This has important consequences on the cooling rate and we find that the RCB is located at low pressures. Assuming that the ultimate source of the extra heating is the irradiation from the host star, we illustrate that the heating efficiency follows a Gaussian distribution, in agreement with previous results. We discuss our findings in the context of the proposed heating mechanisms and illustrate that ohmic dissipation, advection of potential temperature, and thermal tides are in agreement with certain trends inferred from our analysis and thus all three models can explain aspects of the observations. We provide new insights on the interior structure of hot Jupiters and show that with our current knowledge it is still challenging to firmly identify the universal mechanism driving the inflated radii.Comment: 27 pages and 12 figures. Accepted in A&A. Source code can be found at https://github.com/psarkis/bloatedHJs and data at https://www.space.unibe.ch/research/research_groups/planets_in_time/numerical_data/index_eng.htm

EPIC247098361b: a transiting warm Saturn on an eccentric P=11.2P=11.2 days orbit around a V=9.9V=9.9 star

We report the discovery of EPIC247098361b using photometric data of the Kepler K2 satellite coupled with ground-based spectroscopic observations. EPIC247098361b has a mass of M$_{P}=0.397\pm 0.037$ M$_J$, a radius of R$_{P}=1.00 \pm 0.020$ R$_J$, and a moderately low equilibrium temperature of $T_{eq}=1030 \pm 15$ K due to its relatively large star-planet separation of $a=0.1036$ AU. EPIC247098361b orbits its bright ($V=9.9$) late F-type host star in an eccentric orbit ($e=0.258 \pm 0.025$) every 11.2 days, and is one of only four well characterized warm Jupiters having hosts stars brighter than $V=10$. We estimate a heavy element content of 20 $\pm$ 7 M$_{\oplus}$ for EPIC247098361b, which is consistent with standard models of giant planet formation. The bright host star of EPIC247098361b makes this system a well suited target for detailed follow-up observations that will aid in the study of the atmospheres and orbital evolution of giant planets at moderate separations from their host stars.Comment: 11 pages, 10 figures, submitted to MNRA

New HARPS and FEROS observations of GJ1046

In this paper we present new precise Doppler data of GJ1046 taken between November 2005 and July 2018 with the HARPS and the FEROS high-resolution spectographs. In addition, we provide a new stellar mass estimate of GJ1046 and we update the orbital parameters of the GJ1046 system. These new data and analysis could be used together with the GAIA epoch astrometry, when available, for braking the $\sin i$ degeneracy and revealing the true mass of the GJ1046 system.Comment: 2 pages, 1 figure, 1 table with RV data (available only in the Astro-PH version of the paper), Accepted by RNAA

Production of Acalypha wilkesiana seedlings using stem cuttings

The objective of this work was to evaluate the rooting of cuttings of Acalifa (Acalypha Wilkesiana) with different concentrations of indolbutyric acid (IBA). The matrix plant from which the cuttings were taken, is planted as a hedge and located at the biology institute of the Federal Rural University of Rio de Janeiro in the city of Seropédica-RJ. The experimental design was completely randomized, in a 3x3 factorial, with three different concentrations of IBA (0, 1000 and 2000 mg L-1 or 0, 2000 and 4000 mg L-1 for 15 seconds) and three types of cuttings (herbaceous, semi-woody and woody), with three replications and ten cuttings per plot. The experiments were carried out at two different times, namely: autumn and winter / spring. The following were evaluated: percentage of live cuttings, rooted, with callus and sprouting, number of roots per cut, length of the largest root. Acalypha wilkesiana can be propagated by stem cuttings, whether woody, semi-woody or herbaceous cuttings. However, herbaceous cuttings have a lower percentage of survival and rooting. Also, is a species of easy rooting through cutting of stems, dispensing with the use of AIB. Stems collected in the autumn period yield greater efficiency and productivity in the propagation of cuttings by cuttings.The objective of this work was to evaluate the rooting of cuttings of Acalifa (Acalypha Wilkesiana) with different concentrations of indolbutyric acid (IBA). The matrix plant from which the cuttings were taken, is planted as a hedge and located at the biology institute of the Federal Rural University of Rio de Janeiro in the city of Seropédica-RJ. The experimental design was completely randomized, in a 3x3 factorial, with three different concentrations of IBA (0, 1000 and 2000 mg L-1 or 0, 2000 and 4000 mg L-1 for 15 seconds) and three types of cuttings (herbaceous, semi-woody and woody), with three replications and ten cuttings per plot. The experiments were carried out at two different times, namely: autumn and winter / spring. The following were evaluated: percentage of live cuttings, rooted, with callus and sprouting, number of roots per cut, length of the largest root. Acalypha wilkesiana can be propagated by stem cuttings, whether woody, semi-woody or herbaceous cuttings. However, herbaceous cuttings have a lower percentage of survival and rooting. Also, is a species of easy rooting through cutting of stems, dispensing with the use of AIB. Stems collected in the autumn period yield greater efficiency and productivity in the propagation of cuttings by cuttings

Aumento na expressão gênica das nucleotidases cerebrais de ratos epilépticos tratados com drogas anticonvulsivantes

23

Citotoxidade do ATP extracelular em fatias organotípicas de hipocampo de ratos e linhagens de gliomas

42