20 research outputs found

    Dynamical masses of two young transiting sub-Neptunes orbiting HD 63433

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    Although the number of exoplanets reported in the literature exceeds 5000 so far, only a few dozen of them are young planets (\le900 Myr). However, a complete characterization of these young planets is key to understanding the current properties of the entire population. Hence, it is necessary to constrain the planetary formation processes and the timescales of dynamical evolution by measuring the masses of exoplanets transiting young stars. We characterize and measure the masses of two transiting planets orbiting the 400 Myr old solar-type star HD\,63433, which is a member of the Ursa Major moving group. We analysed precise photometric light curves of five sectors of the TESS mission with a baseline of \sim750 days and obtained \sim150 precise radial velocity measurements with the visible and infrared arms of the CARMENES instrument at the Calar Alto 3.5 m telescope in two different campaigns of \sim500 days. We performed a combined photometric and spectroscopic analysis to retrieve the planetary properties of two young planets. The strong stellar activity signal was modelled by Gaussian regression processes. We have updated the transit parameters of HD\,63433\,b and c and obtained planet radii of Rpb_p^b\,=\,2.140\,±\pm\,0.087 R_\oplus and Rpc_p^c\,=\,2.692\,±\pm\,0.108 R_\oplus. Our analysis allowed us to determine the dynamical mass of the outer planet with a 4σ\sigma significance (MpcM_p^c\,=\,15.54\,±\pm\,3.86 M_\oplus) and set an upper limit on the mass of the inner planet at 3σ\sigma (MpbM_p^b\,<<\,21.76 M_\oplus). According to theoretical models, both planets are expected to be sub-Neptunes, whose interiors mostly consist of silicates and water with no dominant composition of iron, and whose gas envelopes are lower than 2\% in the case of HD\,63433\,c. The envelope is unconstrained in HD\,63433\,b

    TOI-1135 b: A young hot Saturn-size planet orbiting a solar-type star

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    Despite the thousands of planets in orbit around stars known to date, the mechanisms of planetary formation, migration, and atmospheric loss remain unresolved. In this work, we confirm the planetary nature of a young Saturn-size planet transiting a solar-type star every 8.03 d, TOI-1135\,b. The age of the parent star is estimated to be in the interval of 125--1000 Myr based on various activity and age indicators, including its stellar rotation period of 5.13\,±\pm\,0.27 d and the intensity of photospheric lithium. We obtained follow-up photometry and spectroscopy, including precise radial velocity measurements using the CARMENES spectrograph, which together with the TESS data allowed us to fully characterise the parent star and its planet. As expected for its youth, the star is rather active and shows strong photometric and spectroscopic variability correlating with its rotation period. We modelled the stellar variability using Gaussian process regression. We measured the planetary radius at 9.02\,±\pm\,0.23 R_\oplus (0.81\,±\pm\,0.02 RJup_{\mathrm{Jup}}) and determined a 3σ\sigma upper limit of <<\,51.4 M_\oplus (<<\,0.16 \,MJup_{\rm{Jup}}) on the planetary mass by adopting a circular orbit. Our results indicate that TOI-1135\,b is an inflated planet less massive than Saturn or Jupiter but with a similar radius, which could be in the process of losing its atmosphere by photoevaporation. This new young planet occupies a region of the mass-radius diagram where older planets are scarse, and it could be very helpful to understanding the lower frequency of planets with sizes between Neptune and Saturn.Comment: Accepted in A&A. 18 pages, 15 figure

    Photometric follow-up of the 20 Myr-old multi-planet host star V1298~Tau with CHEOPS and ground-based telescopes

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    V1298 Tau hosts at least four planets. Since its discovery, this system has been a target of intensive photometric and spectroscopic monitoring. The characterisation of its architecture and planets' fundamental properties turned out to be very challenging so far. The determination of the orbital ephemeris of the outermost planet V1298 Tau ee remains an open question. Only two transits have been detected so far by Kepler/K2Kepler/K2 and TESS, allowing for a grid of reference periods to be tested with new observations, without excluding the possibility of transit timing variations. Observing a third transit would allow to better constrain the orbital period, and would also help determining an accurate radius of V1298 Tau ee because the former transits showed different depths. We observed V1298 Tau with the CHEOPS space telescope to search for a third transit of planet ee within observing windows that have been selected in order to test three of the shortest predicted orbital periods. We also collected ground-based observations to verify the result found with CHEOPS. We reanalysed Kepler/K2Kepler/K2 and TESS light curves to test how the results derived from these data are affected by alternative photometric extraction and detrending methods. We report the detection with CHEOPS of a transit that could be attributed to V1298 Tau ee. If so, that result implies that the orbital period calculated from fitting a linear ephemeris to the three available transits is close to 45\sim45 days. Results from the ground-based follow-up marginally support this possibility. We found that i\textit{i}) the transit observed by CHEOPS has a longer duration compared to that of the transits observed by Kepler/K2Kepler/K2 and TESS; ii\textit{ii}) the transit observed by TESS is >30%>30\% deeper than that of Kepler/K2Kepler/K2 and CHEOPS, and deeper than the measurement previously reported in the literature, according to our reanalysis.Comment: Accepted for publication on A&A. The abstract has been edited to fulfill the arXiv requirement

    Confirmation of an He I evaporating atmosphere around the 650-Myr-old sub-Neptune HD235088 b (TOI-1430 b) with CARMENES

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    HD235088 (TOI-1430) is a young star known to host a sub-Neptune-sized planet candidate. We validated the planetary nature of HD235088 b with multiband photometry, refined its planetary parameters, and obtained a new age estimate of the host star, placing it at 600-800 Myr. Previous spectroscopic observations of a single transit detected an excess absorption of He I coincident in time with the planet candidate transit. Here, we confirm the presence of He I in the atmosphere of HD235088 b with one transit observed with CARMENES. We also detected hints of variability in the strength of the helium signal, with an absorption of -0.91±\pm0.11%, which is slightly deeper (2σ\sigma) than the previous measurement. Furthermore, we simulated the He I signal with a spherically symmetric 1D hydrodynamic model, finding that the upper atmosphere of HD235088 b escapes hydrodynamically with a significant mass loss rate of (1.5-5) ×\times1010^{10}g s1^{-1}, in a relatively cold outflow, with TT=3125±\pm375 K, in the photon-limited escape regime. HD235088 b (RpR_{p} = 2.045±\pm0.075 R_{\oplus}) is the smallest planet found to date with a solid atmospheric detection - not just of He I but any other atom or molecule. This positions it a benchmark planet for further analyses of evolving young sub-Neptune atmospheres.Comment: Accepted for publication in A&A. 17 pages, 18 figure

    TOI-1801 b: A temperate mini-Neptune around a young M0.5 dwarf

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    Mallorquín, M., et al.We report the discovery, mass, and radius determination of TOI-1801 b, a temperate mini-Neptune around a young M dwarf. TOI-1801 b was observed in TESS sectors 22 and 49, and the alert that this was a TESS planet candidate with a period of 21.3 days went out in April 2020. However, ground-based follow-up observations, including seeing-limited photometry in and outside transit together with precise radial velocity (RV) measurements with CARMENES and HIRES revealed that the true period of the planet is 10.6 days. These observations also allowed us to retrieve a mass of 5.74 ± 1.46 M⊕, which together with a radius of 2.08 ± 0.12 R⊕, means that TOI-1801 b is most probably composed of water and rock, with an upper limit of 2% by mass of H2 in its atmosphere. The stellar rotation period of 16 days is readily detectable in our RV time series and in the ground-based photometry. We derived a likely age of 600–800 Myr for the parent star TOI-1801, which means that TOI-1801 b is the least massive young mini-Neptune with precise mass and radius determinations. Our results suggest that if TOI-1801 b had a larger atmosphere in the past, it must have been removed by some evolutionary mechanism on timescales shorter than 1 Gyr.This work is partly financed by the Spanish Ministry of Economics and Competitiveness through projects PGC2018-098153-B-C31, PID2019-109522GB-C5[1:4]. E. G. acknowledges the generous support from the Deutsche Forschungsgemeinschaft (DFG) of the grant HA3279/14-1. P.D. acknowledges support from a 51 Pegasi b Postdoctoral Fellowship from the Heising-Simons Foundation. D.H. acknowledges support from the Alfred P. Sloan Foundation, the National Aeronautics and Space Administration (80NSSC21K0652) and the Australian Research Council (FT200100871). This work is partly supported by JSPS KAKENHI Grant Numbers JP18H05439 and JST CREST Grant Number JPMJCR176.Peer reviewe

    El huerto y la fuente, remodelación de espacios

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    El trabajo tiene como finalidad incorporar al patio de recreo de la Casa de los Niños dos nuevos elementos que permiten a los alumnos ampliar su campo de experiencias: la fuente y el huerto. Los objetivos son: posibilitar al niño el acercamiento, contacto y conocimiento de la naturaleza; inculcar en ellos el respeto hacia el medio; y potenciar el proceso de aprendizaje de cada niño al proporcionarle un espacio y unos materiales para jugar, explorar, observar, comparar y descubrir su entorno más inmediato. En el desarrollo de la experiencia, y una vez que los nuevos materiales ya están incorporados al jardín del centro, se emprenden actividades como: juegos manipulativos, mezclas de tintes con agua, comprobación de los cambios físicos del agua, etc. En el huerto, con la ayuda y asesoramiento de los padres, se comienza a cultivar productos de temporada. También se trabaja de forma globalizada, se desarrollan aspectos lingüísticos, psicomotores, afectivos, cognitivos y de autonomía personal. Para desarrollar la socialización se realizan actividades en grupo basadas en el aprendizaje de normas de convivencia, participación, etc. El proceso de evaluación es continuo, sistemático y flexible, adaptado a las diferencias individuales de cada niño y a sus intereses y capacidades y se basa, fundamentalmente, en la observación directa del alumno.Madrid (Comunidad Autónoma). Consejería de Educación y CulturaMadridMadrid (Comunidad Autónoma). Subdirección General de Formación del Profesorado. CRIF Las Acacias; General Ricardos 179 - 28025 Madrid; Tel. + 34915250893ES

    Sitúate : revista digital de situaciones de aprendizaje

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    La situación de aprendizaje consiste en el diseño y realización de una serie de actividades relacionadas con la preservación de los Osos Polares del Ártico en Canadá y de toma de conciencia sobre los efectos del Cambio Climático producido por la acción del hombre. Por último qué actuaciones desde la Escuela y la Familia se pueden hacer para mitigar el mismo. Se consigue con ello, contextualizar el desarrollo del currículo en la realidad educativa. Con la propuesta que aquí se hace se estan abordando la competencia del conocimiento e interacción con el mundo físico, tratamiento de la información y competencia digital y la competencia social y ciudadana. La adquisición de estos aprendizajes conectan con las metas, principios, objetivos y acciones que rigen el Proyecto Educativo de Centro en la medida que produce un desarrollo integral de los niños/as en el primer y segundo ciclo de Primaria.ES

    Light conditions and heterogeneity in illumination affect growth and survival of Octopus vulgaris paralarvae reared in the hatchery

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    7 pages, 3 tables, 4 figuresIn order to succeed in common octopus (Octopus vulgaris) aquaculture, it is necessary to overcome the massive paralarval mortalities, which are likely related to zootechnical and/or nutritional aspects. Among the zootechnical aspects, the effect of light could be vital for the development of paralarvae given their sophisticated visual system. O. vulgaris paralarvae display vertical behavior in the wild, being in deeper waters during the day and close to the surface at night. For this reason, the present study traces a collection of light assays in captivity, to test ecologically-driven hypotheses on the growth and survival of octopus paralarvae. The first assay tested a factorial combination of light colors (blue vs white) and intensity (low ~13 lx (36 W/m2), medium ~87 lx (151 W/m2) and high ~265 lx (422 W/m2)). The results pointed to a significant negative impact of low light intensities (13 and 87 lx) on paralarval growth. The second assay was designed to contrast light colors (blue vs white), different levels of intensities (300 lx (478 W/m2) vs 600 lx (1077 W/m2)) and partial coverage of the tanks using a shade mesh, named as “shadow zone” (half-covered vs non-covered tanks). In half-covered tanks, survival was significantly improved, with the best results coming from half-covered tanks with blue light and 600 lx, but no differences in dry weight were observed. The third experiment tested a factor called “light source position” with two levels: “Control” when the light incidence angle was 0° with respect to the normal direction (i.e. perpendicular to the water surface), and “Oblique” when the light incidence angle was 60° with respect to the normal direction. In this experiment, survival significantly improved under oblique light but no differences in dry weight were detected. The last experiment was an unifactorial design combining “light source position” and “tank partial coverage” with three treatments: i) control light with uncovered tanks, ii) oblique light with uncovered tanks, iii) control light with semi-covered tanks. Oblique light with uncovered tanks was associated with a higher survival rate but without statistical significance, probably due to data variability. It can be concluded that light intensity tended to affect paralarval dry weight, whereas the existence of a shadow zone or oblique light are more related with an improvement of survival ratesThis study has been supported by the project OCTOWELF (AGL 2013-49101-C2-1-R) funded by the Spanish Government and the COST Action “CephsInAction” (FA1301) funded by the COST programme (EU)Peer reviewe

    Efficient expression of bioactive murine IL12 as a self-processing P2A polypeptide driven by inflammation-regulated promoters in tumor cell lines

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    Interleukin 12 (IL12) is a heterodimeric proinflammatory cytokine that has shown promise as an anticancer agent. However, despite encouraging results in animal models, clinical trials involving IL12 have been unsuccessful due to toxic side effects associated with its systemic administration, prompting investigation into new delivery methods to confine IL12 expression to the tumor environment. In this study we used the self-cleaving property of the 2A peptide to express both codon-optimized murine IL12 subunits (muIL12opt) as a self-processing polypeptide (muIL12opt-P2A). We cloned muIL12opt-P2A driven by different inflammation-induced lentiviral expression systems to transduce murine tumor cell lines commonly employed in syngeneic tumor models. We confirmed the inducibility of these systems in vitro and in vivo and demonstrated the successful expression of both IL12 subunits and the release of bioactive IL12 upon proinflammatory stimulation in vitro. Therefore, IL12 release driven by these inflammation-regulated expression systems might be useful not only to address the impact of IL12 expression in the tumor environment but also to achieve a local IL12 release controlled by the inflammation state of the tumor, thus avoiding toxic side effects associated with systemic administration.A.R. is supported by the Spanish Ministry of Economy and Competitivity (MINECO; SAF2012-32166) and the Comunidad Autónoma de Madrid (S2010/BMD-2312). JMZ is supported by the Instituto de Salud de Carlos III (PI12/01135).Peer Reviewe
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