Na I and Hα\alpha absorption features in the atmosphere of MASCARA-2b/KELT-20b

We have used the HARPS-North high resolution spectrograph ($\mathcal{R}$=115 000) at TNG to observe one transit of the highly irradiated planet MASCARA-2b/KELT-20b. Using only one transit observation, we are able to clearly resolve the spectral features of the atomic sodium (Na I) doublet and the H$\alpha$ line in its atmosphere, measuring absorption depths of 0.17$\pm$0.03$\%$ and 0.59$\pm$0.08$\%$ for a 0.75 $\AA$ passband, respectively. These absorptions are corroborated with the transmission measured from their respective transmission light curves, which show a large Rossiter-McLaughlin effect. In case of H$\alpha$, this absorption corresponds to an effective radius of $R_{\lambda}/R_P$=1.20$\pm$0.04. While the S/N of the final transmission spectrum is not sufficient to adjust different temperature profiles to the lines, we find that higher temperatures than the equilibrium are needed to explain the lines contrast. Particularly, we find that the Na I lines core require a temperature of T=4210$\pm$180K and that H$\alpha$ requires T=4330$\pm$520K. MASCARA-2b, like other planets orbiting A-type stars, receives a large amount of UV energy from its host star. This energy excites the atomic hydrogen and produces H$\alpha$ absorption, leading to the expansion and abrasion of the atmosphere. The study of other Balmer lines in the transmission spectrum would allow the determination of the atmospheric temperature profile and the calculation of the lifetime of the atmosphere. In the case of MASCARA-2b, residual features are observed in the H$\beta$ and H$\gamma$ lines, but they are not statistically significant. More transit observations are needed to confirm our findings in Na I and H$\alpha$, and to build up enough S/N to explore the presence of H$\beta$ and H$\gamma$ planetary absorptions.Comment: 14 pages, 12 figure

MASCARA-2 b: A hot Jupiter transiting the mV=7.6m_V=7.6 A-star HD185603

In this paper we present MASCARA-2 b, a hot Jupiter transiting the $m_V=7.6$ A2 star HD 185603. Since early 2015, MASCARA has taken more than 1.6 million flux measurements of the star, corresponding to a total of almost 3000 hours of observations, revealing a periodic dimming in the flux with a depth of $1.3\%$. Photometric follow-up observations were performed with the NITES and IAC80 telescopes and spectroscopic measurements were obtained with the Hertzsprung SONG telescope. We find MASCARA-2 b orbits HD 185603 with a period of $3.474119^{+0.000005}_{-0.000006}~\rm{days}$ at a distance of $0.057 \pm 0.006~\rm{AU}$, has a radius of $1.83 \pm 0.07~\rm{R}_{\rm{J}}$ and place a $99\%$ upper limit on the mass of $< 17~\rm{M}_{\rm{J}}$. HD 185603 is a rapidly rotating early-type star with an effective temperature of $8980^{+90}_{-130}~\rm{K}$ and a mass and radius of $1.89^{+0.06}_{-0.05}~M_\odot$, $1.60 \pm 0.06~R_\odot$, respectively. Contrary to most other hot Jupiters transiting early-type stars, the projected planet orbital axis and stellar spin axis are found to be aligned with $\lambda=0.6 \pm 4^\circ$. The brightness of the host star and the high equilibrium temperature, $2260 \pm 50~\rm{K}$, of MASCARA-2 b make it a suitable target for atmospheric studies from the ground and space. Of particular interest is the detection of TiO, which has recently been detected in the similarly hot planets WASP-33 b and WASP-19 b.Comment: 8 pages, 4 figures, Accepted for publication in A&

Furrow and Ridge Soil Nitrogen Mineralization in a Surface Irrigated Artichoke Field

[EN] Quantitative knowledge of soil organic nitrogen net mineralization (NNM) in field conditions is crucial to optimize N fertilization of crops. In a field fertilization trial of artichokes 48 PE tubes were inserted to 20 cm depth in the soil in plant row and irrigation furrows and soil samples were periodically taken during two and a half months to determine NNM. A parallel essay with disturbed samples from the same procedence was carried out in the laboratory at 25ºC and 10 kPa soil water tension. Soil sample position (ridge and furrow) did not significantly determined NNM in the laboratory essay. Although NNM (obtained from laboratory incubation and corrected to field soil temperature and moisture monitored during the experimental period) overpredicted measured field NNM, matching of both was better than those reported in other studies. NNM rate for the 76 days period of incubation predicted from lab data was 22.9 kg N/ ha x 0.1 m while corresponding field values corrected by Br- or Cl- mass balance were 10% and 20% lower respectively in ridge position and under 40% lower by either method in furrow position.The research reported in this paper was supported by a fund from CICYT-INIA (project RTA01-117-C2-2)Lidón, A.; Bautista, I.; De La Iglesia, F.; Oliver Talens, J.; Llorca, R.; Cruz-Romero, G. (2006). Furrow and Ridge Soil Nitrogen Mineralization in a Surface Irrigated Artichoke Field. Acta Horticulturae. (700):71-74. https://doi.org/10.17660/ActaHortic.2006.700.7S717470

Data calibration for the MASCARA and bRing instruments

Aims: MASCARA and bRing are photometric surveys designed to detect variability caused by exoplanets in stars with $m_V < 8.4$. Such variability signals are typically small and require an accurate calibration algorithm, tailored to the survey, in order to be detected. This paper presents the methods developed to calibrate the raw photometry of the MASCARA and bRing stations and characterizes the performance of the methods and instruments. Methods: For the primary calibration a modified version of the coarse decorrelation algorithm is used, which corrects for the extinction due to the earth's atmosphere, the camera transmission, and intrapixel variations. Residual trends are removed from the light curves of individual stars using empirical secondary calibration methods. In order to optimize these methods, as well as characterize the performance of the instruments, transit signals were injected in the data. Results: After optimal calibration an RMS scatter of 10 mmag at $m_V \sim 7.5$ is achieved in the light curves. By injecting transit signals with periods between one and five days in the MASCARA data obtained by the La Palma station over the course of one year, we demonstrate that MASCARA La Palma is able to recover 84.0, 60.5 and 20.7% of signals with depths of 2, 1 and 0.5% respectively, with a strong dependency on the observed declination, recovering 65.4% of all transit signals at $\delta > 0^\circ$ versus 35.8% at $\delta < 0^\circ$. Using the full three years of data obtained by MASCARA La Palma to date, similar recovery rates are extended to periods up to ten days. We derive a preliminary occurrence rate for hot Jupiters around A-stars of ${>} 0.4 \%$, knowing that many hot Jupiters are still overlooked. In the era of TESS, MASCARA and bRing will provide an interesting synergy for finding long-period (${>} 13.5$ days) transiting gas-giant planets around the brightest stars.Comment: 18 pages, 17 figures, accepted for publication in A&

Nieuwsgierigheid in kaart gebracht:Validatiestudie van de Epistemic Curiosity Scale in de Nederlandse onderwijscontext

De doelstelling van het onderzoek is de validering van een vertaald meetinstrument om nieuwsgierigheid van leerlingen en studenten in Nederland in kaart te kunnen brengen. De centrale onderzoeksvraag luidt: In hoeverre geeft de vertaalde, Nederlandstalige versie van de Epistemic Curiosity Scale (Litman, 2008) een betrouwbaar en valide beeld van de mate van nieuwsgierigheid van leerlingen in het voortgezet onderwijs en studenten in het mbo en hbo? De vragenlijst onderscheidt twee componenten van nieuwsgierigheid: gevoelens van deprivatie (D-type nieuwsgierigheid) en gevoelens van interesse (I-type nieuwsgierigheid). De vragenlijst is afgenomen bij 131 leerlingen in het voortgezet onderwijs, 188 mbo-studenten en 282 hbo-studenten. Uit de resultaten komt eenduidig naar voren dat het vertaalde meetinstrument de mate van nieuwsgierigheid van leerlingen en studenten goed in kaart kan brengen. De I-type en D-type schalen zijn betrouwbaar en geven een redelijk valide beeld van de mate van nieuwsgierigheid van leerlingen in het voortgezet onderwijs en studenten in het mbo en hbo. Wel bleek dat de model fit nog verder geoptimaliseerd kan worden door de formulering van enkele items te verbeteren