88 research outputs found

    Correlation between the cardiorespiratory endurance, dynamic postural control and thoracic kyphosis angle among the students

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    Background: Any deviation in the normal spinal alignment can alter the cardiorespiratory endurance and the posture control. The aim of present study was to investigate the correlation between cardiorespiratory endurance, dynamic postural control and kyphosis angle among the students. Materials and Methods: This cross-sectional study was carried out on students (n=100; 48 girls and 52 boys) selected randomly according to inclusion criteria. Cardiorespiratory endurance, postural control and kyphosis angle were assessed using shuttle run test, Y balance test and flexible ruler, respectively. Normal distribution of the data was assessed using the Kolmogorov–Smirnov test. Data were analyzed using Pearson correlation product moment and linear regression (P≤0.05). Results: The results showed a significant negative correlation between the cardiorespiratory endurance and kyphosis angle (P=0.012, r=-0.3.3). In addition, a significant negative correlation was observed between the dynamic postural control and kyphosis angle (P=0.003, r=-0.254). Conclusion: According to our findings it seems mandatory for health and school's, sport coaches to screen the student's spinal deformities and evaluate its associated complications (e.g. decreased cardiorespiratory endurance and postural balance)

    Regaining the FORS: optical ground-based transmission spectroscopy of the exoplanet WASP-19b with VLT+FORS2

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    In the past few years, the study of exoplanets has evolved from being pure discovery, then being more exploratory in nature and finally becoming very quantitative. In particular, transmission spectroscopy now allows the study of exoplanetary atmospheres. Such studies rely heavily on space-based or large ground-based facilities, because one needs to perform time-resolved, high signal-to-noise spectroscopy. The very recent exchange of the prisms of the FORS2 atmospheric diffraction corrector on ESO's Very Large Telescope should allow us to reach higher data quality than was ever possible before. With FORS2, we have obtained the first optical ground-based transmission spectrum of WASP-19b, with 20 nm resolution in the 550--830 nm range. For this planet, the data set represents the highest resolution transmission spectrum obtained to date. We detect large deviations from planetary atmospheric models in the transmission spectrum redwards of 790 nm, indicating either additional sources of opacity not included in the current atmospheric models for WASP-19b or additional, unexplored sources of systematics. Nonetheless, this work shows the new potential of FORS2 for studying the atmospheres of exoplanets in greater detail than has been possible so far.Comment: 7 pages, 9 figures, 3 tables. Accepted for publication in A&

    A precise blue-optical transmission spectrum from the ground: evidence for haze in the atmosphere of WASP-74b

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    We report transmission spectroscopy of the bloated hot Jupiter WASP-74b in the wavelength range from 4000 to 6200 Å. We observe two transit events with the Very Large Telescope (VLT) Focal Reducer and Spectrograph and present a new method to measure the exoplanet transit depth as a function of wavelength. The new method removes the need for a reference star in correcting the spectroscopic light curves for the impact of atmospheric extinction. It also provides improved precision, compared to other techniques, reaching an average transit depth uncertainty of 211 ppm for a solar-type star of V = 9.8 mag and over wavelength bins of 80 Å. The VLT transmission spectrum is analysed both individually and in combination with published data from Hubble Space Telescope and Spitzer. The spectrum is found to exhibit a mostly featureless slope and equilibrium chemistry retrievals with PLATON favour hazes in the upper atmosphere of the exoplanet. Free chemistry retrievals with AURA further support the presence of hazes. While additional constraints are possible depending on the choice of atmospheric model, they are not robust and may be influenced by residual systematics in the data sets. Our results demonstrate the utility of new techniques in the analysis of optical, ground-based spectroscopic data and can be highly complementary to follow-up observations in the infrared with JWST

    Detection of titanium oxide in the atmosphere of a hot Jupiter.

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    As an exoplanet transits its host star, some of the light from the star is absorbed by the atoms and molecules in the planet's atmosphere, causing the planet to seem bigger; plotting the planet's observed size as a function of the wavelength of the light produces a transmission spectrum. Measuring the tiny variations in the transmission spectrum, together with atmospheric modelling, then gives clues to the properties of the exoplanet's atmosphere. Chemical species composed of light elements-such as hydrogen, oxygen, carbon, sodium and potassium-have in this way been detected in the atmospheres of several hot giant exoplanets, but molecules composed of heavier elements have thus far proved elusive. Nonetheless, it has been predicted that metal oxides such as titanium oxide (TiO) and vanadium oxide occur in the observable regions of the very hottest exoplanetary atmospheres, causing thermal inversions on the dayside. Here we report the detection of TiO in the atmosphere of the hot-Jupiter planet WASP-19b. Our combined spectrum, with its wide spectral coverage, reveals the presence of TiO (to a confidence level of 7.7σ), a strongly scattering haze (7.4σ) and sodium (3.4σ), and confirms the presence of water (7.9σ) in the atmosphere

    TOI-4860 b, a short-period giant planet transiting an M3.5 dwarf

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    We report the discovery and characterisation of a giant transiting planet orbiting a nearby M3.5V dwarf (d = 80.4 pc, GG = 15.1 mag, KK=11.2 mag, R_\star = 0.358 ±\pm 0.015 R_\odot, M_\star = 0.340 ±\pm 0.009 M_\odot). Using the photometric time series from TESS sectors 10, 36, 46, and 63 and near-infrared spectrophotometry from ExTrA, we measured a planetary radius of 0.77 ±\pm 0.03 RJ_J and an orbital period of 1.52 days. With high-resolution spectroscopy taken by the CFHT/SPIRou and ESO/ESPRESSO spectrographs, we refined the host star parameters ([Fe/H] = 0.27 ±\pm 0.12) and measured the mass of the planet (0.273 ±\pm 0.006 MJ_J). Based on these measurements, TOI-4860 b joins the small set of massive planets (>>80 ME_E) found around mid to late M dwarfs (<<0.4 R_\odot), providing both an interesting challenge to planet formation theory and a favourable target for further atmospheric studies with transmission spectroscopy. We identified an additional signal in the radial velocity data that we attribute to an eccentric planet candidate (e=0.66±0.09e=0.66\pm0.09) with an orbital period of 427±7427\pm7~days and a minimum mass of 1.66±0.261.66\pm 0.26 MJ_J, but additional data would be needed to confirm this.Comment: 16 pages, 14 figures, accepted for publication in A&

    Atmospheric retrieval of exoplanets

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    Exoplanetary atmospheric retrieval refers to the inference of atmospheric properties of an exoplanet given an observed spectrum. The atmospheric properties include the chemical compositions, temperature profiles, clouds/hazes, and energy circulation. These properties, in turn, can provide key insights into the atmospheric physicochemical processes of exoplanets as well as their formation mechanisms. Major advancements in atmospheric retrieval have been made in the last decade, thanks to a combination of state-of-the-art spectroscopic observations and advanced atmospheric modeling and statistical inference methods. These developments have already resulted in key constraints on the atmospheric H2O abundances, temperature profiles, and other properties for several exoplanets. Upcoming facilities such as the JWST will further advance this area. The present chapter is a pedagogical review of this exciting frontier of exoplanetary science. The principles of atmospheric retrievals of exoplanets are discussed in detail, including parametric models and statistical inference methods, along with a review of key results in the field. Some of the main challenges in retrievals with current observations are discussed along with new directions and the future landscape
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