110 research outputs found

    Photometry of 25 Large Main-belt Asteroids with TRAPPIST-North and -South

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    editorial reviewedDensely sampled lightcurves of 25 large main-belt asteroids were obtained with the TRAPPIST-South (TS) and TRAPPIST-North (TN) telescopes from 2017 to 2021. Those observations took place in support of an ESO large program aiming at observing a representative sample of large asteroids with the ESO VLT for precise shape determination from adaptive optics high-resolution imaging. Synodic rotation periods and lightcurve amplitudes have been determined for all but one target. Six asteroids were observed during two different apparitions. The data have been submitted to the ALCDEF database

    Lightcurve Based Determination of 10 Hygiea'S Rotational Period With Trappist-North and -South

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    peer reviewedA densely-sampled lightcurve of the large main-belt asteroid 10 Hygiea was obtained with the TRAPPISTSouth (TS) and TRAPPIST-North (TN) telescopes in 2018 September and October. We found its synodic rotation period and amplitude to be 13.8224 ± 0.0005 h and 0.27 mag. The data have been submitted to the ALCDEF database

    The use of plants in the traditional treatment of diabetes patients: survey in southern Morocco

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    This study was conducted in public healthcare establishments in Guelmim city in south of Morocco to report medicinal plants used in folk medicine to treat diabetes. Three hundred sixty-two informants were interviewed through semi structured interviews. The inventory includes scientific, popular and common names of the plants, used parts and method of preparation. The survey shows that 24.6% of the patients use these plants. Twenty-seven medicinal plants belonging to seventeen families were inventoried and three species were cited for the first time in the treatment of diabetes in Morocco. Olea europea L., Artemisia herba-alba Asso and Trigonella foenum-graecum L. are the most plant species used to treat diabetes, and the two most cited families are Lamiaceae (5 species) and Apiaceae (4 species). Leaves represented the most utilized part of plants and decoction was the most cited mode of preparation of drugs. The present study highlights the wide variety of herbal remedies used to treat diabetes and the frequency of this use in diabetic patients

    SPECULOOS Northern Observatory: Searching for Red Worlds in the Northern Skies

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    peer reviewedSPECULOOS is a ground-based transit survey consisting of six identical 1 m robotic telescopes. The immediate goal of the project is to detect temperate terrestrial planets transiting nearby ultracool dwarfs (late M-dwarf stars and brown dwarfs), which could be amenable for atmospheric research with the next generation of telescopes. Here, we report the developments of the northern counterpart of the project-SPECULOOS Northern Observatory, and present its performance during the first three years of operations from mid-2019 to mid-2022. Currently, the observatory consists of one telescope, which is named Artemis. The Artemis telescope demonstrates remarkable photometric precision, allowing it to be ready to detect new transiting terrestrial exoplanets around ultracool dwarfs. Over the period of the first three years after the installation, we observed 96 objects from the SPECULOOS target list for 6000 hr with a typical photometric precision of 0.5%, and reaching a precision of 0.2% for relatively bright non-variable targets with a typical exposure time of 25 s. Our weather downtime (clouds, high wind speed, high humidity, precipitation and/or high concentration of dust particles in the air) over the period of three years was 30% of overall night time. Our actual downtime is 40% because of additional time loss associated with technical problems

    Three Warm Jupiters around Solar-analog Stars Detected with TESS*

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    We report the discovery and characterization of three giant exoplanets orbiting solar-analog stars, detected by the TESS space mission and confirmed through ground-based photometry and radial velocity measurements taken at La Silla observatory with FEROS. TOI-2373 b is a warm Jupiter orbiting its host star every ∼13.3 days, and is one of the most massive known exoplanet with a precisely determined mass and radius around a star similar to the Sun, with an estimated mass of m _p = 9.30.2+0.2Mjup{9.3}_{-0.2}^{+0.2}\,{M}_{\mathrm{jup}} and a radius of r _p = 0.930.2+0.2Rjup{0.93}_{-0.2}^{+0.2}\,{R}_{\mathrm{jup}} . With a mean density of ρ=14.41.0+0.9gcm3\rho ={14.4}_{-1.0}^{+0.9}\,{\rm{g}}\,{\mathrm{cm}}^{-3} , TOI-2373 b is among the densest planets discovered so far. TOI-2416 b orbits its host star on a moderately eccentric orbit with a period of ∼8.3 days and an eccentricity of e = 0.320.02+0.02{0.32}_{-0.02}^{+0.02} . TOI-2416 b is more massive than Jupiter with m _p = 3.00.09+0.10Mjup{3.0}_{-0.09}^{+0.10}\,{M}_{\mathrm{jup}} , however is significantly smaller with a radius of r _p = 0.880.02+0.02,Rjup{0.88}_{-0.02}^{+0.02},{R}_{\mathrm{jup}} , leading to a high mean density of ρ=5.40.3+0.3gcm3\rho ={5.4}_{-0.3}^{+0.3}\,{\rm{g}}\,{\mathrm{cm}}^{-3} . TOI-2524 b is a warm Jupiter near the hot Jupiter transition region, orbiting its star every ∼7.2 days on a circular orbit. It is less massive than Jupiter with a mass of m _p = 0.640.04+0.04Mjup{0.64}_{-0.04}^{+0.04}\,{M}_{\mathrm{jup}} , and is consistent with an inflated radius of r _p = 1.000.03+0.02Rjup{1.00}_{-0.03}^{+0.02}\,{R}_{\mathrm{jup}} , leading to a low mean density of ρ=0.790.08+0.08gcm3\rho ={0.79}_{-0.08}^{+0.08}\,{\rm{g}}\,{\mathrm{cm}}^{-3} . The newly discovered exoplanets TOI-2373 b, TOI-2416 b, and TOI-2524 b have estimated equilibrium temperatures of 86010+10{860}_{-10}^{+10} K, 108010+10{1080}_{-10}^{+10} K, and 110020+20{1100}_{-20}^{+20} K, respectively, placing them in the sparsely populated transition zone between hot and warm Jupiters

    TOI-3235 b: a transiting giant planet around an M4 dwarf star

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    We present the discovery of TOI-3235 b, a short-period Jupiter orbiting an M-dwarf with a stellar mass close to the critical mass at which stars transition from partially to fully convective. TOI-3235 b was first identified as a candidate from TESS photometry, and confirmed with radial velocities from ESPRESSO, and ground-based photometry from HATSouth, MEarth-South, TRAPPIST-South, LCOGT, and ExTrA. We find that the planet has a mass of 0.665±0.025MJ\mathrm{0.665\pm0.025\,M_J} and a radius of 1.017±0.044RJ\mathrm{1.017\pm0.044\,R_J}. It orbits close to its host star, with an orbital period of 2.5926d\mathrm{2.5926\,d}, but has an equilibrium temperature of 604K\mathrm{\approx 604 \, K}, well below the expected threshold for radius inflation of hot Jupiters. The host star has a mass of 0.3939±0.0030M\mathrm{0.3939\pm0.0030\,M_\odot}, a radius of 0.3697±0.0018R\mathrm{0.3697\pm0.0018\,R_\odot}, an effective temperature of 3389K\mathrm{3389 \, K}, and a J-band magnitude of 11.706±0.025\mathrm{11.706\pm0.025}. Current planet formation models do not predict the existence of gas giants such as TOI-3235 b around such low-mass stars. With a high transmission spectroscopy metric, TOI-3235 b is one of the best-suited giants orbiting M-dwarfs for atmospheric characterization.Comment: 15 pages, 4 figures. Accepted for publication in APJ

    Vetting of 384 TESS Objects of Interest with TRICERATOPS and Statistical Validation of 12 Planet Candidates

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    We present TRICERATOPS, a new Bayesian tool that can be used to vet and validate TESS Objects of Interest (TOIs). We test the tool on 68 TOIs that have been previously confirmed as planets or rejected as astrophysical false positives. By looking in the false positive probability (FPP) -- nearby false positive probability (NFPP) plane, we define criteria that TOIs must meet to be classified as validated planets (FPP < 0.015 and NFPP < 10^-3), likely planets (FPP 10^-1). We apply this procedure on 384 unclassified TOIs and statistically validate 12, classify 125 as likely planets, and classify 52 as likely nearby false positives. Of the 12 statistically validated planets, 9 are newly validated. TRICERATOPS is currently the only TESS vetting and validation tool that models transits from nearby contaminant stars in addition to the target star. We therefore encourage use of this tool to prioritize follow-up observations that confirm bona fide planets and identify false positives originating from nearby stars.Comment: Accepted to A

    VaTEST III : validation of 8 potential super-earths from TESS data

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    Funding: The ULiege’s contribution to SPECULOOS has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) (grant Agreement n◦ 336480/SPECULOOS). This research is in part funded by the European Union’s Horizon 2020 research and innovation programme (grants agreements n◦ 803193/BEBOP), and from the Science and Technology Facilities Council (STFC; grant n◦ ST/S00193X/1, and ST/W000385/1).NASA’s all-sky survey mission, the Transiting Exoplanet Survey Satellite (TESS), is specifically engineered to detect exoplanets that transit bright stars. Thus far, TESS has successfully identified approximately 400 transiting exoplanets, in addition to roughly 6 000 candidate exoplanets pending confirmation. In this study, we present the results of our ongoing project, the Validation of Transiting Exoplanets using Statistical Tools (VaTEST). Our dedicated effort is focused on the confirmation and characterisation of new exoplanets through the application of statistical validation tools. Through a combination of ground-based telescope data, high-resolution imaging, and the utilisation of the statistical validation tool known as TRICERATOPS, we have successfully discovered eight potential super-Earths. These planets bear the designations: TOI-238b (1.61 +0.09−0.10 R ⊕ ), TOI-771b (1.42 +0.11−0.09 R ⊕ ), TOI-871b (1.66 +0.11−0.11 R ⊕ ), TOI-1467b (1.83 +0.16−0.15 R ⊕ ), TOI-1739b (1.69 +0.10−0.08 R ⊕ ), TOI-2068b (1.82 +0.16−0.15 R ⊕ ), TOI-4559b (1.42 +0.13−0.11 R ⊕ ), and TOI-5799b (1.62 +0.19−0.13 R ⊕ ). Among all these planets, six of them fall within the region known as ‘keystone planets’, which makes them particularly interesting for study. Based on the location of TOI-771b and TOI-4559b below the radius valley we characterised them as likely super-Earths, though radial velocity mass measurements for these planets will provide more details about their characterisation. It is noteworthy that planets within the size range investigated herein are absent from our own solar system, making their study crucial for gaining insights into the evolutionary stages between Earth and Neptune.Peer reviewe
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