3,144 research outputs found

    Methane reduction in Kazakhstan: Present situation and potential

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    The battle against methane emissions has evolved into a global mission, with 150 producing countries worldwide, including the United States, Canada, Germany, Australia, and others, pledging their commitment to the Global Methane Pledge. This new initiative was introduced in 2021 during COP26 in Glasgow, United Kingdom, as part of the ongoing efforts to implement the Paris Agreement. The primary objective of this Agreement is a collective endeavour to reduce methane emissions by 30% by the year 2030. In this article, the authors analyse current methane emissions and provide recommendations to the country’s government regarding its participation in the Global Methane Pledge by utilising official national statistical data and insights from the EIA and employing predictive modelling techniques

    TOI-5126: A hot super-Neptune and warm Neptune pair discovered by TESS\textit{TESS} and CHEOPS\textit{CHEOPS}

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    We present the confirmation of a hot super-Neptune with an exterior Neptune companion orbiting a bright (V = 10.1 mag) F-dwarf identified by the Transiting Exoplanet Survey Satellite\textit{Transiting Exoplanet Survey Satellite} (TESS\textit{TESS}). The two planets, observed in sectors 45, 46 and 48 of the TESS\textit{TESS} extended mission, are 4.74−0.14+0.164.74^{+0.16}_{-0.14} R⊕R_{\oplus} and 3.86−0.16+0.173.86^{+0.17}_{-0.16} R⊕R_{\oplus} with 5.4588385−0.0000072+0.00000705.4588385^{+0.0000070}_{-0.0000072} d and 17.8999−0.0013+0.001817.8999^{+0.0018}_{-0.0013} d orbital periods, respectively. We also obtained precise space based photometric follow-up of the system with ESAs CHaracterising ExOplanets Satellite\textit{CHaracterising ExOplanets Satellite} (CHEOPS\textit{CHEOPS}) to constrain the radius and ephemeris of TOI-5126 b. TOI 5126 b is located in the "hot Neptune Desert" and is an ideal candidate for follow-up transmission spectroscopy due to its high predicted equilibrium temperature (Teq=1442−40+46T_{eq} = 1442^{+46}_{-40} K) implying a cloud-free atmosphere. TOI-5126 c is a warm Neptune (Teq=971−27+31T_{eq}= 971^{+31}_{-27} K) also suitable for follow-up. Tentative transit timing variations (TTVs) have also been identified in analysis, suggesting the presence of at least one additional planet, however this signal may be caused by spot-crossing events, necessitating further precise photometric follow-up to confirm these signals.Comment: Accepted in MNRAS, 18 pages, 14 figure

    Compressed representation of a partially defined integer function over multiple arguments

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    In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one

    Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

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    Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters

    TOI-1695 b:A Water World Orbiting an Early-M Dwarf in the Planet Radius Valley

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    Characterizing the bulk compositions of transiting exoplanets within the M dwarf radius valley offers a unique means to establish whether the radius valley emerges from an atmospheric mass-loss process or is imprinted by planet formation itself. We present the confirmation of such a planet orbiting an early-M dwarf (Tmag = 11.0294 ± 0.0074, Ms = 0.513 ± 0.012 M⊙, Rs = 0.515 ± 0.015 R⊙, and Teff = 3690 ± 50 K): TOI-1695 b (P = 3.13 days and Rp = 1.90−0.14+0.16 R⊕ ). TOI-1695 b’s radius and orbital period situate the planet between model predictions from thermally driven mass loss versus gas depleted formation, offering an important test case for radius valley emergence models around early-M dwarfs. We confirm the planetary nature of TOI-1695 b based on five sectors of TESS data and a suite of follow-up observations including 49 precise radial velocity measurements taken with the HARPS-N spectrograph. We measure a planetary mass of 6.36 ± 1.00 M⊕, which reveals that TOI-1695 b is inconsistent with a purely terrestrial composition of iron and magnesium silicate, and instead is likely a water-rich planet. Our finding that TOI-1695 b is not terrestrial is inconsistent with the planetary system being sculpted by thermally driven mass loss. We present a statistical analysis of seven well-characterized planets within the M dwarf radius valley demonstrating that a thermally driven mass-loss scenario is unlikely to explain this population.</p

    TESS Hunt for Young and Maturing Exoplanets (THYME) VII : Membership, rotation, and lithium in the young cluster Group-X and a new young exoplanet

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    The public, all-sky surveys Gaia and TESS provide the ability to identify new young associations and determine their ages. These associations enable study of planetary evolution by providing new opportunities to discover young exoplanets. A young association was recently identified by Tang et al. and F{\"u}rnkranz et al. using astrometry from Gaia (called "Group-X" by the former). In this work, we investigate the age and membership of this association; and we validate the exoplanet TOI 2048 b, which was identified to transit a young, late G dwarf in Group-X using photometry from TESS. We first identified new candidate members of Group-X using Gaia EDR3 data. To infer the age of the association, we measured rotation periods for candidate members using TESS data. The clear color--period sequence indicates that the association is the same age as the 300±50300\pm50 Myr-old NGC 3532. We obtained optical spectra for candidate members that show lithium absorption consistent with this young age. Further, we serendipitously identify a new, small association nearby Group-X, which we call MELANGE-2. Lastly, we statistically validate TOI 2048 b, which is 2.6±0.22.6\pm0.2 \rearth\ radius planet on a 13.8-day orbit around its 300 Myr-old host star.Comment: Revised to correct error in reported planet radius (original: 2.1 Earth radii, corrected: 2.6 Earth radii) and units for planetary radius ratio entries in Table 8. All data tables available open-access with the AJ articl

    The TESS Grand Unified Hot Jupiter Survey. I. Ten TESS Planets

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    We report the discovery of ten short-period giant planets (TOI-2193A b, TOI-2207 b, TOI-2236 b, TOI-2421 b, TOI-2567 b, TOI-2570 b, TOI-3331 b, TOI-3540A b, TOI-3693 b, TOI-4137 b). All of the planets were identified as planet candidates based on periodic flux dips observed by NASA's Transiting Exoplanet Survey Satellite (TESS). The signals were confirmed to be from transiting planets using ground-based time-series photometry, high angular resolution imaging, and high-resolution spectroscopy coordinated with the TESS Follow-up Observing Program. The ten newly discovered planets orbit relatively bright F and G stars (G<12.5G < 12.5,~TeffT_\mathrm{eff} between 4800 and 6200 K). The planets' orbital periods range from 2 to 10~days, and their masses range from 0.2 to 2.2 Jupiter masses. TOI-2421 b is notable for being a Saturn-mass planet and TOI-2567 b for being a ``sub-Saturn'', with masses of 0.322±0.0730.322\pm 0.073 and 0.195±0.0300.195\pm 0.030 Jupiter masses, respectively. In most cases, we have little information about the orbital eccentricities. Two exceptions are TOI-2207 b, which has an 8-day period and a detectably eccentric orbit (e=0.17±0.05e = 0.17\pm0.05), and TOI-3693 b, a 9-day planet for which we can set an upper limit of e<0.052e < 0.052. The ten planets described here are the first new planets resulting from an effort to use TESS data to unify and expand on the work of previous ground-based transit surveys in order to create a large and statistically useful sample of hot Jupiters.Comment: 44 pages, 15 tables, 21 figures; revised version submitted to A

    TOI-4010: A System of Three Large Short-Period Planets With a Massive Long-Period Companion

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    We report the confirmation of three exoplanets transiting TOI-4010 (TIC-352682207), a metal-rich K dwarf observed by TESS in Sectors 24, 25, 52, and 58. We confirm these planets with HARPS-N radial velocity observations and measure their masses with 8 - 12% precision. TOI-4010 b is a sub-Neptune (P=1.3P = 1.3 days, Rp=3.02−0.08+0.08 R⊕R_{p} = 3.02_{-0.08}^{+0.08}~R_{\oplus}, Mp=11.00−1.27+1.29 M⊕M_{p} = 11.00_{-1.27}^{+1.29}~M_{\oplus}) in the hot Neptune desert, and is one of the few such planets with known companions. Meanwhile, TOI-4010 c (P=5.4P = 5.4 days, Rp=5.93−0.12+0.11 R⊕R_{p} = 5.93_{-0.12}^{+0.11}~R_{\oplus}, Mp=20.31−2.11+2.13 M⊕M_{p} = 20.31_{-2.11}^{+2.13}~M_{\oplus}) and TOI-4010 d (P=14.7P = 14.7 days, Rp=6.18−0.14+0.15 R⊕R_{p} = 6.18_{-0.14}^{+0.15}~R_{\oplus}, Mp=38.15−3.22+3.27 M⊕M_{p} = 38.15_{-3.22}^{+3.27}~M_{\oplus}) are similarly-sized sub-Saturns on short-period orbits. Radial velocity observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a long-period, eccentric orbit (P∌762P \sim 762 days and e∌0.26e \sim 0.26 based on available observations). TOI-4010 is one of the few systems with multiple short-period sub-Saturns to be discovered so far.Comment: 26 pages, 16 figures, published in A
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