Suchergebnisse

We report the discovery of a warm Neptune and a hot sub-Neptune transiting TOI-421 (BD-14 1137, TIC 94986319), a bright (V = 9.9) G9 dwarf star in a visual binary system observed by the Transiting Exoplanet Survey Satellite (TESS) space mission in Sectors 5 and 6. We performed ground-based follow-up observations-comprised of Las Cumbres Observatory Global Telescope transit photometry, NIRC2 adaptive optics imaging, and FIbre-fed Echelle Spectrograph, CORALIE, High Accuracy Radial velocity Planet Searcher, High Resolution echelle Spectrometer, and Planet Finder Spectrograph high-precision Doppler measurements-and confirmed the planetary nature of the 16 day transiting candidate announced by the TESS team. We discovered an additional radial velocity signal with a period of five days induced by the presence of a second planet in the system, which we also found to transit its host star. We found that the inner mini-Neptune, TOI-421 b, has an orbital period of P-b = 5.19672 +/- 0.00049 days, a mass of M-b = 7.17 +/- 0.66 M-circle plus, and a radius of R-b = R-circle plus, whereas the outer warm Neptune, TOI-421 c, has a period of P-c = 16.06819 +/- 0.00035 days, a mass of M-c = 16.42(-1.04)(+1.06)M(circle plus), a radius of R-c = 5.09(-0.15)(+0.16)R(circle plus), and a density of rho(c) = 0.685(-0.072)(+0.080) cm(-3). With its characteristics, the outer planet (rho(c) = 0.685(-0.0072)(+0.080) cm(-3)) is placed in the intriguing class of the super-puffy mini-Neptunes. TOI-421 b and TOI-421 c are found to be well-suited for atmospheric characterization. Our atmospheric simulations predict significant Ly alpha transit absorption, due to strong hydrogen escape in both planets, as well as the presence of detectable CH4 in the atmosphere of TOI-421 c if equilibrium chemistry is assumed. ; KESPRINT collaboration, an international consortium devoted to the characterization and research of exoplanets discovered with space-based missions NASA's Science Mission directorate NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center National Aeronautics & Space Administration (NASA) European Research Council (ERC) 817540 European Research Council under the European Union's Horizon 2020 research and innovation program 832428 CRT foundation 2018.2323 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 3180246 Millennium Science Initiative, Chilean Ministry of Economy IC120009 Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1171208 Irish Research Council for Science, Engineering and Technology GOIPD/2018/659 Swedish National Space Agency DNR 65/19 136/13 Australian Research Council 170100521 NASA through Caltech/JPL grant RSA-1006130 NASA through TESS Guest Investigator Program 80NSSC19K1727 Alfred P. Sloan Foundation National Aeronautics & Space Administration (NASA) 80NSSC18K1585 80NSSC19K0379 National Science Foundation (NSF) AST1717000 Spanish Government RYC-2015-17697 FPI-SO from the Spanish Ministry of Economy and Competitiveness (MINECO) SEV-2015-0548-17-2 BES-2017-082610 National Aeronautics & Space Administration (NASA) NNX17AF27G HeisingSimons foundation PLATO grant GOLF CNES grant CONICYT-PFCHA/Doctorado Nacional, Chile 21140646 German Research Foundation (DFG) PA525/18-1 PA525/19-1 PA525/20-1 HA3279/12-1 RA714/14-1 National Aeronautics & Space Administration (NASA)

WOS: 000469975500005 ; We present the discovery of HD 221416 b, the first transiting planet identified by the Transiting Exoplanet Survey Satellite (TESS) for which asteroseismology of the host star is possible. HD 221416 b (HIP 116158, TOI-197) is a bright (V = 8.2 mag), spectroscopically classified subgiant that oscillates with an average frequency of about 430 mu Hz and displays a clear signature of mixed modes. The oscillation amplitude confirms that the redder TESS bandpass compared to Kepler has a small effect on the oscillations, supporting the expected yield of thousands of solar-like oscillators with TESS 2 minute cadence observations. Asteroseismic modeling yields a robust determination of the host star radius (R-* = 2.943 +/- 0.064 R-circle dot), mass (M-* = 1.212 +/- 0.074 M-circle dot), and age (4.9 +/- 1.1 Gyr), and demonstrates that it has just started ascending the red-giant branch. Combining asteroseismology with transit modeling and radial-velocity observations, we show that the planet is a "hot Saturn" (R-p = 9.17 +/- 0.33 R-circle plus) with an orbital period of similar to 14.3 days, irradiance of F = 343 +/- 24 F-circle plus, and moderate mass (M-p = 60.5 +/- 5.7 M-circle plus) and density (rho(p) = 0.431 +/- 0.062 g cm(-3)). The properties of HD 221416 b show that the host-star metallicity-planet mass correlation found in sub-Saturns (4-8 R-circle plus) does not extend to larger radii, indicating that planets in the transition between sub-Saturns and Jupiters follow a relatively narrow range of densities. With a density measured to similar to 15%, HD 221416 b is one of the best characterized Saturn-size planets to date, augmenting the small number of known transiting planets around evolved stars and demonstrating the power of TESS to characterize exoplanets and their host stars using asteroseismology. ; National Aeronautics and Space Administration through the TESS Guest Investigator Program [80NSSC18K1585]; National Science FoundationNational Science Foundation (NSF) [AST-1717000]; Science and Technology Facilities CouncilScience & Technology Facilities Council (STFC); UK Space Agency; European Social Fund via the Lithuanian Science Council [09.3.3-LMT-K-712-01-0103]; Danish National Research FoundationDanmarks Grundforskningsfond [DNRF106]; FONDECYT projectComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [1171208]; CONICYT projectComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) [BASAL AFB-170002]; Ministry for the Economy, Development, and Tourism's Programa Iniciativa Cientifica Milenio [IC 120009]; FONDECYTComision Nacional de Investigacion Cientifica y Tecnologica (CONICYT)CONICYT FONDECYT [3180246]; Millennium Institute of Astrophysics (MAS); MINECOSpanish Ministry of Economy & Competitiveness [ESP2017-82674-R]; AGAURAgencia de Gestio D'Ajuts Universitaris de Recerca Agaur (AGUAR) [SGR2017-1131]; PLATO grant from the CNES; European Research Council under the European Community's Seventh Framework Programme (FP72007-2013) ERC grant [338251]; European Research Council through the SPIRE grant [647383]; FCT (Portugal); FEDER through COMPETE2020 [UID/FIS/04434/2013, POCI-01-0145-FEDER-007672, PTDC/FIS-AST/30389/2017, POCI-01-0145-FEDER-030389]; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grantEuropean Union (EU) [792848]; European UnionEuropean Union (EU) [664931]; Independent Research Fund Denmark [7027-00096B]; Australian Research CouncilAustralian Research Council; NASANational Aeronautics & Space Administration (NASA) [NNX16AI09G, AS5-26555]; NSFNational Science Foundation (NSF) [AST-1514676]; Australian Research CouncilAustralian Research Council [DP150100250]; ERCEuropean Research Council (ERC) [772293]; Ramon y Cajal fellowshipMinistry of Education and Science, Spain [RYC-2015-17697]; Carlsberg FoundationCarlsberg Foundation [CF17-0760]; HBCSE-NIUS programme; NASA through Hubble Fellowship grants - Space Telescope Science Institute [HST-HF2-51399.001, HST-HF2-51424.001]; Premiale 2015 MITiC; NKFIH [K-115709]; Lendulet Program of the Hungarian Academy of Sciences [LP2018-7/2018]; NASA's Science Mission directorate ; The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawai'ian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We thank Andrei Tokovinin for helpful information on the Speckle observations obtained with SOAR. D.H. acknowledges support by the National Aeronautics and Space Administration through the TESS Guest Investigator Program (80NSSC18K1585) and by the National Science Foundation (AST-1717000). A.C. acknowledges support by the National Science Foundation under the Graduate Research Fellowship Program. W.J.C., W.H.B., A.M., O.J.H., and G.R.D. acknowledge support from the Science and Technology Facilities Council and UK Space Agency. H.K. and F.G. acknowledge support from the European Social Fund via the Lithuanian Science Council grant No. 09.3.3-LMT-K-712-01-0103. Funding for the Stellar Astrophysics Centre is provided by The Danish National Research Foundation (grant DNRF106). A.J. acknowledges support from FONDECYT project 1171208, CONICYT project BASAL AFB-170002, and by the Ministry for the Economy, Development, and Tourism's Programa Iniciativa Cientifica Milenio through grant IC 120009, awarded to the Millennium Institute of Astrophysics (MAS). R.B. acknowledges support from FONDECYT Post-doctoral Fellowship Project 3180246, and from the Millennium Institute of Astrophysics (MAS). A.M.S. is supported by grants ESP2017-82674-R (MINECO) and SGR2017-1131 (AGAUR). R.A.G. and L.B. acknowledge the support of the PLATO grant from the CNES. The research leading to the presented results has received funding from the European Research Council under the European Community's Seventh Framework Programme (FP72007-2013) ERC grant agreement No. 338251 (StellarAges). S.M. acknowledges support from the European Research Council through the SPIRE grant 647383. This work was also supported by FCT (Portugal) through national funds and by FEDER through COMPETE2020 by these grants: UID/FIS/04434/2013 and POCI-01-0145-FEDER-007672, PTDC/FIS-AST/30389/2017, and POCI-01-0145-FEDER-030389. T.L.C. acknowledges support from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 792848 (PULSATION). E.C. is funded by the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No. 664931. V.S.A. acknowledges support from the Independent Research Fund Denmark (Research grant 7027-00096B). D.S. acknowledges support from the Australian Research Council. S.B. acknowledges NASA grant NNX16AI09G and NSF grant AST-1514676. T.R.W. acknowledges support from the Australian Research Council through grant DP150100250. A.M. acknowledges support from the ERC Consolidator Grant funding scheme (project ASTEROCHRONOMETRY, G.A. n. 772293). S.M. acknowledges support from the Ramon y Cajal fellowship number RYC-2015-17697. M.S.L. is supported by the Carlsberg Foundation (grant agreement No. CF17-0760). A.M. and P.R. acknowledge support from the HBCSE-NIUS programme. J.K.T. and J.T. acknowledge that support for this work was provided by NASA through Hubble Fellowship grants HST-HF2-51399.001 and HST-HF2-51424.001 awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under contract AS5-26555. T.S.R. acknowledges financial support from Premiale 2015 MITiC (PI B. Garilli).; This project has been supported by the NKFIH K-115709 grant and the Lendulet Program of the Hungarian Academy of Sciences, project No. LP2018-7/2018.; Based on observations made with the Hertzsprung SONG telescope operated on the Spanish Observatorio del Teide on the island of Tenerife by the Aarhus and Copenhagen Universities and by the Instituto de Astrofisica de Canarias. Funding for the TESS mission is provided by NASA's Science Mission directorate. We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST).

The design and construction of CARMENES has been presented at previous SPIE conferences. It is a next-generation radial-velocity instrument at the 3.5m telescope of the Calar Alto Observatory, which was built by a consortium of eleven Spanish and German institutions. CARMENES consists of two separate échelle spectrographs covering the wavelength range from 0.52 to 1.71¿m at a spec-tral resolution of R < 80,000, fed by fibers from the Cassegrain focus of the telescope. CARMENES saw ¿First Light¿ on Nov 9, 2015. During the commissioning and initial operation phases, we established basic performance data such as throughput and spectral resolution. We found that our hollow-cathode lamps are suitable for precise wavelength calibration, but their spectra contain a number of lines of neon or argon that are so bright that the lamps cannot be used in simultaneous exposures with stars. We have therefore adopted a calibration procedure that uses simultaneous star / Fabry Pérot etalon exposures in combination with a cross-calibration between the etalons and hollow-cathode lamps during daytime. With this strategy it has been possible to achieve 1-2 m/s precision in the visible and 5-10 m/s precision in the near-IR; further improvements are expected from ongoing work on temperature control, calibration procedures and data reduction. Comparing the RV precision achieved in different wavelength bands, we find a ¿sweet spot¿ between 0.7 and 0.8¿m, where deep TiO bands provide rich RV information in mid-M dwarfs. This is in contrast to our pre-survey models, which predicted comparatively better performance in the near-IR around 1¿m, and explains in part why our near-IR RVs do not reach the same precision level as those taken with the visible spectrograph. We are now conducting a large survey of 340 nearby M dwarfs (with an average distance of only 12pc), with the goal of finding terrestrial planets in their habitable zones. We have detected the signatures of several previously known or suspected planets and also discovered several new planets. We find that the radial velocity periodograms of many M dwarfs show several significant peaks. The development of robust methods to distinguish planet signatures from activity-induced radial velocity jitter is therefore among our priorities. Due to its large wavelength coverage, the CARMENES survey is generating a unique data set for studies of M star atmospheres, rotation, and activity. The spectra cover important diagnostic lines for activity (H alpha, Na I D1 and D2, and the Ca II infrared triplet), as well as FeH lines, from which the magnetic field can be inferred. Correlating the time series of these features with each other, and with wavelength-dependent radial velocities, provides excellent handles for the discrimination between planetary companions and stellar radial velocity jitter. These data are also generating new insight into the physical properties of M dwarf atmospheres, and the impact of activity and flares on the habitability of M star planets. © 2018 SPIE. ; CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Science, the German Science Foundation through the Major Research Instrumentation Program and DFG Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia.