118 research outputs found
Weak evidence for variable occultation depth of 55 Cnc e with TESS
55 Cnc e is in a 0.73 day orbit transiting a Sun-like star. It has been
observed that the occultation depth of this Super-Earth, with a mass of
8 and radius of 2, changes significantly over
time at mid-infrared wavelengths. Observations with Spitzer measured a change
in its day-side brightness temperature of 1200 K, possibly driven by volcanic
activity, magnetic star-planet interaction, or the presence of a circumstellar
torus of dust. Previous evidence for the variability in occultation was in the
infrared range. Here we aim to explore if the variability exists also in the
optical. TESS observed 55 Cnc during sectors 21, 44 and 46. We carefully
detrend the data and fit a transit and occultation model for each sector in a
Markov Chain Monte Carlo routine. In a later stage we use the Leave-One-Out
Cross-Validation statistic to compare with a model of constant occultation for
the complete set and a model with no occultation. We report an occultation
depth of 82.5 ppm for the complete set of TESS observations. In
particular, we measured a depth of 154 ppm for sector 21, while for sector
44 we detect no occultation. In sector 46 we measure a weak occultation of
85 ppm. The occultation depth varies from one sector to the next between
1.6 and 3.4 significance. We derive the possible contribution on
reflected light and thermal emission, setting an upper limit on the geometric
albedo. Based on our model comparison the presence of an occultation is
favoured considerably over no occultation, where the model with varying
occultation across sectors takes most of the statistical weight. Our analysis
confirms a detection of the occultation in TESS. Moreover, our results weakly
lean towards a varying occultation depth between each sector, while the transit
depth is constant across visits.Comment: 9 pages, 9 figures, accepted for publication on A&
International Group for Indigenous Health Measurement: Recommendations for best practice for estimation of Indigenous mortality
AIM: To provide a best practice guide on Indigenous mortality reporting based on recommendations from the International Group for Indigenous Health Measurement.
METHOD: A workshop of the International Group for Indigenous Health Measurement was held in Montreal in 2013 during which best practices in determining Indigenous mortality were discussed. A subsequent discussion paper and draft recommendations were further refined at a meeting in Vancouver in 2014. A working group finalized this best practice guide in follow-up to the two meetings.
OUTCOME: Ten final recommendations are made regarding identification, community engagement and ownership, data linkage, uncertainty in official statistics and a timeline for implementation. In this paper we review and discuss these recommendations drawing on examples of best practice in Australia, Canada, New Zealand and the United States of America and highlighting some shortcomings in the current practices of official statistical agencies
WASP-186 and WASP-187: two hot Jupiters discovered by SuperWASP and SOPHIE with additional observations by <i>TESS</i>
We present the discovery of two new hot Jupiters identified from the WASP survey, WASP-186b and WASP-187b (TOI-1494.01 and TOI-1493.01). Their planetary nature was established from SOPHIE spectroscopic observations, and additional photometry was obtained from TESS. Stellar parameters for the host stars are derived from spectral line, IRFM, and isochrone placement analyses. These parameters are combined with the photometric and radial velocity data in an MCMC method to determine the planetary properties. WASP-186b is a massive Jupiter (4.22±0.18 MJ, 1.11 ±0.03 RJ) orbiting a mid-F star on a 5.03 day eccentric (e=0.327±0.008) orbit. WASP-187b is a low density (0.80 ±0.09 MJ, 1.64 ±0.05RJ) planet in a 5.15 day circular orbit around a slightly evolved early F-type star
Modern microwave methods in solid state inorganic materials chemistry: from fundamentals to manufacturing
No abstract available
Development of the SPECULOOS exoplanet search project
SPECULOOS (Search for habitable Planets EClipsing ULtra-cOOl Stars) aims to
perform a transit search on the nearest (pc) ultracool (K) dwarf
stars. The project's main motivation is to discover potentially habitable
planets well-suited for detailed atmospheric characterisation with upcoming
giant telescopes, like the James Webb Space Telescope (JWST) and European Large
Telescope (ELT). The project is based on a network of 1m robotic telescopes,
namely the four ones of the SPECULOOS-Southern Observatory (SSO) in Cerro
Paranal, Chile, one telescope of the SPECULOOS-Northern Observatory (SNO) in
Tenerife, and the SAINT-Ex telescope in San Pedro M\'artir, Mexico. The
prototype survey of the SPECULOOS project on the 60~cm TRAPPIST telescope
(Chile) discovered the TRAPPIST-1 system, composed of seven temperate
Earth-sized planets orbiting a nearby (12~pc) Jupiter-sized star. In this
paper, we review the current status of SPECULOOS, its first results, the plans
for its development, and its connection to the Transiting Exoplanet Survey
Satellite (TESS) and JWST
TOI-2257 b: A highly eccentric long-period sub-Neptune transiting a nearby M dwarf
Context. Thanks to the relative ease of finding and characterizing small planets around M-dwarf stars, these objects have become cornerstones in the field of exoplanet studies. The current paucity of planets in long-period orbits around M dwarfs makes such objects particularly compelling as they provide clues about the formation and evolution of these systems. Aims. In this study we present the discovery of TOI-2257 b (TIC 198485881), a long-period (35 d) sub-Neptune orbiting an M3 star at 57.8 pc. Its transit depth is about 0.4%, large enough to be detected with medium-size, ground-based telescopes. The long transit duration suggests the planet is in a highly eccentric orbit (e ∼ 0.5), which would make it the most eccentric planet known to be transiting an M-dwarf star. Methods. We combined TESS and ground-based data obtained with the 1.0-meter SAINT-EX, 0.60-meter TRAPPIST-North, and 1.2-meter FLWO telescopes to find a planetary size of 2.2 R⊕ and an orbital period of 35.19 days. In addition, we make use of archival data, high-resolution imaging, and vetting packages to support our planetary interpretation. Results. With its long period and high eccentricity, TOI-2257 b falls into a novel slice of parameter space. Despite the planet’s low equilibrium temperature (∼256 K), its host star’s small size (R∗ = 0.311 ± 0.015) and relative infrared brightness (Kmag = 10.7) make it a suitable candidate for atmospheric exploration via transmission spectroscopy.Fil: Schanche, N.. University of Bern; SuizaFil: Pozuelos, F. J.. Université de Liège; BélgicaFil: Günther, M. N.. Massachusetts Institute of Technology; Estados Unidos. Agencia Espacial Europea. European Space Research And Technology Centre.; Países BajosFil: Wells, R. D.. University of Bern; SuizaFil: Burgasser, A. J.. University of California at San Diego; Estados UnidosFil: Chinchilla, P.. Université de Liège; Bélgica. Instituto de Astrofísica de Canarias; EspañaFil: Delrez, L.. Université de Liège; BélgicaFil: Ducrot, E.. Université de Liège; BélgicaFil: Garcia, L. J.. Université de Liège; BélgicaFil: Gómez Maqueo Chew, Y.. Universidad Nacional Autónoma de México. Instituto de Astronomía; MéxicoFil: Jofre, Jorge Emiliano. Universidad Nacional Autónoma de México. Instituto de Astronomía; México. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Astronomía Teórica y Experimental. Universidad Nacional de Córdoba. Observatorio Astronómico de Córdoba. Instituto de Astronomía Teórica y Experimental; ArgentinaFil: Rackham, B. V.. Massachusetts Institute of Technology; Estados UnidosFil: Sebastian, D.. University of Birmingham; Reino UnidoFil: Stassun, K. G.. Vanderbilt University; Estados UnidosFil: Stern, D.. California Instituto Of Technology. Departament Of Mechanical And Civil Engineering; Estados UnidosFil: Timmermans, M.. Université de Liège; BélgicaFil: Barkaoui, K.. Université de Liège; Bélgica. Cadi Ayyad University; MarruecosFil: Belinski, A.. Moscow State University; RusiaFil: Benkhaldoun, Z.. Cadi Ayyad University; MarruecosFil: Benz, W.. University of Bern; SuizaFil: Bieryla, A.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Bouchy, F.. Observatorio de Ginebra; SuizaFil: Burdanov, A.. Massachusetts Institute of Technology; Estados UnidosFil: Charbonneau, D.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Christiansen, J. L.. Centro de Análisis y Procesamiento Infrarrojo; Estados Unidos. National Aeronautics and Space Administration; Estados UnidosFil: Collins, K. A.. Harvard-Smithsonian Center for Astrophysics; Estados UnidosFil: Demory, Brice Olivier. University of Bern; SuizaFil: Dévora Pajares, M.. Universidad de Granada; EspañaFil: De Wit, J.. Massachusetts Institute of Technology; Estados UnidosFil: Dragomir, D.. University of New Mexico; Estados Unido
SuperWASP dispositions and false positive catalogue
SuperWASP, the Northern hemisphere WASP observatory, has been observing the skies from La Palma since 2004. In that time, more than 50 planets have been discovered with data contributions from SuperWASP. In the process of validating planets, many false-positive candidates have also been identified. The TESS telescope is set to begin observations of the northern sky in 2019. Similar to the WASP survey, the TESS pixel size is relatively large (13 arcsec for WASP and 21 arcsec for TESS), making it susceptible to many blended signals and false detections caused principally by grazing and blended stellar eclipsing binary systems. In order to reduce duplication of effort on targets, we present a catalogue of 1 041 Northern hemisphere SuperWASP targets that have been rejected as planetary transits through follow-up observation
Two transiting hot Jupiters from the WASP survey : WASP-150b and WASP-176b
Funding: The research leading to these results has received funding from the European Research Council under the FP/2007-2013 ERC grant Agreement No. 336480 and from the ARC grant for Concerted Research Actions financed by the Wallonia-Brussels Federation. A.C.C. acknowledges support from the UK Science and Technology Facilities Council (STFC)consolidated grant No. ST/R000824/1.We report the discovery of two transiting exoplanets from the WASP survey, WASP-150b and WASP-176b. WASP-150b is an eccentric (e = 0.38) hot Jupiter on a 5.6 day orbit around a V = 12.03, F8 main-sequence host. The host star has a mass and radius of 1.4 M⊙ and 1.7 R⊙ respectively. WASP-150b has a mass and radius of 8.5 MJ and 1.1 RJ, leading to a large planetary bulk density of 6.4 ρJ. WASP-150b is found to be ~3 Gyr old, well below its circularization timescale, supporting the eccentric nature of the planet. WASP-176b is a hot Jupiter planet on a 3.9 day orbit around a V = 12.01, F9 sub-giant host. The host star has a mass and radius of 1.3 M⊙ and 1.9 R⊙. WASP-176b has a mass and radius of 0.86 MJ and 1.5 RJ, respectively, leading to a planetary bulk density of 0.23 ρJ.Publisher PDFPeer reviewe
\u3cem\u3eTESS\u3c/em\u3e Discovery Of A Sub-Neptune Orbiting A Mid-M Dwarf TOI-2136
We present the discovery of TOI-2136 b, a sub-Neptune planet transiting a nearby M4.5V-type star every 7.85 d, identified through photometric measurements from the Transiting Exoplanet Survey Satellite (TESS) mission. The host star is located 33 pc away with a radius of R* = 0.34 ± 0.02 R⊙, a mass of 0.34 ± 0.02 M⊙, and an effective temperature of 3342 ± 100 K. We estimate its stellar rotation period to be 75 ± 5 d based on archival long-term photometry. We confirm and characterize the planet based on a series of ground-based multiwavelength photometry, high-angular-resolution imaging observations, and precise radial velocities from Canada–France–Hawaii Telescope (CFHT)/SpectroPolarimètre InfraROUge (SPIRou). Our joint analysis reveals that the planet has a radius of 2.20 ± 0.17 R⊕ and a mass of 6.4 ± 2.4 M⊕. The mass and radius of TOI-2136 b are consistent with a broad range of compositions, from water-ice to gas-dominated worlds. TOI-2136 b falls close to the radius valley for M dwarfs predicted by thermally driven atmospheric mass-loss models, making it an interesting target for future studies of its interior structure and atmospheric properties
TOI-2257 b: A highly eccentric long-period sub-Neptune transiting a nearby M dwarf
N.S., R.W. and B.-O.D. acknowledge support from the Swiss National Science Foundation (PP00P2-163967 and PP00P2-190080). M.N.G. acknowledges support from MIT's Kavli Institute as a Juan Carlos Torres Fellow and from the European Space Agency (ESA) as an ESA Research Fellow. A.A.B., B.S.S.and I.A.S. acknowledge the support of the Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780 (N13.1902.21.0039). L.D. is an F.R.S.-FNRS Postdoctoral Researcher. B.V.R. thanks the Heising-Simons Foundation for support. This publication benefits from the support of the French Community of Belgium in the context of the FRIA Doctoral Grant awarded to M.T. and E.J. acknowledges DGAPA for his postdoctoral fellowship. Y.G.M.C. acknowledges support from UNAM-DGAPA PAPIIT BG-101321. D.D. acknowledges support from the TESS Guest Investigator Program grant 80NSSC19K1727 and NASA Exoplanet Research Program grant 18-2XRP18_2-0136. We acknowledge support from the Centre for Space and Habitability (CSH) of the University of Bern. Part of this work received support from the National Centre for Competence in Research PlanetS, supported by the Swiss National Science Foundation (SNSF). Funding for the TESS mission is provided by NASA's Science Mission Directorate. We acknowledge the use of public TESS 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. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. This paper includes data collected by the TESS mission that are publicly available from the Mikulski Archive for Space Telescopes (MAST). This work is based upon observations carried out at the Observatorio Astronomico Nacional on the Sierra de San Pedro Martir (OAN-SPM), Baja California, Mexico. We warmly thank the entire technical staff of the Observatorio Astronomico Nacional at San Pedro Martir in Mexico for their unfailing support to SAINT-EX operations, namely: E. Cadena, T. Calvario, E. Colorado, F. Diaz, A. Franco, B. Garcia, C. Guerrero, G. Guisa, F. Guillen, A. Landa, L. Figueroa, B. Hernandez, J. Herrera, E. Lopez, E. Lugo, B. Martinez, G. Melgoza, F. Montalvo, J.M. Nunez, J.L. Ochoa, I. Plauchu, F. Quiroz, H. Riesgo, H. Serrano, T. Verdugo, I. Zavala. The research leading to these results has received funding from the European Research Council (ERC) under the FP/2007-2013 ERC grant agreement nffi 336480, and under the European Union's Horizon 2020 research and innovation programme (grants agreements nffi 679030 and 803193/BEBOP); from an Actions de Recherche Concertee (ARC) grant, financed by the Wallonia-Brussels Federation, from the Balzan Prize Foundation, from the BEL-SPO/BRAIN2.0 research program (PORTAL project), from the Science and Technology Facilities Council (STFC; grant nffi ST/S00193X/1), and from F.R.S-FNRS (Research Project ID T010920F). This work was also partially supported by a grant from the Simons Foundation (PI: Queloz, grant number 327127), as well as by the MERAC foundation (PI: Triaud). PI: Gillon is F.R.S.-FNRS Senior Research Associate.
TRAPPIST is funded by the Belgian Fund for Scientific Research (Fond National de la Recherche Scientifique, FNRS) under the grant PDR T.0120.21, with the participation of the Swiss National Science Fundation (SNF). M.G. and E.J. are F.R.S.-FNRS Senior Research Associate. This work makes use of observations from the LCOGT network. Part of the LCOGT telescope time was granted by NOIRLab through the Mid-Scale Innovations Program (MSIP). M.S.I.P. is funded by NSF. Some of the observations in the paper made use of the High-Resolution Imaging instrument(s) `Alopeke (and/or Zorro). `Alopeke (and/or Zorro) was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. Data were reduced using a software pipeline originally written by Elliott Horch and Mark Everett. `Alopeke (and/or Zorro) was mounted on the Gemini North (and/or South) telescope of the international Gemini Observatory, a program of NSF's OIR Lab, which is managed by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation, on behalf of the Gemini partnership: the National Science Foundation (United States), National Research Council (Canada), Agencia Nacional de Investigacion y Desarrollo (Chile), Ministerio de Ciencia, Tecnologia e Innovacion (Argentina), Ministerio da Ciencia, Tecnologia, Inovacoes e Comunicacoes (Brazil), and Korea Astronomy and Space Science Institute (Republic of Korea). This research has made use of the NASA Exoplanet Archive, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This research made use of exoplanet (Foreman-Mackey et al. 2021a,b) and its dependencies (Agol et al. 2020; Kumar et al. 2019; Astropy Collaboration 2013, 2018; Kipping 2013; Luger et al. 2019; Salvatier et al. 2016; Theano Development Team 2016). Additional use of software packages AstroImageJ (Collins et al. 2017) and TAPIR (Jensen 2013).Context. Thanks to the relative ease of finding and characterizing small planets around M-dwarf stars, these objects have become cornerstones in the field of exoplanet studies. The current paucity of planets in long-period orbits around M dwarfs makes such objects particularly compelling as they provide clues about the formation and evolution of these systems.
Aims. In this study we present the discovery of TOI-2257 b (TIC 198485881), a long-period (35 d) sub-Neptune orbiting an M3 star at 57.8 pc. Its transit depth is about 0.4%, large enough to be detected with medium-size, ground-based telescopes. The long transit duration suggests the planet is in a highly eccentric orbit (e similar to 0.5), which would make it the most eccentric planet known to be transiting an M-dwarf star.
Methods. We combined TESS and ground-based data obtained with the 1.0-meter SAINT-EX, 0.60-meter TRAPPIST-North, and 1.2-meter FLWO telescopes to find a planetary size of 2.2 R-circle plus and an orbital period of 35.19 days. In addition, we make use of archival data, high-resolution imaging, and vetting packages to support our planetary interpretation.
Results. With its long period and high eccentricity, TOI-2257 b falls into a novel slice of parameter space. Despite the planet's low equilibrium temperature (similar to 256 K), its host star's small size (R-* = 0.311 +/- 0.015) and relative infrared brightness (K-mag = 10.7) make it a suitable candidate for atmospheric exploration via transmission spectroscopy.Swiss National Science Foundation (SNSF)European Commission PP00P2-163967
PP00P2-190080MIT's Kavli InstituteEuropean Space Agency
European CommissionMinistry of Science and Higher Education of the Russian Federation 075-15-2020-780 (N13.1902.21.0039)Heising-Simons FoundationFrench Community of BelgiumDGAPAPrograma de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica (PAPIIT)
Universidad Nacional Autonoma de Mexico BG-101321TESS Guest Investigator Program 80NSSC19K1727NASA Exoplanet Research Program 18-2XRP18_2-0136Centre for Space and Habitability (CSH) of the University of BernSwiss National Science Foundation (SNSF)European Research Council (ERC) 336480Actions de Recherche Concertee (ARC) grant - Wallonia-Brussels FederationUK Research & Innovation (UKRI)Science & Technology Facilities Council (STFC)Science and Technology Development Fund (STDF) ST/S00193X/1Fonds de la Recherche Scientifique - FNRS T010920FSimons Foundation 327127MERAC foundationFonds de la Recherche Scientifique - FNRS PDR T.0120.21Swiss National Science Foundation (SNSF)National Science Foundation (NSF)NASA Exoplanet Exploration Program
NASA's Science Mission DirectorateEuropean Research Council (ERC) 679030
803193/BEBOPBalzan Prize Foundation
BEL-SPO/BRAIN2.0 research program (PORTAL project
- …