ALBERT

Description: In regions where aquifers sustain rivers, the location and quantification of groundwater discharge to surface water are important to prevent pollution hazards, to quantify and predict low flows and to manage water supplies. 222 Rn is commonly used to determine groundwater discharge to rivers. However, using this isotopic tracer is challenging because of the high diffusion capacity of 222 Rn in open water. This study illustrates how a combination of isotopic tracers can contribute to an enhanced understanding of groundwater discharge patterns in small rivers. The aim of this paper is to combine 222 Rn and δ 13 C DIC to better constrain the physical parameters related to the degassing process of these tracers in rivers. The Hallue River (northern France) was targeted for this study because it is sustained almost exclusively by a fractured chalk aquifer. The isotopes 222 Rn, δ 13 C DIC , δ 2 H and δ 18 O were analyzed along with other natural geochemical tracers. A mass balance model was used to simulate 222 Rn and δ 13 C DIC . The results of δ 2 H and δ 18 O analyses prove that evaporation did not occur in the river. The calibration of a numerical model to reproduce 222 Rn and δ 13 C DIC provides a best-fit diffusive layer thickness of 3.21x10 −5  m. This approach is particularly useful for small rivers flowing over carbonate aquifers with high groundwater DIC where the evolution of river DIC reflects the competing processes of groundwater inflow and CO 2 degassing. This approach provides a means to evaluate groundwater discharge in small ungauged rivers. This article is protected by copyright. All rights reserved.

Description: The 'hot Jupiters' that abound in lists of known extrasolar planets are thought to have formed far from their host stars, but migrate inwards through interactions with the proto-planetary disk from which they were born, or by an alternative mechanism such as planet-planet scattering. The hot Jupiters closest to their parent stars, at orbital distances of only approximately 0.02 astronomical units, have strong tidal interactions, and systems such as OGLE-TR-56 have been suggested as tests of tidal dissipation theory. Here we report the discovery of planet WASP-18b with an orbital period of 0.94 days and a mass of ten Jupiter masses (10 M(Jup)), resulting in a tidal interaction an order of magnitude stronger than that of planet OGLE-TR-56b. Under the assumption that the tidal-dissipation parameter Q of the host star is of the order of 10(6), as measured for Solar System bodies and binary stars and as often applied to extrasolar planets, WASP-18b will be spiralling inwards on a timescale less than a thousandth that of the lifetime of its host star. Therefore either WASP-18 is in a rare, exceptionally short-lived state, or the tidal dissipation in this system (and possibly other hot-Jupiter systems) must be much weaker than in the Solar System.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hellier, Coel -- Anderson, D R -- Cameron, A Collier -- Gillon, M -- Hebb, L -- Maxted, P F L -- Queloz, D -- Smalley, B -- Triaud, A H M J -- West, R G -- Wilson, D M -- Bentley, S J -- Enoch, B -- Horne, K -- Irwin, J -- Lister, T A -- Mayor, M -- Parley, N -- Pepe, F -- Pollacco, D L -- Segransan, D -- Udry, S -- Wheatley, P J -- England -- Nature. 2009 Aug 27;460(7259):1098-100. doi: 10.1038/nature08245.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrophysics Group, Keele University, Staffordshire, ST5 5BG, UK. ch@astro.keele.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19713926" target="_blank"〉PubMed〈/a〉

Description: Of the over 400 known exoplanets, there are about 70 planets that transit their central star, a situation that permits the derivation of their basic parameters and facilitates investigations of their atmospheres. Some short-period planets, including the first terrestrial exoplanet (CoRoT-7b), have been discovered using a space mission designed to find smaller and more distant planets than can be seen from the ground. Here we report transit observations of CoRoT-9b, which orbits with a period of 95.274 days on a low eccentricity of 0.11 +/- 0.04 around a solar-like star. Its periastron distance of 0.36 astronomical units is by far the largest of all transiting planets, yielding a 'temperate' photospheric temperature estimated to be between 250 and 430 K. Unlike previously known transiting planets, the present size of CoRoT-9b should not have been affected by tidal heat dissipation processes. Indeed, the planet is found to be well described by standard evolution models with an inferred interior composition consistent with that of Jupiter and Saturn.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Deeg, H J -- Moutou, C -- Erikson, A -- Csizmadia, Sz -- Tingley, B -- Barge, P -- Bruntt, H -- Havel, M -- Aigrain, S -- Almenara, J M -- Alonso, R -- Auvergne, M -- Baglin, A -- Barbieri, M -- Benz, W -- Bonomo, A S -- Borde, P -- Bouchy, F -- Cabrera, J -- Carone, L -- Carpano, S -- Ciardi, D -- Deleuil, M -- Dvorak, R -- Ferraz-Mello, S -- Fridlund, M -- Gandolfi, D -- Gazzano, J-C -- Gillon, M -- Gondoin, P -- Guenther, E -- Guillot, T -- den Hartog, R -- Hatzes, A -- Hidas, M -- Hebrard, G -- Jorda, L -- Kabath, P -- Lammer, H -- Leger, A -- Lister, T -- Llebaria, A -- Lovis, C -- Mayor, M -- Mazeh, T -- Ollivier, M -- Patzold, M -- Pepe, F -- Pont, F -- Queloz, D -- Rabus, M -- Rauer, H -- Rouan, D -- Samuel, B -- Schneider, J -- Shporer, A -- Stecklum, B -- Street, R -- Udry, S -- Weingrill, J -- Wuchterl, G -- England -- Nature. 2010 Mar 18;464(7287):384-7. doi: 10.1038/nature08856.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Instituto de Astrofisica de Canarias, C. Via Lactea S/N, E-38205 La Laguna, Tenerife, Spain. hdeeg@iac.es〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/20237564" target="_blank"〉PubMed〈/a〉

Description: Pluto and Eris are icy dwarf planets with nearly identical sizes, comparable densities and similar surface compositions as revealed by spectroscopic studies. Pluto possesses an atmosphere whereas Eris does not; the difference probably arises from their differing distances from the Sun, and explains their different albedos. Makemake is another icy dwarf planet with a spectrum similar to Eris and Pluto, and is currently at a distance to the Sun intermediate between the two. Although Makemake's size (1,420 +/- 60 km) and albedo are roughly known, there has been no constraint on its density and there were expectations that it could have a Pluto-like atmosphere. Here we report the results from a stellar occultation by Makemake on 2011 April 23. Our preferred solution that fits the occultation chords corresponds to a body with projected axes of 1,430 +/- 9 km (1sigma) and 1,502 +/- 45 km, implying a V-band geometric albedo p(V) = 0.77 +/- 0.03. This albedo is larger than that of Pluto, but smaller than that of Eris. The disappearances and reappearances of the star were abrupt, showing that Makemake has no global Pluto-like atmosphere at an upper limit of 4-12 nanobar (1sigma) for the surface pressure, although a localized atmosphere is possible. A density of 1.7 +/- 0.3 g cm(-3) is inferred from the data.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ortiz, J L -- Sicardy, B -- Braga-Ribas, F -- Alvarez-Candal, A -- Lellouch, E -- Duffard, R -- Pinilla-Alonso, N -- Ivanov, V D -- Littlefair, S P -- Camargo, J I B -- Assafin, M -- Unda-Sanzana, E -- Jehin, E -- Morales, N -- Tancredi, G -- Gil-Hutton, R -- de la Cueva, I -- Colque, J P -- Da Silva Neto, D N -- Manfroid, J -- Thirouin, A -- Gutierrez, P J -- Lecacheux, J -- Gillon, M -- Maury, A -- Colas, F -- Licandro, J -- Mueller, T -- Jacques, C -- Weaver, D -- Milone, A -- Salvo, R -- Bruzzone, S -- Organero, F -- Behrend, R -- Roland, S -- Vieira-Martins, R -- Widemann, T -- Roques, F -- Santos-Sanz, P -- Hestroffer, D -- Dhillon, V S -- Marsh, T R -- Harlingten, C -- Bagatin, A Campo -- Alonso, M L -- Ortiz, M -- Colazo, C -- Lima, H J F -- Oliveira, A S -- Kerber, L O -- Smiljanic, R -- Pimentel, E -- Giacchini, B -- Cacella, P -- Emilio, M -- England -- Nature. 2012 Nov 22;491(7425):566-9. doi: 10.1038/nature11597.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Instituto de Astrofisica de Andalucia, CSIC, Apartado 3004, 18080 Granada, Spain. ortiz@iaa.es〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/23172214" target="_blank"〉PubMed〈/a〉

Description: Hitherto, rings have been found exclusively around the four giant planets in the Solar System. Rings are natural laboratories in which to study dynamical processes analogous to those that take place during the formation of planetary systems and galaxies. Their presence also tells us about the origin and evolution of the body they encircle. Here we report observations of a multichord stellar occultation that revealed the presence of a ring system around (10199) Chariklo, which is a Centaur--that is, one of a class of small objects orbiting primarily between Jupiter and Neptune--with an equivalent radius of 124 +/- 9 kilometres (ref. 2). There are two dense rings, with respective widths of about 7 and 3 kilometres, optical depths of 0.4 and 0.06, and orbital radii of 391 and 405 kilometres. The present orientation of the ring is consistent with an edge-on geometry in 2008, which provides a simple explanation for the dimming of the Chariklo system between 1997 and 2008, and for the gradual disappearance of ice and other absorption features in its spectrum over the same period. This implies that the rings are partly composed of water ice. They may be the remnants of a debris disk, possibly confined by embedded, kilometre-sized satellites.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Braga-Ribas, F -- Sicardy, B -- Ortiz, J L -- Snodgrass, C -- Roques, F -- Vieira-Martins, R -- Camargo, J I B -- Assafin, M -- Duffard, R -- Jehin, E -- Pollock, J -- Leiva, R -- Emilio, M -- Machado, D I -- Colazo, C -- Lellouch, E -- Skottfelt, J -- Gillon, M -- Ligier, N -- Maquet, L -- Benedetti-Rossi, G -- Ramos Gomes, A Jr -- Kervella, P -- Monteiro, H -- Sfair, R -- El Moutamid, M -- Tancredi, G -- Spagnotto, J -- Maury, A -- Morales, N -- Gil-Hutton, R -- Roland, S -- Ceretta, A -- Gu, S-h -- Wang, X-b -- Harpsoe, K -- Rabus, M -- Manfroid, J -- Opitom, C -- Vanzi, L -- Mehret, L -- Lorenzini, L -- Schneiter, E M -- Melia, R -- Lecacheux, J -- Colas, F -- Vachier, F -- Widemann, T -- Almenares, L -- Sandness, R G -- Char, F -- Perez, V -- Lemos, P -- Martinez, N -- Jorgensen, U G -- Dominik, M -- Roig, F -- Reichart, D E -- LaCluyze, A P -- Haislip, J B -- Ivarsen, K M -- Moore, J P -- Frank, N R -- Lambas, D G -- England -- Nature. 2014 Apr 3;508(7494):72-5. doi: 10.1038/nature13155. Epub 2014 Mar 26.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Observatorio Nacional/MCTI, Rua General Jose Cristino 77, CEP 20921-400 Rio de Janeiro, RJ, Brazil. ; LESIA, Observatoire de Paris, CNRS UMR 8109, Universite Pierre et Marie Curie, Universite Paris-Diderot, 5 place Jules Janssen, F-92195 Meudon Cedex, France. ; Instituto de Astrofisica de Andalucia, CSIC, Apartado 3004, 18080 Granada, Spain. ; Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Gottingen, Germany. ; 1] Observatorio Nacional/MCTI, Rua General Jose Cristino 77, CEP 20921-400 Rio de Janeiro, RJ, Brazil [2] Observatorio do Valongo/UFRJ, Ladeira Pedro Antonio 43, CEP 20.080-090 Rio de Janeiro, RJ, Brazil [3] Observatoire de Paris, IMCCE, UPMC, CNRS, 77 Avenue Denfert-Rochereau, 75014 Paris, France. ; Observatorio do Valongo/UFRJ, Ladeira Pedro Antonio 43, CEP 20.080-090 Rio de Janeiro, RJ, Brazil. ; Institut d'Astrophysique de l'Universite de Liege, Allee du 6 Aout 17, B-4000 Liege, Belgium. ; Physics and Astronomy Department, Appalachian State University, Boone, North Carolina 28608, USA. ; Instituto de Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Avenida Vicuna Mackenna 4860, Santiago 7820436, Chile. ; Universidade Estadual de Ponta Grossa, O.A. - DEGEO, Avenida Carlos Cavalcanti 4748, Ponta Grossa 84030-900, PR, Brazil. ; 1] Polo Astronomico Casimiro Montenegro Filho/FPTI-BR, Avenida Tancredo Neves 6731, CEP 85867-900, Foz do Iguacu, PR, Brazil [2] Universidade Estadual do Oeste do Parana (Unioeste), Avenda Tarquinio Joslin dos Santos, 1300, CEP 85870-650, Foz do Iguacu, PR, Brazil. ; 1] Ministerio de Educacion de la Provincia de Cordoba, Santa Rosa 751, Cordoba 5000, Argentina [2] Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, Cordoba 5000, Argentina. ; 1] Niels Bohr Institute, University of Copenhagen, Juliane Maries vej 30, 2100 Copenhagen, Denmark [2] Centre for Star and Planet Formation, Geological Museum, Oster Voldgade 5, 1350 Copenhagen, Denmark. ; Instituto de Fisica e Quimica, Avenida BPS 1303, CEP 37500-903, Itajuba, MG, Brazil. ; UNESP - Universidade Estadual Paulista, Avenida Ariberto Pereira da Cunha, 333, CEP 12516-410 Guaratingueta, SP, Brazil. ; 1] LESIA, Observatoire de Paris, CNRS UMR 8109, Universite Pierre et Marie Curie, Universite Paris-Diderot, 5 place Jules Janssen, F-92195 Meudon Cedex, France [2] Observatoire de Paris, IMCCE, UPMC, CNRS, 77 Avenue Denfert-Rochereau, 75014 Paris, France. ; 1] Observatorio Astronomico Los Molinos, DICYT, MEC, 12400 Montevideo, Uruguay [2] Departamento de Astronomia, Facultad Ciencias, Universidad de la Republica, 11300 Montevideo, Uruguay. ; Observatorio El Catalejo, Mussio 255, Santa Rosa, La Pampa 6300, Argentina. ; San Pedro de Atacama Celestial Explorations, Casilla 21, San Pedro de Atacama 1410000, Chile. ; Complejo Astronomico El Leoncito (CASLEO) and San Juan National University, Avenida Espana 1512 sur, J5402DSP, San Juan, Argentina. ; Observatorio Astronomico Los Molinos, DICYT, MEC, 12400 Montevideo, Uruguay. ; 1] Departamento de Astronomia, Facultad Ciencias, Universidad de la Republica, 11300 Montevideo, Uruguay [2] Observatorio del IPA, Consejo de Formacion en Educacion, 11800 Montevideo, Uruguay. ; 1] Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, China [2] Key Laboratory for the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011, China. ; 1] Instituto de Astrofisica, Facultad de Fisica, Pontificia Universidad Catolica de Chile, Avenida Vicuna Mackenna 4860, Santiago 7820436, Chile [2] Max Planck Institute for Astronomy, Konigstuhl 17, 69117 Heidelberg, Germany. ; Department of Electrical Engineering and Center of Astro-Engineering, Pontificia Universidad Catolica de Chile, Avenida Vicuna Mackenna 4860, Santiago 7820436, Chile. ; Polo Astronomico Casimiro Montenegro Filho/FPTI-BR, Avenida Tancredo Neves 6731, CEP 85867-900, Foz do Iguacu, PR, Brazil. ; 1] Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, Cordoba 5000, Argentina [2] Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Cordoba 5000, Argentina [3] Instituto de Astronomia Teorica y Experimental IATE-CONICET, Cordoba 5000, Argentina [4] Facultad de Ciencias Exactas, Fisicas y Naturales, Universidad Nacional de Cordoba (UNC), Cordoba 5000, Argentina. ; Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, Cordoba 5000, Argentina. ; Observatoire de Paris, IMCCE, UPMC, CNRS, 77 Avenue Denfert-Rochereau, 75014 Paris, France. ; Unidad de Astronomia, Facultad de Ciencias Basicas, Universidad de Antofagasta, Avenida Angamos 601, Antofagasta, Region II, Chile. ; Departamento de Astronomia, Facultad Ciencias, Universidad de la Republica, 11300 Montevideo, Uruguay. ; Scottish Universities Physics Alliance, University of St Andrews, School of Physics and Astronomy, North Haugh, St Andrews KY16 9SS, UK. ; Department of Physics and Astronomy, University of North Carolina - Chapel Hill, North Carolina 27599, USA. ; 1] Observatorio Astronomico, Universidad Nacional de Cordoba, Laprida 854, Cordoba 5000, Argentina [2] Instituto de Astronomia Teorica y Experimental IATE-CONICET, Cordoba 5000, Argentina.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/24670644" target="_blank"〉PubMed〈/a〉

Description: The dwarf planet Eris is a trans-Neptunian object with an orbital eccentricity of 0.44, an inclination of 44 degrees and a surface composition very similar to that of Pluto. It resides at present at 95.7 astronomical units (1 AU is the Earth-Sun distance) from Earth, near its aphelion and more than three times farther than Pluto. Owing to this great distance, measuring its size or detecting a putative atmosphere is difficult. Here we report the observation of a multi-chord stellar occultation by Eris on 6 November 2010 UT. The event is consistent with a spherical shape for Eris, with radius 1,163 +/- 6 kilometres, density 2.52 +/- 0.05 grams per cm(3) and a high visible geometric albedo, Pv = 0.96(+0.09)(-0.04). No nitrogen, argon or methane atmospheres are detected with surface pressure larger than approximately 1 nanobar, about 10,000 times more tenuous than Pluto's present atmosphere. As Pluto's radius is estimated to be between 1,150 and 1,200 kilometres, Eris appears as a Pluto twin, with a bright surface possibly caused by a collapsed atmosphere, owing to its cold environment. We anticipate that this atmosphere may periodically sublimate as Eris approaches its perihelion, at 37.8 astronomical units from the Sun.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sicardy, B -- Ortiz, J L -- Assafin, M -- Jehin, E -- Maury, A -- Lellouch, E -- Hutton, R Gil -- Braga-Ribas, F -- Colas, F -- Hestroffer, D -- Lecacheux, J -- Roques, F -- Santos-Sanz, P -- Widemann, T -- Morales, N -- Duffard, R -- Thirouin, A -- Castro-Tirado, A J -- Jelinek, M -- Kubanek, P -- Sota, A -- Sanchez-Ramirez, R -- Andrei, A H -- Camargo, J I B -- da Silva Neto, D N -- Gomes, A Ramos Jr -- Martins, R Vieira -- Gillon, M -- Manfroid, J -- Tozzi, G P -- Harlingten, C -- Saravia, S -- Behrend, R -- Mottola, S -- Melendo, E Garcia -- Peris, V -- Fabregat, J -- Madiedo, J M -- Cuesta, L -- Eibe, M T -- Ullan, A -- Organero, F -- Pastor, S -- de Los Reyes, J A -- Pedraz, S -- Castro, A -- de la Cueva, I -- Muler, G -- Steele, I A -- Cebrian, M -- Montanes-Rodriguez, P -- Oscoz, A -- Weaver, D -- Jacques, C -- Corradi, W J B -- Santos, F P -- Reis, W -- Milone, A -- Emilio, M -- Gutierrez, L -- Vazquez, R -- Hernandez-Toledo, H -- England -- Nature. 2011 Oct 26;478(7370):493-6. doi: 10.1038/nature10550.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉LESIA-Observatoire de Paris, CNRS, Universite Pierre et Marie Curie, Universite Paris-Diderot, 11, Rue Marcelin Berthelot, 92195 Meudon cedex, France. bruno.sicardy@obspm.fr〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/22031441" target="_blank"〉PubMed〈/a〉

Description: Star-like objects with effective temperatures of less than 2,700 kelvin are referred to as 'ultracool dwarfs'. This heterogeneous group includes stars of extremely low mass as well as brown dwarfs (substellar objects not massive enough to sustain hydrogen fusion), and represents about 15 per cent of the population of astronomical objects near the Sun. Core-accretion theory predicts that, given the small masses of these ultracool dwarfs, and the small sizes of their protoplanetary disks, there should be a large but hitherto undetected population of terrestrial planets orbiting them--ranging from metal-rich Mercury-sized planets to more hospitable volatile-rich Earth-sized planets. Here we report observations of three short-period Earth-sized planets transiting an ultracool dwarf star only 12 parsecs away. The inner two planets receive four times and two times the irradiation of Earth, respectively, placing them close to the inner edge of the habitable zone of the star. Our data suggest that 11 orbits remain possible for the third planet, the most likely resulting in irradiation significantly less than that received by Earth. The infrared brightness of the host star, combined with its Jupiter-like size, offers the possibility of thoroughly characterizing the components of this nearby planetary system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gillon, Michael -- Jehin, Emmanuel -- Lederer, Susan M -- Delrez, Laetitia -- de Wit, Julien -- Burdanov, Artem -- Van Grootel, Valerie -- Burgasser, Adam J -- Triaud, Amaury H M J -- Opitom, Cyrielle -- Demory, Brice-Olivier -- Sahu, Devendra K -- Bardalez Gagliuffi, Daniella -- Magain, Pierre -- Queloz, Didier -- England -- Nature. 2016 May 2;533(7602):221-4. doi: 10.1038/nature17448.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut d'Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout 19C, 4000 Liege, Belgium. ; NASA Johnson Space Center, 2101 NASA Parkway, Houston, Texas, 77058, USA. ; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Center for Astrophysics and Space Science, University of California San Diego, La Jolla, California 92093, USA. ; Institute of Astronomy, Madingley Road, Cambridge CB3 0HA, UK. ; Astrophysics Group, Cavendish Laboratory, 19 J J Thomson Avenue, Cambridge, CB3 0HE, UK. ; Indian Institute of Astrophysics, Koramangala, Bangalore 560 034, India.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27135924" target="_blank"〉PubMed〈/a〉

Description: Over the past decade, observations of giant exoplanets (Jupiter-size) have provided key insights into their atmospheres, but the properties of lower-mass exoplanets (sub-Neptune) remain largely unconstrained because of the challenges of observing small planets. Numerous efforts to observe the spectra of super-Earths--exoplanets with masses of one to ten times that of Earth--have so far revealed only featureless spectra. Here we report a longitudinal thermal brightness map of the nearby transiting super-Earth 55 Cancri e (refs 4, 5) revealing highly asymmetric dayside thermal emission and a strong day-night temperature contrast. Dedicated space-based monitoring of the planet in the infrared revealed a modulation of the thermal flux as 55 Cancri e revolves around its star in a tidally locked configuration. These observations reveal a hot spot that is located 41 +/- 12 degrees east of the substellar point (the point at which incident light from the star is perpendicular to the surface of the planet). From the orbital phase curve, we also constrain the nightside brightness temperature of the planet to 1,380 +/- 400 kelvin and the temperature of the warmest hemisphere (centred on the hot spot) to be about 1,300 kelvin hotter (2,700 +/- 270 kelvin) at a wavelength of 4.5 micrometres, which indicates inefficient heat redistribution from the dayside to the nightside. Our observations are consistent with either an optically thick atmosphere with heat recirculation confined to the planetary dayside, or a planet devoid of atmosphere with low-viscosity magma flows at the surface.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Demory, Brice-Olivier -- Gillon, Michael -- de Wit, Julien -- Madhusudhan, Nikku -- Bolmont, Emeline -- Heng, Kevin -- Kataria, Tiffany -- Lewis, Nikole -- Hu, Renyu -- Krick, Jessica -- Stamenkovic, Vlada -- Benneke, Bjorn -- Kane, Stephen -- Queloz, Didier -- England -- Nature. 2016 Apr 14;532(7598):207-9. doi: 10.1038/nature17169. Epub 2016 Mar 30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Astrophysics Group, Cavendish Laboratory, JJ Thomson Avenue, Cambridge CB3 0HE, UK. ; Institut d'Astrophysique et de Geophysique, Universite of Liege, allee du 6 Aout 17, 4000 Liege, Belgium. ; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Institute of Astronomy, University of Cambridge, Cambridge CB3 0HA, UK. ; NaXys, Department of Mathematics, University of Namur, 8 Rempart de la Vierge, 5000 Namur, Belgium. ; University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012, Bern, Switzerland. ; Astrophysics Group, School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL, UK. ; Space Telescope Science Institute, Baltimore, Maryland 21218, USA. ; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA. ; Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA. ; Spitzer Science Center, MS 220-6, California Institute of Technology, Jet Propulsion Laboratory, Pasadena, California 91125, USA. ; Department of Physics and Astronomy, San Francisco State University, 1600 Holloway Avenue, San Francisco, California 94132, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/27027283" target="_blank"〉PubMed〈/a〉

Description: M-dwarf stars--hydrogen-burning stars that are smaller than 60 per cent of the size of the Sun--are the most common class of star in our Galaxy and outnumber Sun-like stars by a ratio of 12:1. Recent results have shown that M dwarfs host Earth-sized planets in great numbers: the average number of M-dwarf planets that are between 0.5 to 1.5 times the size of Earth is at least 1.4 per star. The nearest such planets known to transit their star are 39 parsecs away, too distant for detailed follow-up observations to measure the planetary masses or to study their atmospheres. Here we report observations of GJ 1132b, a planet with a size of 1.2 Earth radii that is transiting a small star 12 parsecs away. Our Doppler mass measurement of GJ 1132b yields a density consistent with an Earth-like bulk composition, similar to the compositions of the six known exoplanets with masses less than six times that of the Earth and precisely measured densities. Receiving 19 times more stellar radiation than the Earth, the planet is too hot to be habitable but is cool enough to support a substantial atmosphere, one that has probably been considerably depleted of hydrogen. Because the host star is nearby and only 21 per cent the radius of the Sun, existing and upcoming telescopes will be able to observe the composition and dynamics of the planetary atmosphere.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berta-Thompson, Zachory K -- Irwin, Jonathan -- Charbonneau, David -- Newton, Elisabeth R -- Dittmann, Jason A -- Astudillo-Defru, Nicola -- Bonfils, Xavier -- Gillon, Michael -- Jehin, Emmanuel -- Stark, Antony A -- Stalder, Brian -- Bouchy, Francois -- Delfosse, Xavier -- Forveille, Thierry -- Lovis, Christophe -- Mayor, Michel -- Neves, Vasco -- Pepe, Francesco -- Santos, Nuno C -- Udry, Stephane -- Wunsche, Anael -- England -- Nature. 2015 Nov 12;527(7577):204-7. doi: 10.1038/nature15762.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA. ; Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA. ; Observatoire de Geneve, Universite de Geneve, 51 chemin des Maillettes, 1290 Sauverny, Switzerland. ; Universite Grenoble Alpes, IPAG, F-38000 Grenoble, France. ; CNRS, IPAG, F-38000 Grenoble, France. ; Institut d'Astrophysique et de Geophysique, Universite de Liege, Allee du 6 Aout 17, Batiment B5C, 4000 Liege, Belgium. ; Institute for Astronomy, University of Hawaii at Manoa, Honolulu, Hawaii 96822, USA. ; Laboratoire d'Astrophysique de Marseille, UMR 6110 CNRS, Universite de Provence, 38 rue Frederic Joliot-Curie, 13388, Marseille Cedex 13, France. ; Departamento de Fisica, Universidade Federal do Rio Grande do Norte, 59072-970 Natal, Rio Grande do Norte, Brazil. ; Instituto de Astrofisica e Ciencias do Espaco, Universidade do Porto, CAUP, Rua das Estrelas, 4150-762 Porto, Portugal. ; Departamento de Fisica e Astronomia, Faculdade de Ciencias, Universidade do Porto, Rua Campo Alegre, 4169-007 Porto, Portugal.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26560298" target="_blank"〉PubMed〈/a〉

Description: Results from exoplanet surveys indicate that small planets (super-Earth size and below) are abundant in our Galaxy. However, little is known about their interiors and atmospheres. There is therefore a need to find small planets transiting bright stars, which would enable a detailed characterization of this population of objects. We present the results of a search for the transit of the Earth-mass exoplanet α Centauri B b with the Hubble Space Telescope ( HST ). We observed α Centauri B twice in 2013 and 2014 for a total of 40 h. We achieve a precision of 115 ppm per 6-s exposure time in a highly saturated regime, which is found to be consistent across HST orbits. We rule out the transiting nature of α Centauri B b with the orbital parameters published in the literature at 96.6 per cent confidence. We find in our data a single transit-like event that could be associated with another Earth-sized planet in the system, on a longer period orbit. Our programme demonstrates the ability of HST to obtain consistent, high-precision photometry of saturated stars over 26 h of continuous observations.