The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars

The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520–1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700–900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s−1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3–4 m s−1

The CARMENES search for exoplanets around M dwarfs HD147379 b: A nearby Neptune in the temperate zone of an early-M dwarf

We report on the first star discovered to host a planet detected by radial velocity (RV) observations obtained within the CARMENES survey for exoplanets around M dwarfs. HD 147379 (V = 8.9 mag, M = 0.58 ± 0.08 M⊙), a bright M0.0 V star at a distance of 10.7 pc, is found to undergo periodic RV variations with a semi-amplitude of K = 5.1 ± 0.4 m s−1 and a period of P = 86.54 ± 0.06 d. The RV signal is found in our CARMENES data, which were taken between 2016 and 2017, and is supported by HIRES/Keck observations that were obtained since 2000. The RV variations are interpreted as resulting from a planet of minimum mass mP sin i = 25 ± 2 M⊕, 1.5 times the mass of Neptune, with an orbital semi-major axis a = 0.32 au and low eccentricity (e < 0.13). HD 147379 b is orbiting inside the temperate zone around the star, where water could exist in liquid form. The RV time-series and various spectroscopic indicators show additional hints of variations at an approximate period of 21.1 d (and its first harmonic), which we attribute to the rotation period of the star.FEDER/ERF FICTS-2011-02 fundsMajor Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red StarsEuropean Research Council (ERC-279347), Deutsche Forschungsgemeinschaft (RE 1664/12-1, RE 2694/4-1), Bundesministerium für Bildung und Forschung (BMBF-05A14MG3, BMBF-05A17MG3), Spanish Ministry of Economy and Competitiveness (MINECO, grants AYA2015-68012-C2-2-P, AYA2016-79425-C3-1,2,3-P, AYA2015-69350-C3-2-P, AYA2014-54348-C03- 01, AYA2014-56359-P, AYA2014-54348-C3-2-R, AYA2016-79425-C3-3-P and 2013 Ramòn y Cajal program RYC-2013-14875), Fondo Europeo de Desarrollo Regional (FEDER, grant ESP2016-80435-C2-1-R, ESP2015-65712-C5- 5-R), Generalitat de Catalunya/CERCA programme, Spanish Ministerio de Educación, Cultura y Deporte, programa de Formación de Profesorado Universitario (grant FPU15/01476), Deutsches Zentrum für Luft- und Raumfahrt (grants 50OW0204 and 50OO1501), Office of Naval Research Global (award no. N62909-15-1-2011), Mexican CONACyT grant CB-2012-183007

The CARMENES search for exoplanets around M dwarfs High-resolution optical and near-infrared spectroscopy of 324 survey stars

The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520–1710 nm at a resolution of at least R >80 000, and we measure its RV, Hα emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700–900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s−1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3–4 m s−1

The CARMENES search for exoplanets around M dwarfs. First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems

Stars and planetary system

CARMENES: high-resolution spectra and precise radial velocities in the red and infrared

SPIE Astronomical Telescopes + Instrumentation (2018, Austin, Texas, United States

Acceptability and prerequisites for the successful introduction of sturgeon species

International audienceThis study aims to synthesise the documented examples of sturgeon introductions worldwide, to pinpoint the prerequisites for success. Introductions lation and re-introduction are of concern. Our analysis enables us to classify the prerequisites for successful introduction according to the following five criteria: (1) geography, (2) habitat, (3) species-specific, (4) restocking, and (5) management. Co-managing and monitoring programmes applied to the introduction of a small number of tagged juveniles into suitable habitats of a small water system of a single country are promising conditions for success. In any case, introductions are multidisciplinary actions, which need to be mobilised in a coordinated fashion to set up clear objectives and hypotheses and take all the measures needed to verify each step of the introduction programmes

Acipenser sturio recovery research actions in France

International audienceThe European Atlantic sturgeon Acipenser sturio, formerly present throughout Europe, is currently represented by a very critically endangered population in the Gironde-Garonne-Dordogne basin in France. In spite of its protected status in France since 1982, the relict population has continued to decline. Better knowledge of its biology and ecology has been acquired with regard to potential spawning grounds, migrations both downstream into the estuary and on the continental shelf, strength of the last representative cohorts in the estuary, the inhabited area and feeding habits in the Gironde estuary, adaptation of stocked fish to the wild, and characteristics of wild brood fish (frequency, date, sex, reproductive status). Due to the dramatic decline in brood fish by-catch, only four artificial reproductions were successful between 1981 and 2006, the last taking place in 1995. This was the first opportunity to grow larvae and to mark fingerlings for stocking. From the early 1990s, brood-stock building appeared to be the only way to potentially produce fingerlings on a regular basis. As there were no references in either husbandry or related ecophysiology standards, a precautionary strategy was adopted. The most critical environmental factors are salinity, temperature, and light regime. Some encouraging results (semen with motile spermatozoa) were recorded from reconditioned adult males held in brackish water. Some females initiated only partial ovarian development and therefore we introduced some changes, especially in the temperature regime. Complementary investigation and data have been forthcoming through European cooperation on husbandry, feeding, genetics, and endocrinology and this will be developed. Further actions are briefly presented

Prerequisites for the restoration of the European Atlantic sturgeon, Acipenser sturio and the Baltic sturgeon (A. oxyrinchus x A. sturio) in Germany

International audienceAcipenser sturio was once a prevalent fish species in all the major rivers of Northern Germany. From the end of the nineteenth century, the population sizes have decreased rapidly. The last large population was observed in the River Eider, where the last specimen was caught in 1969. Under a cooperation agreement with the French Cemagref, the Leibniz-Institute of Freshwater Ecology and Inland Fisheries in Berlin received juvenile A. sturio of Gironde origin in 1996 and initiated an ex-situ measure. The main scientific results found since then have been: (1) first gonad maturation occurred in 11-year-old A. sturio (110 to 140 cm total length) kept in freshwater at 20°C under a natural photoperiod; (2) during vitellogenesis the growth factor insulin-growth-like factor (IGF-I) plays an important role as a paracrine modulator, as observed in the model species A. ruthenus; (3) analysis of recent and historical material revealed the presence of the A. oxyrinchus mitochondrial haplotype A in the Baltic. Investigation of the MHC (Major Histocompatibility Complex) nucleargene, however, showed that these fish carrying this haplotype represent a hybrid population (A. oxyrinchus × A. sturio). The current restoration strategy concerning the Baltic (restocking with A. oxyrinchus) therefore needs to be reconsidered. The mtDNA studies in addition demonstrated the genetic similarity of the Gironde and the North Sea population; (4) A. sturio-specific microsatellites were established for brood stock management of the German and French brood stocks; (5) Evaluation of historical spawning grounds in the River Oder drainage in collaboration with Polish scientists showed intact spawning grounds in the Drawa River