Caracterização estelar e exoplanetária a partir de espectros APOGEE

Este trabalho tem como objetivos principais realizar uma revisão bibliográfica do campo de estudo de exoplanetas e analisar a habitabilidade planetária para uma amostra de exoplanetas que orbitam estrelas FGK e anãs M, fazendo uso dos dados do survey APOGEE (Apache Point Observatory Galactic Evolution Experiment). A revisão bibliográfica aborda os principais temas relativos ao estudo de exoplanetas, tais como métodos de detecção, parâmetros estelares e exoplanetários, além da apresentação da base de exoplanetas da NASA (Nasa Exoplanet Archive), e do survey APOGEE. A análise de habitabilidade foi realizada para uma amostra de 29 exoplanetas de estrelas anãs M (referentes a 19 estrelas) e 261 exoplanetas de estrelas FGK (referentes a 141 estrelas), totalizando 290 exoplanetas (referentes a 160 estrelas). Este trabalho apresenta um foco especial em exoplanetas que orbitam anãs M. As análises de habitabilidade utilizaram dados estelares e exoplanetários obtidos de diversas fontes, entre elas: base de Exoplanetas da NASA, ASPCAP (APOGEE Stellar Parameters and Chemical Abundances Pipeline), calibrações fotométricas e síntese espectral. Neste trabalho, foi realizada síntese espectral em 1-D ETL (equilíbrio termodinâmico local) e geometria plana-paralela por meio do programa Turbospectrum, fazendo uso de interpolação de modelos de atmosferas MARCS. Determinamos parâmetros atmosféricos (Tef e log g) e abundâncias químicas para 5 elementos (C, O, Mg, Si e Fe). Determinamos parâmetros exoplanetários tais como temperatura de equilíbrio e grau de insolação. Um total de 17 exoplanetas da amostra se encontram dentro da zona habitável de suas respectivas estrelas, dos quais 6 orbitam estrelas anãs M (GJ 273 b, GJ 625 b, GJ 687 b, Kepler-1410 b, Kepler-186 f e Ross 128 b). Adicionalmente, segundo os critérios adotados na análise de razões de abundâncias C/O e Mg/Si, um total de 57 estrelas possuem uma maior possibilidade de abrigar exoplanetas rochosos com estrutura interna similar a Terra. Dessas, 5 são anãs M e abrigam 6 exoplanetas (GJ 273 b, GJ 273 c, GJ 625 b, GJ 687 b, Kepler-1651 b e Ross 128 b). Por fim, foi realizada uma análise de relações massa-raio, com o objetivo de determinar exoplanetas com maiores probabilidades de serem rochosos. Nenhum dos exoplanetas que atenderam aos critérios anteriores de habitabilidade foram elegíveis para essa análise, que trouxe 5 exoplanetas de estrelas FGK e um de estrelas anãs M (Kepler-138 c) da amostra classificados como tendo maiores probabilidades de serem rochosos

The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data

This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora