US Department of Energy; US National Science Foundation; Ministry of Science and Education of Spain; Science and Technology Facilities Council of the United Kingdom; Higher Education Funding Council for England; National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign; Kavli Institute of Cosmological Physics at the University of Chicago; Center for Cosmology and Astro-Particle Physics at the Ohio State University; Mitchell Institute for Fundamental Physics and Astronomy at Texas AM University; Financiadora de Estudos e Projetos; Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico and the Ministerio da Ciencia; Tecnologia e Inovacao; Deutsche Forschungsgemeinschaft; Collaborating Institutions in the Dark Energy Survey; National Science Foundation [AST-1138766]; University of California at Santa Cruz; University of Cambridge, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas-Madrid; University of Chicago, University College London; DES-Brazil Consortium; University of Edinburgh; Eidgenossische Technische Hochschule (ETH) Zurich, Fermi National Accelerator Laboratory; University of Illinois at Urbana-Champaign; Institut de Ciencies de l'Espai (IEEC/CSIC); Institut de Fisica d'Altes Energies, Lawrence Berkeley National Laboratory; Ludwig-Maximilians Universitat Munchen; European Research Council [FP7/291329]; MINECO [AYA2012-39559, ESP2013-48274, FPA2013-47986]; Centro de Excelencia Severo Ochoa [SEV-2012-0234]; European Research Council under the European Union [240672, 291329, 306478]
Large language models (LLMs) have recently demonstrated exceptional capabilities across a variety of linguistic tasks including question answering (QA). However, it remains challenging to assess their performance in astronomical QA due to the lack of comprehensive benchmark datasets. To bridge this gap, we construct Astro-QA, the first benchmark dataset specifically for QA in astronomy. The dataset contains a collection of 3,082 questions of six types in both English and Chinese, along with standard (reference) answers and related material. These questions encompass several core branches of astronomy, including astrophysics, astrometry, celestial mechanics, history of astronomy, and astronomical techniques and methods. Furthermore, we propose a new measure called DGscore that integrates different measures for objective and subjective questions and incorporates a weighting scheme based on type- and question-specific difficulty coefficients to accurately assess the QA performance of each LLM. We validate the Astro-QA dataset through extensive experimentation with 27 open-source and commercial LLMs. The results show that it can serve as a reliable benchmark dataset to evaluate the capacity of LLM in terms of instruction following, knowledge reasoning, and natural language generation in the astronomical domain, which can calibrate current progress and facilitate future research of astronomical LLMs.
Dark matter could be composed of macroscopic objects with large masses and geometric cross-sections spanning many decades. We investigate the potential interaction of such `stuff-sized' dark matter by considering its interactions with asteroids, planetary rings, and terrestrial bodies. This hail of dark matter could catastrophically destroy these Solar System objects, evaporate them from their orbits, or cause substantial cratering. We estimate these effects and use them to place competitive bounds on a wide, previously-unconstrained swathe of the dark matter parameter space.
Jerry Jun-Yan Zhang, Nicolas Lodieu, Eduardo L. Martín
We present deep $K_s$-band imaging of the extreme T subdwarf CWISE J221706.28$-$145437.6. Using the new photometry, we construct its spectral energy distribution and find this object exhibits exceptionally strong collision-induced absorption in the $H$ and $K$ bands. The comparison with the nearest benchmark extreme T subdwarf WISEA J181006.18$-$101000.5 suggests the object would be cooler and more metal-poor than the benchmark.
In this white paper, we propose an upgrade to the Very Large Telescope Interferometer (VLTI) consisting of the addition of a new 8m Unit Telescope (UT5). The primary goal of this upgrade is to optimise the VLTI for exoplanet detection by creating four additional baselines of approximately 200m oriented toward the north-west. The inclusion of this telescope would reduce the inner working angle and improve the achievable contrast of the VLTI, thereby enabling the detection of mature exoplanets in reflected light.
Lee D. Feinberg, John Ziemer, Megan Ansdell
et al.
NASA began the Great Observatory Maturation Program (GOMAP) with the goal of studying and advancing the Habitable Worlds Observatory (HWO), a large ultraviolet, optical, infrared space telescope recommended by the Astro 2020 Decadal Survey. Among its many goals, HWO will obtain spectra of at least 25 exo-Earth candidates to search for signs of life and conduct transformative astrophysics at ultraviolet, optical, and near-infrared wavelengths. The observatory, like HST and JWST, will be a powerful general class observatory. This past fall the GOMAP program stood up two study groups, the Science Technology Architecture Review Team (START) and the Technical Assessment Group (TAG) aimed at helping to study the science, technology and architecture options for this new flagship mission. This talk will discuss the engineering activities associated with these studies including the team and organization, the study plan and the use of the Concept Maturity Level (CML) approach. In addition, the talk will discuss the key initial engineering efforts, the key technology gaps, and overall engineering plans.
Principal Component Analysis (PCA)-based techniques can separate data into different uncorrelated components and facilitate the statistical analysis as a pre-processing step. Independent Component Analysis (ICA) can separate statistically independent signal sources through a non-parametric and iterative algorithm. Non-negative matrix factorization is another PCA-similar approach to categorizing dimensions in physically-interpretable groups. Singular spectrum analysis (SSA) is a time-series-related PCA-like algorithm. After an introduction and a literature review on processing JWST data from the Near-Infrared Camera (NIRCam) and Mid-Infrared Instrument (MIRI), potential parts to intervene in the James Webb Space Telescope imaging data reduction pipeline will be discussed.
Frymire & Ardila (2023) reported an anomalous flux variation in the Transiting Exoplanet Survey Satellite (TESS) Sector 43 light curve of the white dwarf HZ 4. We show that this flux variation was caused by the main-belt asteroid 4382 Stravinsky traversing the nearby TESS pixels, and it is therefore not a cause for concern regarding the continued use of HZ 4 as a photometric standard star.
Buracos negros são objetos astrofísicos com propriedades muito particulares e fascinante. A partir de hipóteses genéricas, como a validade da teoria da relatividade geral, é possível provar teoremas que garantem a existência e propriedades desses objetos. Porém, apenas a observação e os experimentos são capazes de testar e verificar afirmações sobre fenômenos naturais. Seguindo este raciocínio, iremos desenvolver os conceitos básicos do que é um buraco negro, explicitar algumas de suas propriedades peculiares e por fim pontuar as observações que comprovaram a existência desses objetos compactos.
Buracos negros existem em todo lado no nosso universo. Segundo a relatividade geral, estes objetos são clássicos e não emitem qualquer radiação, são negros. No entanto, quando se considera campos quânticos, verifica-se que os buracos negros são na realidade objetos termodinâmicos e que não são assim tão negros. Neste artigo, fazemos a exposição de como um buraco negro é termodinâmico. Primeiro, fazemos uma exposição breve da descrição clássica dos buracos negros e as suas quatro leis de mecânica. Depois, fazemos a exposição dos primeiros trabalhos que avançaram a ideia de que os buracos negros são termodinâmicos. Finalmente, fazemos a exposição do formalismo que permite tratar a termodinâmica de espaços-tempos contendo buracos negros e referimos muito brevemente a sua investigação recente.
The aim of this study is to construct a simple stellar model with non-uniform polytropic index. We find that the Emden equation cannot deal with the polytrope gas sphere with non-uniform polytropic index in a real star, and then we construct a realistic stellar model. The key point is that we should solve the two independent equations for density and pressure due to the essence of polytropic relation, but not the Emden equation which combines the hydrostatic balance and polytropic relation. We take the Sun for a computational example to find that this simple model yields quite a good result compared to the MESA code. The advantage of this simple model lies in its much simpler equation of state than that in the standard stellar model.
Frequencies of volcanic eruptions in the past 270 years are compared with variations of solar activity and summary curve of principal components of the solar background magnetic field (SBMF).Frequency analysis with Morlet wavelet reveals the most pronounced period of volcanic eruptions of 22 years. There is a strong correlation (0.84) between volcanic frequencies and the summary curve of SBMF for 11 cycles after 1868. The maxima of volcanic eruptions are shown to occur during solar activity cycles with the southern magnetic polarity. The next anticipated maximum of volcanic eruptions is expected to occur during cycle 26, when SBMF have a southern magnetic polarity.
In this contribution, I briefly review the long-term evolution of the solar wind (its mass-loss rate), including the evolution of observed properties that are intimately linked to the solar wind (rotation, magnetism and activity). I also briefly discuss implications of the evolution of the solar wind on the evolving Earth. I argue that studying exoplanetary systems could open up new avenues for progress to be made in our understanding of the evolution of the solar wind.
In the spirit of Trimble's "Astrophysics in XXXX' series, I very briefly and subjectively review developments in SETI in 2020. My primary focus is 75 papers and books published or made public in 2020, which I sort into six broad categories: results from actual searches, new search methods and instrumentation, target and frequency seleciton, the development of technosignatures, theory of ETIs, and social aspects of SETI.
O Museu da Amazônia, o Musa, é um museu vivo, a céu aberto na Reserva Ducke, uma floresta primária na cidade de Manaus. Os ecossistemas, a fauna e a flora desta floresta, têm sido estudados há mais de cinquenta anos pelos pesquisadores do INPA. O Musa está empenhado em divulgar para o grande público os segredos desta floresta. Mostrar ao vivo, em seu habitat natural, as plantas, os pássaros, insetos, flores e polinizadores. É propósito do Musa em suas exposições valorizar os saberes das culturas indígenas que habitaram e ainda habitam as florestas amazônicas. No Musa são também cultivadas e divulgadas práticas agrícolas compatíveis com a presença da floresta, explorando assim modos antigos de compreender o mundo que propiciam o ‘viver juntos’ de culturas e saberes de humanos e não humanos.
As detecções de ondas gravitacionais geradas de sistemas binários coalescentes deixaram um marco na física, começando a nova ciência da astronomia de ondas gravitacionais e abrindo novas linhas de pesquisa em física fundamental e cosmologia. Aqui expomos as consequências dessa nova forma de enxergar, ou ouvir, objetos astrofísicos para a compreensão das leis fundamentais da gravitação e da história do Universo.
An ionization plays a key role in formation of stars, planets and their atmospheres. Cosmic rays (CR) are the main source of the ionization, therefore it is important to know and be able to estimate fluxes of galactic and stellar cosmic rays (GCR and SCR) at different stages of evolution of stars and planetary systems. Radiation conditions close to exoplanets might be important for creation and development of life. We present a review of the current state of the problem of astrospheres and their interactions with GCR and SCR. We pay special attention to estimates of radiation conditions near exoplanets recently discovered in a habitable zone of their hosting stars.