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The use of 3D hydrodynamical simulations of stellar surface convection for model atmospheres is computationally expensive. Although these models have been available for quite some time, their use is limited because of the lack of extensive…

Solar and Stellar Astrophysics · Physics 2022-05-25 S. Bertran de Lis , C. Allende Prieto , H. -G. Ludwig , L. Koesterke

We present tests carried out on optical and infrared stellar spectra to evaluate the accuracy of different types of interpolation. Both model atmospheres and continuum normalized fluxes were interpolated. In the first case we used linear…

Solar and Stellar Astrophysics · Physics 2015-06-12 Sz. Mészáros , C. Allende Prieto

NEMO.2003 (vienna NEw MOdel grid of stellar atmospheres) is a DVD with 91,520 stellar model atmospheres representing a 5D grid of modified ATLAS9 atmospheres; the purpose of the modifications was to include different treatments of…

Astrophysics · Physics 2007-05-23 J. Nendwich , U. Heiter , F. Kupka , N. Nesvacil , W. W. Weiss

A method based on Generative Adversaria! Networks (GANs) is developed for disentangling the physical (effective temperature and gravity) and chemical (metallicity, overabundance of a-elements with respect to iron) atmospheric properties in…

Instrumentation and Methods for Astrophysics · Physics 2025-02-26 Minia Manteiga , Raúl Santoveña , Marco A. Álvarez , Carlos Dafonte , Manuel G. Penedo , Silvana Navarro , Luis Corral

Theoretical stellar spectra rely on model stellar atmospheres computed based on our understanding of the physical laws at play in the stellar interiors. These models, coupled with atomic and molecular line databases, are used to generate…

Solar and Stellar Astrophysics · Physics 2020-07-01 Kaushal Sharma , Harinder P. Singh , Ranjan Gupta , Ajit Kembhavi , Kaustubh Vaghmare , Jianrong Shi , Yongheng Zhao , Jiannan Zhang , Yue Wu

1D stellar evolution codes employ rudimentary treatments of turbulent convection. For stars with convective envelopes, this leads to systematic errors in the predicted oscillation frequencies needed for asteroseismology. One way of mending…

Solar and Stellar Astrophysics · Physics 2019-02-13 Andreas Christ Sølvsten Jørgensen , Achim Weiss , George Angelou , Víctor Silva Aguirre

We present a nonlinear interpolation technique for parametric fields that exploits optimal transportation of coherent structures of the solution to achieve accurate performance. The approach generalizes the nonlinear interpolation procedure…

Numerical Analysis · Mathematics 2023-10-09 Simona Cucchiara , Angelo Iollo , Tommaso Taddei , Haysam Telib

The absorption of light by molecules in the atmosphere of Earth is a complication for ground-based observations of astrophysical objects. Comprehensive information on various molecular species is required to correct for this so called…

Instrumentation and Methods for Astrophysics · Physics 2021-11-18 Rune D. Kjærsgaard , Aaron Bello-Arufe , Alexander D. Rathcke , Lars A. Buchhave , Line K. H. Clemmensen

Standard 1D stellar evolution models do not correctly reproduce the structure of the outermost layers of stars with convective envelopes. This has been a long-standing problem in stellar modelling affecting both the predicted evolutionary…

The fast and accurate estimation of planetary mass-loss rates is critical for planet population and evolution modelling. We use machine learning (ML) for fast interpolation across an existing large grid of hydrodynamic upper atmosphere…

Earth and Planetary Astrophysics · Physics 2025-02-04 Amit Reza , Daria Kubyshkina , Luca Fossati , Christiane Helling

Machine learning has been widely applied to clearly defined problems of astronomy and astrophysics. However, deep learning and its conceptual differences to classical machine learning have been largely overlooked in these fields. The broad…

Instrumentation and Methods for Astrophysics · Physics 2024-10-15 Nima Sedaghat , Martino Romaniello , Jonathan E. Carrick , François-Xavier Pineau

This article investigates the problem of estimating stellar atmospheric parameters from spectra. Feature extraction is a key procedure in estimating stellar parameters automatically. We propose a scheme for spectral feature extraction and…

Instrumentation and Methods for Astrophysics · Physics 2015-08-04 Tan Yang , Xiangru Li

We present a learning-based method for interpolating and manipulating 3D shapes represented as point clouds, that is explicitly designed to preserve intrinsic shape properties. Our approach is based on constructing a dual encoding space…

Computer Vision and Pattern Recognition · Computer Science 2021-05-07 Marie-Julie Rakotosaona , Maks Ovsjanikov

Present grids of stellar atmosphere models are the workhorses in interpreting stellar observations, and determining their fundamental parameters. These models rely on greatly simplified models of convection, however, lending less predictive…

Solar and Stellar Astrophysics · Physics 2015-06-15 Regner Trampedach , Martin Asplund , Remo Collet , Åke Nordlund , Robert F. Stein

Exploring exoplanets has transformed our understanding of the universe by revealing many planetary systems that defy our current understanding. To study their atmospheres, spectroscopic observations are used to infer essential atmospheric…

Earth and Planetary Astrophysics · Physics 2025-12-19 Flavio Giobergia , Alkis Koudounas , Elena Baralis

$Aims.$ We present a database of 43,340 atmospheric models ($\sim$80,000 models at the conclusion of the project) for stars with stellar masses between 9 and 120 $M_{\odot}$, covering the region of the OB main-sequence and Wolf-Rayet (W-R)…

Solar and Stellar Astrophysics · Physics 2020-11-18 J. Zsargo , C. R. Fierro-Santillan , J. Klapp , A. Arrieta , L. Arias , J. M. Valencia , L. Di G. Sigalotti , M. Hareter , R. E. Puebla

Due to the ever-expanding volume of observed spectroscopic data from surveys such as SDSS and LAMOST, it has become important to apply artificial intelligence (AI) techniques for analysing stellar spectra to solve spectral classification…

Solar and Stellar Astrophysics · Physics 2020-01-08 Kaushal Sharma , Ajit Kembhavi , Aniruddha Kembhavi , T. Sivarani , Sheelu Abraham , Kaustubh Vaghmare

This paper addresses the problem of generating dense point clouds from given sparse point clouds to model the underlying geometric structures of objects/scenes. To tackle this challenging issue, we propose a novel end-to-end learning-based…

Computer Vision and Pattern Recognition · Computer Science 2022-03-30 Yue Qian , Junhui Hou , Sam Kwong , Ying He

Atmospheric retrievals on exoplanets usually involve computationally intensive Bayesian sampling methods. Large parameter spaces and increasingly complex atmospheric models create a computational bottleneck forcing a trade-off between…

Instrumentation and Methods for Astrophysics · Physics 2018-11-28 Tiziano Zingales , Ingo Peter Waldmann

In this paper we design a neural interpolation operator to improve the boundary data for regional weather models, which is a challenging problem as we are required to map multi-scale dynamics between grid resolutions. In particular, we…

Machine Learning · Computer Science 2025-05-20 James Jackaman , Oliver Sutton
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