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Galactic stars belonging to the Of?p category are all strongly magnetic objects exhibiting rotationally modulated spectral and photometric changes on timescales of weeks to years. Five candidate Of?p stars in the Magellanic Clouds have been…

Solar and Stellar Astrophysics · Physics 2015-06-08 Yael Naze , Nolan R. Walborn , Nidia Morrell , Gregg A. Wade , Michal K. Szymanski

The paper deals with dynamics of expanding Lorenz maps, which appear in a natural way as Poincar\`e maps in geometric models of well-known Lorenz attractor. Using both analytical and symbolic approaches, we study connections between…

Dynamical Systems · Mathematics 2024-08-29 Łukasz Cholewa , Piotr Oprocha

In the context of adaptive optics for astronomy, one can rely on the statistics of the turbulent phase to assess a part of the system's performance. Temporal statistics with one source and spatial statistics with two sources are well-known…

Instrumentation and Methods for Astrophysics · Physics 2022-09-05 Cédric Plantet , Giulia Carlà , Guido Agapito , Lorenzo Busoni

Planet-scale photo geolocalization is the complex task of estimating the location depicted in an image solely based on its visual content. Due to the success of convolutional neural networks (CNNs), current approaches achieve super-human…

Computer Vision and Pattern Recognition · Computer Science 2021-10-22 Jonas Theiner , Eric Mueller-Budack , Ralph Ewerth

Pupil mapping is a promising and unconventional new method for high contrast imaging being considered for terrestrial exoplanet searches. It employs two (or more) specially designed aspheric mirrors to create a high-contrast amplitude…

Astrophysics · Physics 2007-05-23 Ruslan Belikov , N. Jeremy Kasdin , Robert J. Vanderbei

Machine learning is often viewed as a black box when it comes to understanding its output, be it a decision or a score. Automatic anomaly detection is no exception to this rule, and quite often the astronomer is left to independently…

Time domain astronomy has emerged as a vibrant research field in recent years, focusing on celestial objects that exhibit variable magnitudes or positions. Given the urgency of conducting follow-up observations for such objects, the…

Instrumentation and Methods for Astrophysics · Physics 2023-10-12 Rui Sun , Peng Jia , Yongyang Sun , Zhimin Yang , Qiang Liu , Hongyan Wei

For the observational modeling of horizontal abundance distributions and of magnetic geometries in chemically peculiar (CP) stars, Zeeman Doppler mapping (ZDM) has become the method of choice. Comparisons between abundance maps obtained for…

Solar and Stellar Astrophysics · Physics 2021-04-13 M. J. Stift , F. Leone

In theories where spacetime is a direct product of Minkowski space ($M^4$) and a d dimensional compact space ($K^d$), there can exist topological solitons that simultaneously wind around $R^3$ (or $R^2$ or $R^1$) in $M^4$ and the compact…

High Energy Physics - Theory · Physics 2011-02-09 C. S. Aulakh

This review summarizes popular unsupervised learning methods, and gives an overview of their past, current, and future uses in astronomy. Unsupervised learning aims to organise the information content of a dataset, in such a way that…

Instrumentation and Methods for Astrophysics · Physics 2024-06-26 Sotiria Fotopoulou

Among the group of extrasolar planets, transiting planets provide a great opportunity to obtain direct measurements for the basic physical properties, such as mass and radius of these objects. These planets are therefore highly important in…

Instrumentation and Methods for Astrophysics · Physics 2009-06-19 András Pál

The purpose of the present work is based on two main observations: the tensions encountered by the standard $\Lambda$CDM model when confronted to precision small scale cosmological data and the finding that the matter distribution and the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-20 Marie-Noëlle Célérier

We introduce a new method of searching for and characterizing extra-solar planets. We show that by monitoring the center-of-light motion of microlensing alerts using the next generation of high precision astrometric instruments the…

Astrophysics · Physics 2009-10-31 Neda Safizadeh , Neal Dalal , Kim Griest

The ideal imaging system would efficiently capture information about all fundamental properties light: intensity, direction, wavelength, and polarization. Most common imaging systems only map the spatial degrees of freedom of light onto a…

Optics · Physics 2023-01-26 Conner Ballew , Gregory Roberts , Andrei Faraon

In the context of current and future microwave surveys mainly dedicated to the accurate mapping of Cosmic Microwave Background (CMB), mm and sub-mm emissions from Solar System will represent a potential source of contamination as well as an…

Earth and Planetary Astrophysics · Physics 2015-05-13 Michele Maris , Carlo Burigana

Weak gravitational lensing is a widely used probe in cosmological analysis. It allows astrophysists to understand the content and evolution of the Universe. We are entering an era where we are not limited by the data volume but by…

Instrumentation and Methods for Astrophysics · Physics 2026-03-20 Axel Guinot , Rachel Mandelbaum

One-dimensional, semi-empirical models of the solar atmosphere are widely employed in numerous contexts within solar physics, ranging from the determination of element abundances and atomic parameters to studies of the solar irradiance and…

Solar and Stellar Astrophysics · Physics 2024-04-11 J. M. Borrero , I. Milic , A. Pastor Yabar , A. J. Kaithakkal , J. de la Cruz Rodriguez

We present a brief history of the construction of models of the universe, followed by calculations of quantitative characteristics of basic geometric and kinematic properties of the Standard Cosmological Model ($\Lambda$CDM). Using the…

General Relativity and Quantum Cosmology · Physics 2026-04-23 D. I. Nagirner , S. G. Jorstad , A. V. Dementyev

Interferometric observations of the Sun with ALMA provide valuable diagnostic tools for studying the small-scale dynamics of the solar atmosphere. Estimations of the observability of the small-scale dynamics as a function of spatial…

Solar and Stellar Astrophysics · Physics 2021-12-08 Henrik Eklund , Sven Wedemeyer , Mikołaj Szydlarski , Shahin Jafarzadeh

The characteristic formalism of numerical relativity is based on a system of coordinates aligned with outgoing null cones. While these coordinates were designed for studying gravitational waves, they can also be easily adapted to model…

General Relativity and Quantum Cosmology · Physics 2015-06-03 P. J. van der Walt , N. T. Bishop