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Astrophysical uncertainties in dark matter direct detection experiments are typically addressed by parametrizing the velocity distribution in terms of a few uncertain parameters that vary around some central values. Here we propose a method…

High Energy Physics - Phenomenology · Physics 2025-01-20 Gonzalo Herrera , Andreas Rappelt

This paper presents a comparison of popular period finding algorithms applied to the light curves of variable stars from the Catalina Real-time Transient Survey (CRTS), MACHO and ASAS data sets. We analyze the accuracy of the methods…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 Matthew J. Graham , Andrew J. Drake , S. G. Djorgovski , Ashish A. Mahabal , Ciro Donalek , Victor Duan , Alison Maher

Microvariability consists in small time scale variations of low amplitude in the photometric light curves of quasars, and represents an important tool to investigate their inner core. Detection of quasar microvariations is challenging for…

Instrumentation and Methods for Astrophysics · Physics 2016-08-08 J. A. de Diego , J. Polednikova , A. Bongiovanni , A. M. Pérez García , M. A. De Leo , T. Verdugo , J. Cepa

A common problem in astronomy is the determination of the time shift between two otherwise identical time series of measured flux from a variable source, in short the determination of a time lag. Two examples of where this problem occurs…

Astrophysics · Physics 2007-05-23 Frank P. Pijpers

We make an experimental comparison of methods for computing the numerical radius of an $n\times n$ complex matrix, based on two well-known characterizations, the first a nonconvex optimization problem in one real variable and the second a…

Numerical Analysis · Mathematics 2023-10-10 Tim Mitchell , Michael L. Overton

Ongoing and future surveys with repeat imaging in multiple bands are producing (or will produce) time-spaced measurements of brightness, resulting in the identification of large numbers of variable sources in the sky. A large fraction of…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 Abhijit Saha , A. Katherina Vivas

Modern astronomical surveys produce millions of light curves of variable sources. These massive data sets challenge the community to create automatic light-curve processing methods for detection, classification, and characterisation of…

Instrumentation and Methods for Astrophysics · Physics 2023-09-20 Anastasia Lavrukhina , Konstantin Malanchev , Matwey V. Kornilov

Automatic classification methods applied to sky surveys have revolutionized the astronomical target selection process. Most surveys generate a vast amount of time series, or \quotes{lightcurves}, that represent the brightness variability of…

Instrumentation and Methods for Astrophysics · Physics 2018-01-31 Nicolas Castro , Pavlos Protopapas , Karim Pichara

We derive analytic, closed-form solutions for the light curve of a planet transiting a star with a limb darkening profile which is a polynomial function of the stellar elevation, up to arbitrary integer order. We provide improved analytic…

Earth and Planetary Astrophysics · Physics 2020-03-04 Eric Agol , Rodrigo Luger , Daniel Foreman-Mackey

We have developed a timing analysis method to determine the distances of variable galactic X-ray sources based on the method advanced by Tr\"{u}mper and Sch\"{o}nfelder in 1973. The light-curve of the halo produced by the scattering of…

Astrophysics · Physics 2016-01-27 J. Hu , S. N. Zhang , T. P. Li

An algorithm is presented which generates pairs of oscillatory random time series which have identical periodograms but differ in the number of oscillations. This result indicate the intrinsic limitations of spectral methods when it comes…

Data Analysis, Statistics and Probability · Physics 2007-05-23 A. G. Rossberg

We consider from a general point of view the problem of determining the extinction in dense molecular clouds. We use a rigorous statistical approach to characterize the properties of the most widely used optical and infrared techniques,…

Astrophysics · Physics 2009-11-11 Marco Lombardi

A formula is given for the propagation of errors during matrix inversion. An explicit calculation for a 2 by 2 matrix using both the formula and a Monte Carlo calculation are compared. A prescription is given to determine when a matrix with…

High Energy Physics - Experiment · Physics 2009-10-31 M. Lefebvre , R. K. Keeler , R. Sobie , J. White

Using a sample of 454 mira light curves from the ASAS survey we study the shape of the light variations in this kind of variable stars. Opposite to earlier studies, we choose a general approach to identify any deviation from a sinusoidal…

Solar and Stellar Astrophysics · Physics 2015-05-20 T. Lebzelter

In this work, we present a framework for estimating and evaluating uncertainty in deep-attention-based classifiers for light curves for variable stars. We implemented three techniques, Deep Ensembles (DEs), Monte Carlo Dropout (MCD) and…

Instrumentation and Methods for Astrophysics · Physics 2024-11-05 Martina Cádiz-Leyton , Guillermo Cabrera-Vives , Pavlos Protopapas , Daniel Moreno-Cartagena , Cristobal Donoso-Oliva

For a group of the Mira-type stars, semi-regular variables and some RV Tau - type stars the limit cycles were computed and plotted using the phase plane diagrams. As generalized coordinates x and $\dot{x},$ we have used $\phi$ - the…

Solar and Stellar Astrophysics · Physics 2017-11-27 L. S. Kudashkina , I. L. Andronov

We present a fast algorithm to produce light curves of distant stars undergoing microlensing near critical curves. The need of these type of algorithms is motivated by recent observations of microlensing events of distant stars at high…

Instrumentation and Methods for Astrophysics · Physics 2022-10-05 J. M. Diego

This paper proposes k-medoids clustering method to reveal the distinct groups of 1,318 variable stars in the Galaxy based on their light curves, where each light curve represents the graph of brightness of the star against time. To overcome…

Solar and Stellar Astrophysics · Physics 2020-06-25 Soumita Modak , Tanuka Chattopadhyay , Asis Kumar Chattopadhyay

Astronomical data are typically irregular in time, e.g. the space (HIPPARCOS/TYCHO, KEPLER, GAIA, WISE etc.) and ground-based CCD (NSVS, ASAS, CRTS, SuperWASP etc.) and photographic (Harvard, Sonneberg, Odessa etc.) photometrical surveys.…

Solar and Stellar Astrophysics · Physics 2019-02-05 Ivan L. Andronov

Recent studies indicate that the physical properties of eclipsing binaries can be extracted from the derivatives of their light curves. A classification scheme for the derivatives of light curves would be helpful for identifying key…

Solar and Stellar Astrophysics · Physics 2025-05-28 Shinjirou Kouzuma