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Concept

Étoile variable semi-régulière

Publications associées (24)

To grow old and peculiar: Survey of anomalous variable stars in M80 with age determinations using K2 and Gaia

Henryka Ewa Netzel

The globular cluster Messier 80 was monitored by the Kepler space telescope for 80 days during the K2 mission. Continuous, high-precision photometry of such an old, compact cluster allows us for studies of its variable star population in unprecedented deta ...

Edp Sciences S A2023

The Pristine survey - XXI. Exploring the metal-poor boundary with ESPaDoNS

Pascale Jablonka

In this paper, we study high-resolution spectra of 19 stars that have metallicity estimates below -3.5 using at least two metallicity-sensitive photometric indices based on Pristine photometry. The purpose is to understand what kind of stars populate this ...

OXFORD UNIV PRESS2023

J1721+8842: a gravitationally lensed binary quasar with a proximate damped Lyman-alpha absorber

Frédéric Courbin, Martin Raoul Robert Millon, Hung-Hsu Chan, Eric Gérard Guy Paic, Cameron Alexander Campbell Lemon

High-redshift binary quasars provide key insights into mergers and quasar activity, and are useful tools for probing the spatial kinematics and chemistry of galaxies along the line of sight. However, only three sub-10-kpc binaries have been confirmed above ...

EDP SCIENCES S A2022

Discovery of Slow Variables in a Class Of Multiscale Stochastic Systems Via Neural Networks

Jan Sickmann Hesthaven, Przemyslaw Zielinski

Finding a reduction of complex, high-dimensional dynamics to its essential, low-dimensional "heart" remains a challenging yet necessary prerequisite for designing efficient numerical approaches. Machine learning methods have the potential to provide a gene ...

2022

Lithium in red giant stars: Constraining non-standard mixing with large surveys in the Gaia era

Pierre North

Context. Li is extensively known to be a good tracer of non-standard mixing processes occurring in stellar interiors. Aims. We present the results of a new large Li survey in red giant stars and combine it with surveys from the literature to probe the impa ...

EDP SCIENCES S A2020

Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram

Stephan Morgenthaler, Shuangqing Liao

Context. The ESA Gaia mission provides a unique time-domain survey for more than 1.6 billion sources with G less than or similar to 21 mag. ...

EDP SCIENCES S A2019

Gaia Data Release 2 Summary of the variability processing and analysis results

Stephan Morgenthaler, Mária Süveges, Lorenzo Diana

Context. The Gaia Data Release 2 (DR2) contains more than half a million sources that are identified as variable stars. ...

EDP SCIENCES S A2018

An Origami-Inspired Reconfigurable Suction Gripper for Picking Objects with Variable Shape and Size

Aude Billard, Jamie Paik, Zhenishbek Zhakypov

Gripper adaptability to handle objects of different shape and size brings high flexibility to manipulation. Gripping flat, round, or narrow objects poses challenges to even the most sophisticated robotic grippers. Among various gripper technologies, the va ...

2018

Probabilistic S-N curves for constant and variable amplitude

Alain Nussbaumer, Cláudio Alexandre Pereira Baptista

Welded details in steel bridges are subjected to fatigue lives up to 200.10(6) cycles due to traffic loads. While the majority of these stress ranges are below the Constant Amplitude Fatigue Limit (CAFL), some few high stress cycles can trigger the start o ...

Elsevier Sci Ltd2017

Testing parallaxes with local Cepheids and RR Lyrae stars

Stephan Morgenthaler, Shuangqing Liao

Context. Parallaxes for 331 classical Cepheids, 31 Type II Cepheids, and 364 RR Lyrae stars in common between Gaia and the HIPPARCOS and Tycho-2 catalogues are published in Gaia Data Release 1 (DR1) as part of the Tycho-Gaia Astrometric Solution (TGAS). Ai ...

Edp Sciences S A2017

Dependent Object Types

Nada Amin

A scalable programming language is one in which the same concepts can describe small as well as large parts. Towards this goal, Scala unifies concepts from object and module systems. In particular, objects can contain type members, which can be selected as ...

EPFL2016

Gaia Data Release 1 Summary of the astrometric, photometric, and survey properties

Stephan Morgenthaler, Shuangqing Liao

Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. Aims. A summary of Gaia DR1 is presented along with illu ...

EDP Sciences2016

Multiaxial and variable amplitude fatigue in steel bridges

Cláudio Alexandre Pereira Baptista

Modern bridge construction all over Europe in the last decades, has highlighted the importance of steel solutions for the design of bridges. Steel bridges have become slender and lighter with the generalisation of welded connections. These features increas ...

EPFL2016

Calibration of partial safety factors for fatigue design of steel bridges

Alain Nussbaumer, Luca D'Angelo

The aim of this paper is to propose a new framework for assessment of fatigue partial safety factors with focus on steel bridges welded joints. Fatigue resistance S-N curves for constant amplitude (CA) and variable amplitude (VA) loadings are defined using ...

2015

Effects of realistic office daylighting and electric lighting conditions on visual comfort, alertness and mood

Jean-Louis Scartezzini, Friedrich Linhart, Apiparn Borisuit

Lighting conditions in workplaces contribute to a variety of factors related to work satisfaction, productivity and well-being. We tested whether different photometric variables also influence visual perception and the comfort of the lighting, as well as s ...

Sage Publications Ltd2015

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses XI. Techniques for time delay measurement in presence of microlensing

Frédéric Courbin, Georges Meylan, Malte Tewes

Measuring time delays between the multiple images of gravitationally lensed quasars is now recognized as a competitive way to constrain the cosmological parameters, and it is complementary with other cosmological probes. This requires long and well sampled ...

Edp Sciences S A2013

La détection de périodicités cachées

Jean-Marc Nicoletti

This thesis is a small part of the preparation of the launch of the Gaia mission, a satellite of the European Space Agency (ESA). One of the goals of the mission is to perform a classification among variable stars considering different attributes. Periodic ...

EPFL2012

A statistical method for draft tube pressure pulsation analysis

Nicolas Ruchonnet

Draft tube pressure pulsation (DTPP) in Francis turbines is composed of various components originating from different physical phenomena. These components may be separated because they differ by their spatial relationships and by their propagation mechanis ...

International Association For Hydraulic Research2012

Reduction strategies for PDE-constrained optimization problems in haemodynamics

Gianluigi Rozza, Andrea Manzoni, Federico Negri

Solving optimal control problems for many different scenarios obtained by varying a set of parameters in the state system is a computationally extensive task. In this paper we present a new reduced framework for the formulation, the analysis and the numeri ...

Vienna Technical University2012

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Frédéric Courbin, Georges Meylan, Yves Revaz, Malte Tewes

We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar ...

2011