Publications associées à Céphéide

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

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

Detailed asteroseismic modelling of RR Lyrae stars with non-radial modes

Henryka Ewa Netzel

Photometric observations from the last decade have revealed additional low-amplitude periodicities in many classical pulsators that are likely due to pulsations in non-radial modes. One group of multimode RR Lyrae stars, the so-called 0.61 stars, is partic ...

Oxford Univ Press2023

Gaia Focused Product Release: Radial velocity time series of long-period variables

Stephan Morgenthaler, Shuangqing Liao

Context. The third Gaia Data Release (DR3) provided photometric time series of more than 2 million long-period variable (LPV) candidates. Anticipating the publication of full radial-velocity data planned with Data Release 4, this Focused Product Release (F ...

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

Gaia Data Release 3 Summary of the variability processing and analysis

Mária Süveges

Context. Gaia has been in operations since 2014, and two full data releases (DR) have been delivered so far: DR1 in 2016 and DR2 in 2018. The third Gaia data release expands from the early data release (EDR3) in 2020, which contained the five-parameter ast ...

EDP SCIENCES S A2023

The evolution of the Milky Way's thin disc radial metallicity gradient with K2 asteroseismic ages

Saniya Khan

The radial metallicity distribution of the Milky Way's disc is an important observational constraint for models of the formation and evolution of our Galaxy. It informs our understanding of the chemical enrichment of the Galactic disc and the dynamical pro ...

Oxford Univ Press2023

Crowded No More: The Accuracy of the Hubble Constant Tested with High-resolution Observations of Cepheids by JWST

Richard Irving Anderson

High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWS ...

Iop Publishing Ltd2023

How much metal did the first stars provide to the ultra-faint dwarfs?

Pascale Jablonka, Yves Revaz, Mahsa Sanati

Numerical simulations of dwarf galaxies have so far failed to reproduce the observed metallicity-luminosity relation, down to the regime of ultra-faint dwarfs (UFDs). We address this issue by exploring how the first generations of metal-free stars (Pop III ...

EDP SCIENCES S A2023

The eta Aquilae System: Radial Velocities and Astrometry in Search of eta Aql B

Richard Irving Anderson

The classical Cepheid eta Aql was not included in past Leavitt Law work because of a presumed complicating orbit due to a known B9.8V companion. To determine the orbit of eta Aql B, we analyze a significant number of radial velocity (RV) measurements from ...

2022

Discovery of a Binary-origin Classical Cepheid in a Binary System with a 59 day Orbital Period

Richard Irving Anderson

We report the discovery of a surprising binary configuration of the double-mode Cepheid OGLE-LMC-CEP-1347 pulsating in the first (P-1= 0.690 days) and second-overtone (P-2= 0.556 days) modes. The orbital period (P-orb= 59 days) of the system is five times ...

Iop Publishing Ltd2022

Synthesis of near-diffraction-free orbital-angular-momentum space-time wave packets having a controllable group velocity using a frequency comb

Tobias Kippenberg, Maxim Karpov, Zhe Zhao, Hao Song, Xinzhou Su

Novel forms of light beams carrying orbital angular momentum (OAM) have recently gained interest, especially due to some of their intriguing propagation features. Here, we experimentally demonstrate the generation of near-diffraction-free two-dimensional ( ...

Optica Publishing Group2022

Auto-tuning deep forest for shear stiffness prediction of headed stud connectors

Xianlin Wang, Yuqing Liu

The shear stiffness of headed stud connector is a critical parameter for the calculation of deflection and inter-facial shear force for steel-concrete composite structure. Thus, this study presented a promising data-driven model auto-tuning Deep Forest (AT ...

2022

Time-delay estimation in unresolved lensed quasars

Georgios Vernardos

Time-delay cosmography can be used to infer the Hubble parameter H-0 by measuring the relative time delays between multiple images of gravitationally lensed quasars. A few of such systems have already been used to measure H-0: Their time delays were determ ...

OXFORD UNIV PRESS2022

Covariant formulation of relativistic mechanics

Miguel Alexandre Ribeiro Correia

Accretion disks surrounding compact objects, and other environmental factors, deviate satellites from geodetic motion. Unfortunately, setting up the equations of motion for such relativistic trajectories is not as simple as in Newtonian mechanics. The prin ...

American Physical Society2022

Isogeometric Kirchhoff-Love shell patches in free and forced vibration of sinusoidally corrugated FG carbon nanotube-reinforced composite panels

Anastasios Vassilopoulos

Application of the isogeometric method is illustrated for free and forced vibration analyzes of sinusoidally corrugated functionally graded carbon nanotube reinforced composite (FG-CNTRC) thin panels. These panels can be used as a potential structure for m ...

ELSEVIER SCI LTD2022

Cepheids with Giant Companions. I. Revealing a Numerous Population of Double-lined Binary Cepheids* (dagger)

Richard Irving Anderson

Masses of classical Cepheids of 3-11 M are predicted by theory but those measured clump between 3.6-5 M. As a result, their mass-luminosity relation is poorly constrained, impeding our understanding of basic stellar physics and the Leavitt Law. All Cepheid ...

2021

Exploring the coupled ocean and atmosphere system with a data science approach applied to observations from the Antarctic Circumnavigation Expedition

Julia Schmale, Andrea Baccarini, Irina Gorodetskaya, Christel Sybille Hassler, Katherine Colby Leonard, Robin Lewis Modini, Jenny Thomas, Sebastian Johannes Heinz-Josef Landwehr, Alireza Moallemi, Fernando Perez Cruz

The Southern Ocean is a critical component of Earth's climate system, but its remoteness makes it challenging to develop a holistic understanding of its processes from the small scale to the large scale. As a result, our knowledge of this vast region remai ...

2021

Photometric characterization of multiple populations in star clusters: the impact of the first dredge-up

Carmela Lardo

The existence of star-to-star light-element abundance variations (multiple populations, MPs) in massive Galactic and extragalactic star clusters older than about 2 Gyr is by now well established. Photometry of red giant, branch (RGB) stars has been and sti ...

OXFORD UNIV PRESS2020

The Hidden Past of M92: Detection and Characterization of a Newly Formed 17 degrees Long Stellar Stream Using the Canada-France Imaging Survey

Nicolas Lawrence Etienne Longeard

We present an analysis of the structure, kinematics, and orbit of a newly found stellar stream emanating from the globular cluster M92 (NGC 6341). This stream was discovered in an improved matched-filter map of the outer Galaxy, based on a "color-color-mag ...

IOP PUBLISHING LTD2020

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

Stephan Morgenthaler, Mikaël Martino, Jean-Marie Petit, 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