Publications (43)
Inspecting the Cepheid parallax of pulsation using Gaia EDR3 parallaxes. Projection factor and period-luminosity and period-radius relations
Boris Trahin, Louise Breuval, Pierre Kervella +5
As primary anchors of the distance scale, Cepheid stars play a crucial role in our understanding of the distance scale of the Universe because of their period-luminosity relation.…
Thermal infrared properties of classical and type II Cepheids Diffraction limited 10 microns imaging with VLT/VISIR
Alexandre Gallenne, Pierre Kervella, Antoine Mérand
We present new thermal IR photometry and spectral energy distributions (SEDs) of eight classical Cepheids (type I) and three type II Cepheids, using VISIR thermal IR photometric me…
The circumstellar envelopes of the Cepheids L Car and RS Pup - Comparative study in the infrared with Spitzer, VLT/VISIR and VLTI/MIDI
Pierre Kervella, Antoine Mérand, Alexandre Gallenne
[Abridged] - Context: Circumstellar envelopes (CSEs) around Cepheids are particularly interesting as they could impact the Cepheid distance scale, and imply stellar mass loss. Aims…
X-rays in Cepheids: XMM-Newton Observations of Aql
Nancy Remage Evans, Ignazio Pillitteri, Pierre Kervella +13
X-ray bursts have recently been discovered in the Cepheids Cep and Dor modulated by the pulsation cycle. We have obtained an observation of the Cepheid Aql with the…
A distance determination to the Small Magellanic Cloud with an accuracy of better than 2 percent based on late-type eclipsing binary stars
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +17
We present a new study of late-type eclipsing binary stars in the Small Magellanic Cloud (SMC) undertaken with the aim of improving the distance determination to this important gal…
Spatially extended emission around the Cepheid RS Puppis in near-infrared hydrogen lines. Adaptive optics imaging with VLT/NACO
Alexandre Gallenne, Antoine Mérand, Pierre Kervella +1
It has been recently discovered that Cepheids harbor circumstellar envelopes (CSEs). RS Pup is the Cepheid that presents the most prominent circumstellar envelope known, the origin…
Mass of Cepheid V350 Sgr Incorporating Interferometry and the Companion Mass
Nancy Remage Evans, Alexandre Gallenne, Pierre Kervella +8
The system V350 Sgr has a classical Cepheid for the primary. Interferometry is presented for the system and the full orbit is determined. The mass of the companion has been determi…
Science cases for a visible interferometer
Philippe Stee, France Allard, Myriam Benisty +54
High spatial resolution is the key for the understanding various astrophysical phenomena. But even with the future E-ELT, single dish instruments are limited to a spatial resolutio…
The Orbit and Mass of the Cepheid AW Per
Nancy Remage Evans, Alexandre Gallenne, Pierre Kervella +17
The Cepheid AW Per is a component in a multiple system with a long period orbit. The radial velocities of Griffin (2016) cover the 38 year orbit well. An extensive program of inter…
Toward a renewed Galactic Cepheid distance scale from Gaia and optical interferometry
Pierre Kervella, Antoine Mérand, Alexandre Gallenne +9
Through an innovative combination of multiple observing techniques and mod- eling, we are assembling a comprehensive understanding of the pulsation and close environment of Cepheid…
The Araucaria Project. The distance to the Small Magellanic Cloud from late-type eclipsing binaries
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +12
We present a distance determination to the Small Magellanic Cloud (SMC) based on an analysis of four detached, long period, late type eclipsing binaries discovered by the OGLE Surv…
The Araucaria Project: A study of the classical Cepheid in the eclipsing binary system OGLE LMC562.05.9009 in the Large Magellanic Cloud
Wolfgang Gieren, Bogumil Pilecki, Grzegorz Pietrzynski +26
We present a detailed study of the classical Cepheid in the double-lined, highly eccentric eclipsing binary system OGLE-LMC562.05.9009. The Cepheid is a fundamental mode pulsator w…
Observational calibration of the projection factor of Cepheids. II. Application to nine Cepheids with HST/FGS parallax measurements
Joanne Breitfelder, Antoine Mérand, Pierre Kervella +4
The distance to pulsating stars is classically estimated using the parallax-of-pulsation (PoP) method, which combines spectroscopic radial velocity measurements and angular diamete…
Optical interferometry and Gaia parallaxes for a robust calibration of the Cepheid distance scale
Pierre Kervella, Antoine Mérand, Alexandre Gallenne +5
We present the modeling tool we developed to incorporate multi-technique observations of Cepheids in a single pulsation model: the Spectro-Photo-Interferometry of Pulsating Stars (…
The Baade-Wesselink projection factor of RR Lyrae stars -- Calibration from OHP/SOPHIE spectroscopy and Gaia DR3 parallaxes
Garance Bras, Pierre Kervella, Boris Trahin +10
The application of the parallax of pulsation (PoP) technique to determine distances of pulsating stars implies the use of a scaling parameter, the projection factor (p-factor), req…
Distance to the Globular Cluster M 3 from the Infrared Surface Brightness Technique applied to RR Lyrae stars
BartÅomiej Zgirski, Wolfgang Gieren, Grzegorz PietrzyÅski +10
The Infrared Surface Brightness (IRSB) technique is a specific application of the Baade-Wesselink method. Given a proper calibration, well covered optical and near-infrared photome…
Observational calibration of the projection factor of Cepheids I. The Type II Cepheid kappa Pavonis
Joanne Breitfelder, Pierre Kervella, Antoine Mérand +5
The distances of pulsating stars, in particular Cepheids, are commonly measured using the parallax of pulsation technique. The different versions of this technique combine measurem…
Cepheid distances from the Baade-Wesselink method
Wolfgang Gieren, Jesper Storm, Nicolas Nardetto +5
Recent progress on Baade-Wesselink (BW)-type techniques to determine the distances to classical Cepheids is reviewed. Particular emphasis is placed on the near-infrared surface-bri…
The Surface Brightness--Color Relations Based on Eclipsing Binary Stars: Toward Precision Better than 1% in Angular Diameter Predictions
Dariusz Graczyk, Piotr Konorski, Grzegorz Pietrzynski +7
In this study we investigate the calibration of surface brightness--color (SBC) relations based solely on eclipsing binary stars. We selected a sample of 35 detached eclipsing bina…
The Components of Cepheid Systems: The FN Vel System
Nancy Remage Evans, Pierre Kervella, Joanna Kuraszkiewicz +8
Cepheid masses continue to be important tests of evolutionary tracks for intermediate mass stars as well as important predictors of their future fate. For systems where the seconda…
Consistent radial velocities of classical Cepheids from the cross-correlation technique
Simon Borgniet, Pierre Kervella, Nicolas Nardetto +11
Accurate radial velocities () of Cepheids are mandatory within the context of distance measurements via the Baade-Wesselink technique. The most common de…
The Orbit of the Close Companion of Polaris: Hubble Space Telescope Imaging 2007 to 2014
Nancy Remage Evans, Margarita Karovska, Howard E. Bond +6
As part of a program to determine dynamical masses of Cepheids, we have imaged the nearest and brightest Cepheid, Polaris, with the Hubble Space Telescope Wide Field Planetary Came…
V659 Cen: System Parameters Updated
Nancy Remage Evans, Charles Proffitt, Pierre Kervella +8
V659 Cen is a classical Cepheid which is part of a multiple system. Previous observations have shown that a hot companion dominates an ultraviolet spectrum and a cooler main sequen…
Inspecting the Cepheid distance ladder: The Hubble Space Telescope distance to the SNIa host galaxy NGC 5584
Behnam Javanmardi, Antoine Mérand, Pierre Kervella +7
The current tension between the direct and the early Universe measurements of the Hubble Constant, , requires detailed scrutiny of all the data and methods used in the studies…
The Leavitt law of Milky Way Cepheids from Gaia DR2 static companion parallaxes
Louise Breuval, Pierre Kervella, Frédéric Arenou +13
Classical Cepheids (CCs) are at the heart of the empirical extragalactic distance ladder. Milky Way CCs are the only stars of this class accessible to trigonometric parallax measur…
Cepheids with giant companions. II. Spectroscopic confirmation of nine new double-lined binary systems composed of two Cepheids
BogumiÅ Pilecki, Ian B. Thompson, Felipe Espinoza-Arancibia +13
Binary Cepheids with giant companions are crucial for studying the physical properties of Cepheid variables, providing the best means to measure their masses. Systems composed of t…
Observational calibration of the projection factor of Cepheids - III. The long-period Galactic Cepheid RS Puppis
Pierre Kervella, Boris Trahin, Howard E. Bond +10
The projection factor (p-factor) is an essential component of the classical Baade-Wesselink (BW) technique, that is commonly used to determine the distances to pulsating stars. It…
Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids: Final Results
Nancy Remage Evans, H. Moritz Guenther, Howard E. Bond +13
Cepheids in multiple systems provide information on the outcome of the formation of massive stars. They can also lead to exotic end-stage objects. This study concludes our survey o…
Cepheid distances from the SpectroPhoto-Interferometry of Pulsating Stars (SPIPS) - Application to the prototypes delta Cep and eta Aql
Antoine Merand, Pierre Kervella, Joanne Breitfelder +8
The parallax of pulsation, and its implementations such as the Baade-Wesselink method and the infrared surface bright- ness technique, is an elegant method to determine distances o…
An edge-on translucent dust disk around the nearest AGB star L2 Puppis - VLT/NACO spectro-imaging from 1.04 to 4.05 microns and VLTI interferometry
Pierre Kervella, Miguel Montargès, Stephen T. Ridgway +6
As the nearest known AGB star (d=64pc) and one of the brightest (mK-2), L2 Pup is a particularly interesting benchmark object to monitor the final stages of stellar evolution. We r…
The late type eclipsing binaries in the Large Magellanic Cloud: catalogue of fundamental physical parameters
Dariusz Graczyk, Grzegorz Pietrzynski, Ian B. Thompson +29
We present a determination of precise fundamental physical parameters of twenty detached, double- lined, eclipsing binary stars in the Large Magellanic Cloud (LMC) containing G- or…
Status and new operation modes of the versatile VLT/NACO
Julien H. V. Girard, Markus Kasper, Sascha P. Quanz +14
This paper aims at giving an update on the most versatile adaptive optics fed instrument to date, the well known and successful NACO . Although NACO is only scheduled for about two…
The Orbit and Dynamical Mass of Polaris: Observations with the CHARA Array
Nancy Remage Evans, Gail Schaefer, Alexandre Gallenne +19
The 30 year orbit of the Cepheid Polaris has been followed with observations by the CHARA Array (Center for High Angular Resolution Astronomy) from 2016 through 2021. An additional…
VLTI/GRAVITY upper limit on near-infrared emission from the nearby 33 Msun black hole Gaia BH3
Pierre Kervella, Pasquale Panuzzo, Alexandre Gallenne +11
The recent astrometric discovery of the nearby (590 pc) massive () dormant black hole candidate Gaia BH3 offers the possibility to angularly resolve the black hole from…
Planet Formation Imager (PFI): science vision and key requirements
Stefan Kraus, John D. Monnier, Michael J. Ireland +75
The Planet Formation Imager (PFI) project aims to provide a strong scientific vision for ground-based optical astronomy beyond the upcoming generation of Extremely Large Telescopes…
The Near Infrared Imager and Slitless Spectrograph for JWST -- V. Kernel Phase Imaging and Data Analysis
Jens Kammerer, Rachel A. Cooper, Thomas Vandal +26
Kernel phase imaging (KPI) enables the direct detection of substellar companions and circumstellar dust close to and below the classical (Rayleigh) diffraction limit. We present a…
Cepheids at high angular resolution: circumstellar envelope and pulsation
Alexandre Gallenne
In 2005, interferometric observations with VLTI/VINCI and CHARA/FLUOR revealed the existence of a circumstellar envelope (CSE) around some Cepheids. This surrounding material is pa…
An absolute calibration of the near-infrared Period-Luminosity Relations of Type II Cepheids in the Milky Way and in the Large Magellanic Cloud
Piotr Wielgórski, Grzegorz PietrzyÅski, BogumiÅ Pilecki +29
We present time-series photometry of 21 nearby Type II Cepheids in the near-infrared J, H and Ks passbands. We use this photometry, together with the Third Gaia Early Data Release…
Testing systematics of Gaia DR2 parallaxes with empirical surface brightness -- color relations applied to eclipsing binaries
Dariusz Graczyk, Grzegorz Pietrzynski, Wolfgang Gieren +18
Using a sample of 81 galactic, detached eclipsing binary stars we investigated the global zero-point shift of their parallaxes with the Gaia Data Release 2 (DR2) parallaxes. The st…
Empirical H- and K-band Limb Darkening for 31 CHARA Stars: A Near-Infrared Benchmark for Stellar-Atmosphere Models
Narsireddy Anugu, John D. Monnier, Antoine Mérand +9
Limb darkening, the decrease in stellar intensity from the disk center to the limb, encodes the temperature structure and opacity of stellar atmospheres. Direct spatially resolved…
The Milky Way Cepheid Leavitt law based on Gaia DR2 parallaxes of companion stars and host open cluster populations
Louise Breuval, Pierre Kervella, Richard I. Anderson +12
Classical Cepheids provide the foundation for the empirical extragalactic distance ladder. Milky Way Cepheids are the only stars in this class accessible to trigonometric parallax…
The Araucaria Project: High-precision Cepheid astrophysics from the analysis of variables in double-lined eclipsing binaries
BogumiÅ Pilecki, Wolfgang Gieren, Grzegorz PietrzyÅski +15
Based on new observations and improved modeling techniques, we have reanalyzed seven Cepheids in the Large Magellanic Cloud. Improved physical parameters have been determined for t…
Pre-nova Observations of T CrB: A view from the CHARA Array
Ryan Norris, Narsireddy Anugu, Thomas Gaudin +38
T CrB is a symbiotic recurrent nova consisting of a red giant and white dwarf with recent eruptions in 1866 and 1946 and an anticipated eruption in the mid 2020s. We report CHARA A…