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Related papers: Cepheids at high angular resolution: circumstellar…

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We develop and describe a Bayesian statistical analysis to solve the surface brightness equations for Cepheid distances and stellar properties. Our analysis provides a mathematically rigorous and objective solution to the problem, including…

Astrophysics · Physics 2009-11-07 T. G. Barnes , W. H. Jefferys , J. O. Berger , P. J. Mueller , K. Orr , R. Rodriguez

The determination of pulsation mode and distance for field Cepheids is a complicated problem best resolved by a luminosity estimate. For illustration a technique based on spectroscopic luminosity discrimination is applied to the 4.47d…

Solar and Stellar Astrophysics · Physics 2015-06-16 D. G. Turner , V. V. Kovtyukh , R. E. Luck , L. N. Berdnikov

Galactic Cepheids in the vicinity of the Sun have a residual line-of-sight velocity, or gamma-velocity, which shows a systematic blueshift of about 2 km/s compared to an axisymmetric rotation model of the Milky Way. This term is either…

Astrophysics · Physics 2009-11-13 N. Nardetto , A. Stoekl , D. Bersier , T. G. Barnes

We report the detection of Cepheid variable stars in the barred spiral galaxy NGC 1365, located in the Fornax cluster, using the Hubble Space Telescope Wide Field and Planetary Camera 2. Twelve V (F555W) and four I (F814W) epochs of…

We present the results of near-infrared observations of extragalactic Cepheids made with the Near Infrared Camera and Multi-Object Spectrometer on board the Hubble Space Telescope. The variables are located in the galaxies IC 1613, IC 4182,…

Context. The circumstellar disks ejected by many rapidly rotating B stars (so-called Be stars) offer the rare opportunity of studying the structure and dynamics of gaseous disks at high spectral as well as angular resolution. Aims. This…

Solar and Stellar Astrophysics · Physics 2013-06-06 D. M. Faes , A. C. Carciofi , Th. Rivinius , S. Štefl , D. Baade , A. Domiciano de Souza

We present the analysis of multiband time-series data for a sample of 24 Cepheids in the field of the Large Magellanic Cloud cluster NGC1866. Very accurate BVI VLT photometry is combined with archival UBVI data, covering a large temporal…

Solar and Stellar Astrophysics · Physics 2016-03-09 I. Musella , M. Marconi , P. B. Stetson , G. Raimondo , E. Brocato , R. Molinaro , V. Ripepi , R. Carini , G. Coppola , A. R. Walker , D. L. Welch

Cepheid masses derived from pulsations or binary dynamics are generally lower than those derived from stellar evolution models. Recent efforts have been dedicated to investigating the effects of abundances, mass loss, rotation, convection…

Solar and Stellar Astrophysics · Physics 2020-04-14 Joyce A. Guzik , Ebraheem Farag , Jakub Ostrowski , Nancy R. Evans , Hilding Neilson , Sofia Moschou , Jeremy J. Drake

This paper introduces a statistical treatment to use Cepheid variable stars as distance indicators. The expansion rate of the Universe is also studied here through deriving the value of the Hubble constant H0. A Gaussian function…

An analytical derivation is presented for computing mass-loss rates of Cepheids by using the method of Castor, Abbott, & Klein (1975) modified to include a term for momentum input from pulsation and shocks generated in the atmosphere. Using…

Astrophysics · Physics 2009-11-13 Hilding R. Neilson , John B. Lester

We gathered more than 1130 high-resolution optical spectra for more than 250 Galactic classical Cepheids. The spectra were collected with different optical spectrographs: UVES at VLT, HARPS at 3.6m, FEROS at 2.2m MPG/ESO, and STELLA. To…

We present HST photometry of 17 Cepheids in open clusters and their mean parallaxes from Gaia EDR3. These parallaxes are more precise than those from individual Cepheids (G<8 mag) previously used to measure the Hubble constant because they…

We present homogeneous multiband (grizJHKs) time-series observations of 78 Cepheids including 49 fundamental mode variables and 29 first-overtone mode variables. These observations were collected simultaneously using the ROS2 and REMIR…

Solar and Stellar Astrophysics · Physics 2024-01-09 A. Bhardwaj , V. Ripepi , V. Testa , R. Molinaro , M. Marconi , G. De Somma , E. Trentin , I. Musella , J. Storm , T. Sicignano , G. Catanzaro

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 secondary is a B star, {\it Hubble Space Telescope} ultraviolet…

We focus on empirically measure the p-factor of a homogeneous sample of 29 LMC and 10 SMC Cepheids for which an accurate average LMC/SMC distance were estimated from eclipsing binary systems. We used the SPIPS algorithm, which is an…

Solar and Stellar Astrophysics · Physics 2017-12-06 A. Gallenne , P. Kervella , A. Mérand , G. Pietrzynski , W. Gieren , N. Nardetto , B. Trahin

Recent interferometric observations of the brightest and angularly largest classical Cepheid, L Carinae, with ESO's VLT Interferometer (VLTI) have resolved with high precision the variation of its angular diameter with phase. We compare the…

New X-ray (XMM-Newton) and JHKs (OMM) observations for members of the star cluster Alessi 95, which Turner et al.(2012) discovered hosts the classical Cepheid SU Cas, were used in tandem with UCAC3 (proper motion) and 2MASS observations to…

Cepheids play a key role in astronomy as standard candles for measuring intergalactic distances. Their distance is usually inferred from the Period-Luminosity relationship, calibrated using the semi-empirical Baade-Wesselink method. Using…

It is already accepted that Be stars are surrounded by circumstellar envelopes, which are mostly compatible with a disc geometry in Keplerian rotation. We aim to obtain a more complete characterisation of the properties of the circumstellar…

Solar and Stellar Astrophysics · Physics 2022-09-21 Y. R. Cochetti , M. L. Arias , L. S. Cidale , A. Granada , A. F. Torres

This first VELOCE data release comprises 18,225 high-precision RV measurements of 258 bona fide classical Cepheids on both hemispheres collected mainly between 2010 and 2022, alongside 1161 additional observations of 164 other stars. The…