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Related papers: Cepheid Parallaxes and the Hubble Constant

200 papers

Previous nonlinear fundamental pulsation models for classical Cepheids with metal content Z <= 0.02 are implemented with new computations at super-solar metallicity (Z=0.03, 0.04) and selected choices of the helium-to-metal enrichment ratio…

Astrophysics · Physics 2009-11-07 G. Fiorentino , F. Caputo , M. Marconi , I. Musella

The distance to NGC 7331 has been derived from Cepheid variables observed with HST/WFPC2, as part of the Extragalactic Distance Scale Key Project. Multi-epoch exposures in F555W (V) and F814W (I), with photometry derived independently from…

We present homogeneous and accurate iron abundances for 42 Galactic Cepheids based on high-spectral resolution (R~38,000) high signal-to-noise ratio (SNR>100) optical spectra collected with UVES at VLT (128 spectra). The above abundances…

We present results based on a Baade-Wesselink analysis of Cepheids in the Small Magellanic Cloud. The Baade-Wesselink analysis provides individual luminosities for these metal-poor Cepheids which combined with recent Baade-Wesselink results…

Astrophysics · Physics 2007-05-23 Jesper Storm , Bruce W. Carney , Anne M. Fry

We investigate the influence of blending on the Cepheid distance scale. Blending leads to systematically low distances to galaxies observed with HST, and therefore to systematically high estimates of the Hubble constant H_0. We select a…

Astrophysics · Physics 2007-05-23 K. Z. Stanek , A. Udalski

A measurement of the distance to Virgo Cluster by a direct method along with a realistic error analysis is important for a reliable determination of the value of Hubble Constant. Cepheid variables in the face-on spiral M100 in the Virgo…

Astrophysics · Physics 2007-05-23 D. Narasimha , Anwesh Mazumdar

We present HST photometry of a selected sample of 50 long-period, low-extinction Milky Way Cepheids measured on the same WFC3 F555W, F814W, and F160W-band photometric system as extragalactic Cepheids in SN Ia hosts. These bright Cepheids…

We reanalyse observations of type Ia supernovae (SNe) and Cepheids used in the local determination of the Hubble constant and find strong evidence that SN standardisation in the calibration sample (galaxies with observed Cepheids) require a…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-15 Radosław Wojtak , Jens Hjorth

We present the results of non-linear pulsation modelling of 20 bump Cepheids in the LMC. By obtaining a optimal fit to the observed V,R MACHO lightcurves we have placed tight constraints on stellar parameters of M, L, Teff and well as…

Astrophysics · Physics 2009-11-07 Stefan C. Keller , Peter R. Wood

Preliminary evidence is presented reaffirming that SX Phe, RR Lyrae, and Type II Cepheid variables may be characterized by a common Wesenheit period-magnitude relation, to first order. Reliable distance estimates to RR Lyrae variables and…

Astrophysics of Galaxies · Physics 2014-11-20 Daniel J. Majaess

We present measurements of 68 classical Cepheids with periods from 10 to 78 days observed in the near-infrared by the PHAT Program using the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST). The combination of HST's resolution…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Adam G. Riess , Juergen Fliri , David Valls-Gabaud

(ABRIDGED) We have applied the near-IR Barnes-Evans realization of the Baade-Wesselink method as calibrated by Fouque & Gieren (1997) to five metal-poor Cepheids with periods between 13 and 17 days in the Small Magellanic Cloud as well as…

In this work, we updated the catalog of Galactic Cepheids with $24\mu\mathrm{m}$ photometry by cross-matching the positions of known Galactic Cepheids to the recently released MIPSGAL point source catalog. We have added 36 new sources…

Solar and Stellar Astrophysics · Physics 2015-11-04 Chow-Choong Ngeow , Saurjya Sarkar , Anupam Bhardwaj , Shashi M. Kanbur , Harinder P. Singh

Repeated imaging observations have been made of NGC 4527 with the Hubble Space Telescope between April and June 1999, over an interval of 69 days. Images were obtained on 12 epochs in the F555W band and on five epochs in the F814W band. The…

Cepheids have been observed in NGC 5236 (M 83) using the ANTU (UT1) 8.2 meter telescope of the ESO VLT with FORS1. Observations over 34 epochs in V and I have been made between January 2000 and July 2001. Twelve Cepheid candidates have…

Astrophysics · Physics 2009-11-07 Frank Thim , G. A. Tammann , A. Saha , A. Dolphin , Allan Sandage , E. Tolstoy , Lukas Labhardt

Cepheids have long been used as standard candles to determine distances around the Milky Way and to nearby galaxies. A discrepancy still remains for Hubble Constant determinations using Cepheids vs. the cosmic microwave background or…

Solar and Stellar Astrophysics · Physics 2023-07-25 Joyce A. Guzik , Jason Jackiewicz , Nancy R. Evans

This paper discusses the current uncertainties in luminosity calibration of the RR Lyrae variables. The difference in distance moduli between the SMC and LMC as derived from RR Lyrae stars and classical Cepheids is used to estimate a…

Solar and Stellar Astrophysics · Physics 2011-06-09 Michael Feast

We present new accurate Period-Luminosity (PL) and Period-Wesenheit (PW) relations in the V,J,Ks bands based on a sample of more than 4500 Cepheids in the Large Magellanic Cloud (LMC) whose photometry was obtained in the context of the…

Solar and Stellar Astrophysics · Physics 2020-03-02 V. Ripepi , R. Molinaro , M. Marconi , M. -R. L. Cioni

Recent observations of Type Ia supernovae (SNe) by SH0ES collaboration (R11 and R16) diverge from the value reported by recent CMBR observations utilising the Planck satellite and application of the $\Lambda CDM$ cosmological model by at…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Rahul Kumar Thakur , Harish Kumar , Shashikant Gupta , Dinkar Verma , Rahul Nigam

High-resolution JWST observations can test confusion-limited HST observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs…