Results 11 to 20 of about 296 (183)

Cepheids and other variable stars and the distance to the Galactic Centre [PDF]

Proceedings of the International Astronomical Union, 2012
AbstractWe review and discuss results of our survey of variable stars towards the Galactic Centre and their distances. In our near-infrared monitoring survey using IRSF/SIRIUS, we detected a number of Miras and Cepheids (both classical and type II) within 20 arcmin of the Galactic Centre.
openaire   +1 more source

Faint (and bright) variable stars in the satellites of the Milky Way

EPJ Web of Conferences, 2017
I describe two ongoing projects related with variable stars in the satellites of the MilkyWay. In the first project, we are searching for dwarf Cepheid stars (a.k.a δ Scuti and/or SX Phe) in some of the classical dwarf spheroidal galaxies. Our goal is to
Vivas A. Katherina
doaj   +1 more source

Nonthermal X-Rays from Pulsation-driven Shocks in Cepheids

The Astrophysical Journal, 2023
Rapid X-ray phase-dependent flux enhancement in the archetype classical Cepheid star δ Cep was observed by XMM-Newton and Chandra. We jointly analyze thermal and nonthermal components of the time-resolved X-ray spectra prior to, during, and after the ...
Federico Fraschetti, Konstantina Anastasopoulou, Jeremy J. Drake, Nancy Remage Evans   +3 more
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Synthetic Population of Binary Cepheids. II. The Effect of Companion Light on the Extragalactic Distance Scale

The Astrophysical Journal, 2023
Because of their period–luminosity relation (PLR), classical Cepheids play a key role in the calibration of the extragalactic distance scale and the determination of the Hubble–Lemaître constant H _0 .
Paulina Karczmarek, Gergely Hajdu, Grzegorz Pietrzyński, Wolfgang Gieren, Weronika Narloch, Radosław Smolec, Grzegorz Wiktorowicz, Krzysztof Belczynski   +7 more
doaj   +1 more source

The detection of a companion star to the Cepheid variable Eta Aquilae

The Astrophysical Journal, 1980
Ultraviolet spectra have been obtained with IUE of the classical Cepheid Eta Aquilae at several phases in the 7.18 day period. Significant ultraviolet emission is detected at wavelengths less than 1600 A, where little flux is expected from classical Cepheids.
J. T. Mariska, G. A. Doschek, U. Feldman
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Discovery of the Longest-period Classical Cepheid in the Milky Way

The Astrophysical Journal Letters
We report the discovery of the classical Cepheid OGLE-GD-CEP-1884 (= GDS_J1535467-555656) with the longest pulsation period known in our Galaxy. The period of 78.14 days is nearly 10 days longer than that of the previous record-holding Cepheid, S ...
I. Soszyński, D. M. Skowron, A. Udalski, P. Pietrukowicz, M. Gromadzki, M. K. Szymański, J. Skowron, P. Mróz, R. Poleski, S. Kozłowski, P. Iwanek, M. Wrona, K. Ulaczyk, K. Rybicki, M. Mróz   +14 more
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High-resolution Spectroscopic Metallicities of Milky Way Cepheid Standards and Their Impact on the Leavitt Law and the Hubble Constant

The Astrophysical Journal Letters, 2023
Milky Way Cepheid variables with accurate Hubble Space Telescope photometry have been established as standards for primary calibration of the cosmic distance ladder to achieve a percent-level determination of the Hubble constant ( H _0 ).
Anupam Bhardwaj, Adam G. Riess, Giovanni Catanzaro, Erasmo Trentin, Vincenzo Ripepi, Marina Rejkuba, Marcella Marconi, Chow-Choong Ngeow, Lucas M. Macri, Martino Romaniello, Roberto Molinaro, Harinder P. Singh, Shashi M. Kanbur   +12 more
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Implementability of Point‐of‐Care Ultrasound for Paediatric Tuberculosis Diagnosis in Resource‐Constrained Settings: Experiences and Perspectives From Uganda

Tropical Medicine &International Health, EarlyView.
ABSTRACT Introduction Childhood tuberculosis (TB) remains a significant global health challenge, with a substantial number of cases going undiagnosed, particularly among children under five. Early diagnosis and intervention are crucial to reduce TB‐associated morbidity and mortality.
Julia van den Brink, Martien Humblet, Emmanuel Nasinghe, Grace Paul Kisitu, Emmanual Tenywa, Rinn Song, Nora Engel, Francesca Wanda Basile, Else Margreet Bijker   +8 more
wiley   +1 more source

Milky Way Classical Cepheid Distances from Calibrated Infrared Period–Luminosity–Metallicity Relations

The Astrophysical Journal
Classical Cepheids (DCEPs) serve as fundamental standard candles for measuring cosmic distances and investigating the structure and evolution of the Milky Way disk.
Huajian Wang, Xiaodian Chen
doaj   +1 more source

Patterns of Drug Resistance, Drug Resistance Conferring Mutations and Genomic DNA Methylation Revealed in Mycobacterium tuberculosis From South Africa

Tropical Medicine &International Health, EarlyView.
ABSTRACT Tuberculosis remains a major public health threat globally, with drug‐resistant strains undermining treatment efficacy. We analyzed 126 Mycobacterium tuberculosis (M. tuberculosis) isolates with diverse drug resistance spectra and selected 35 for whole genome sequencing (WGS) using Illumina NextSeq, SMRT PacBio Onso and SMRT PacBio Revio ...
Unarine Matodzi, Awelani Mutshembele, Eric Mensah, Dillon Muzondiwa, Ndivhuho A. Makhado, Oleg N. Reva   +5 more
wiley   +1 more source