Results 11 to 20 of about 2,384 (215)
CEPHEIDS AS DISTANCE INDICATORS: SOME CURRENT PROBLEMS
Odessa Astronomical Publications, 2017 A general review is given of the calibration of the Cepheid distance scale, with particular reference to its use in the determination of H0. Emphasis is placed on the advantage of using a galactic calibration of the Cepheid scale, rather than relying on ...
M. Feast
doaj +4 more sources
The Cepheid-Based Distance Scale
Open Astronomy, 1999 Di Benedetto G. P., Lattanzi M. G.
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INSIGHTS INTO THE CEPHEID DISTANCE SCALE [PDF]
The Astrophysical Journal, 2010 We present an investigation of Cepheid distances using theory and observations. Cepheid models indicate that the slope of the Period-Luminosity (P-L) relation covering the entire period range (0.40<= logP <=2.0) becomes steeper when moving from optical to NIR bands, and that the metallicity dependence of the slope decreases from the B- to the K ...
BONO, GIUSEPPE +3 more
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Point-of-care nucleic acid testing - a step forward in controlling the HIV epidemic: A review. [PDF]
HIV MedAbstract Introduction The HIV/AIDS epidemic, with 85.6 million infections and 40.4 million AIDS‐related deaths globally, remains a critical public health challenge. Current diagnostic methods, primarily fourth‐generation immunoassays, have limitations due to their long window periods, and most viral load assays require centralized testing protocols ...
Pinar SS +4 more
europepmc +2 more sources
Cepheid Radii and Distances [PDF]
International Astronomical Union Colloquium, 1995 Laney & Stobie (1995) (LS95) have determined Baade-Wesselink radii for 49 galactic Cepheids using BVRI and JHK photometry. Four of the possible magnitude-colour combinations were studied in detail — namely, (V,B–V), (V,V–Ic), (K,V–K) and (K,J–K). In that paper and in the present note we have used the maximum likelihood method of Balona (1977) as ...
C. D. Laney, R. S. Stobie
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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 +12 more
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Metallicity effects on the Cepheid distance scale [PDF]
Symposium - International Astronomical Union, 1991 We are undertaking empirical tests for the effects of metallicity on the zero-point of the Period-Luminosity relations for Cepheids in M31 and in the Small Magellanic Cloud (SMC), as compared to the Large Magellanic Cloud (LMC). For M31 we have used BVRI data on comparable sets of Cepheids in three radially separated, and chemically different, fields ...
Wendy L. Freedman, Barry F. Madore
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THE DISTANCE MEASUREMENT OF NGC 1313 WITH CEPHEIDS [PDF]
The Astrophysical Journal, 2015 We present the detection of Cepheids in the barred spiral galaxy NGC 1313, using the Wide Field and Planetary Camera 2 on the Hubble Space Telescpoe. Twenty B (F450W) and V (F555W) epochs of observations spanning over three weeks were obtained, on which the profile-fitting photometry of all stars in the monitored field was performed using the package ...
Gao, Qing +3 more
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The Effect of Metallicity on Cepheid‐based Distances [PDF]
The Astrophysical Journal, 2004 Accepted for publication in the Astrophysical Journal. 56 pages, 16 figures (jpg).
Sakai, Shoko +3 more
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Prevalence and Risk Factors of Elevated Alanine Aminotransferase (ALT) in 2382 Treatment-naïve HBV/HDV Co-Infected Patients. [PDF]
Liver IntABSTRACT Background Chronic hepatitis D (CHD) causes severe chronic hepatitis. Knowledge is limited about factors correlating with ALT in treatment‐naïve patients with CHD. This study analysed the pattern and determinants of ALT elevation in a large cohort of patients with CHD, including young adults, compared to propensity score‐matched (PSM) patients
Kamal H +13 more
europepmc +2 more sources