Results 1 to 10 of about 5,135 (186)

Parameters and Pulsation Constant of Cepheid

Particles, 2023
The analysis of fifty empirical period-radius relations and forty-three empirical period-luminosity relations is performed for the Cepheids. It is found that most of these relations have significant systematic errors.
Sergei V Sinitsyn
exaly   +3 more sources

Molecular Characterization of <i>Mycobacterium tuberculosis</i> Isolates From West of Iran Using Mycobacterial Interspersed Repetitive Unit-Variable Number Tandem Repeats: A Cross-Sectional Study. [PDF]

Health Sci Rep
ABSTRACT Background and Aims Tuberculosis (TB) remains a major global health problem and poses significant challenges for diagnosis and treatment. The World Health Organization (WHO) recommends the use of molecular methods for the diagnosis and genotyping of Mycobacterium tuberculosis complex (MTBC).
Yazdanmanesh M, Tadayon K, Kazemian H, Sadouqi N, Mosavari N.   +4 more
europepmc   +2 more sources

Cepheid Variables in the LMC and SMC [PDF]

Symposium - International Astronomical Union, 1999
In this paper, we will review major new results regarding classical Cepheids, in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC). Specifically, we discuss recent work regarding multimode Cepheids and describe new observations of a W Vir star (HV 5756) and a Cepheid which are each in eclipsing binary systems.
The MACHO Collaboration, Welch, D. L., Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., Cook, K. H., Freeman, K. C., Griest, K., Kurtz, D. W., Lehner, M. J., Marshall, S. L., Minniti, D., Peterson, B. A., Pratt, M. R., Quinn, P. J., Rodgers, A. W., Rorabeck, A., Sutherland, W., Tomaney, A., Vandehei, T.   +22 more
openaire   +7 more sources

Cepheid Pulsation Theory and Multiperiodic Cepheid Variables [PDF]

International Astronomical Union Colloquium, 1976
In this review of the situation with regard to the multiperiodic Cepheid variables, our subject matter is divided into four parts. The first discusses general causes of pulsation of Cepheids and other variable stars, and their locations on the H-R diagram. For this section we draw upon the work during the past 10-15 years of J. P.
A. N. Cox, J. P. Cox
openaire   +1 more source

Metallicities of Classical Cepheids in the Inner Galactic Disk

The Astrophysical Journal, 2023
Metallicity gradients refer to the sloped radial profiles of the metallicities of gas and stars and are commonly seen in disk galaxies. A well-defined metallicity gradient of the Galactic disk is observed particularly well with classical Cepheids, which ...
Noriyuki Matsunaga, Daisuke Taniguchi, Scarlet S. Elgueta, Takuji Tsujimoto, Junichi Baba, Andrew McWilliam, Shogo Otsubo, Yuki Sarugaku, Tomomi Takeuchi, Haruki Katoh, Satoshi Hamano, Yuji Ikeda, Hideyo Kawakita, Charlie Hull, Rogelio Albarracín, Giuseppe Bono, Valentina D’Orazi   +16 more
doaj   +1 more source

M33 Cepheids from CFHT/MegaCam Survey

The Astronomical Journal, 2022
In this paper we analyze Sloan g, r, i archival imaging data of M33 taken by Hartman et al. using MegaCam at the Canada–France–Hawaii Telescope. To determine the distance to the M33 galaxy, we performed several analytical steps to identify its Cepheid ...
Samuel Adair, Chien-Hsiu Lee
doaj   +1 more source

Cepheids and Long Period Variables in M 33 [PDF]

AIP Conference Proceedings, 2009
We are conducting a long-term photometric survey of the nearby galaxy M33 to discover Cepheids, eclipsing binaries, and long-period variables. The dataset combines previously-obtained optical images from the DIRECT project with new observations acquired at the WIYN 3.5m telescope.
Anne Pellerin, Lucas M. Macri, Andrew K. Bradshaw, Krzysztof Z. Stanek, Joyce Ann Guzik, Paul A. Bradley   +5 more
openaire   +2 more sources

Recent work on Cepheid variables [PDF]

Space Science Reviews, 1980
AbstractRecent work on Cepheids is reviewed in the areas of (1) the large-amplitude mode behavior, (2) convection, and (3) Cepheid masses. Initial-value type nonlinear calculations have not yet yielded true double-mode behavior. Yet we have the beginnings of a promising theory of modal selection.
openaire   +1 more source

KIC2569073, A second Cepheid in the Kepler FOV

EPJ Web of Conferences, 2015
One particularly interesting new variable discovered via Kepler’s 200x200 pixel superstamp images is KIC2569073. With a period of 14.66 days and 0.04mag variability it is only the second Cepheid in the Kepler field, or a rotationally modulated variable ...
Drury Jason A., Kuehn Charles A., Bellamy Beau R., Stello Dennis, Bedding Timothy R.   +4 more
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
doaj   +1 more source