The helium-rich subdwarf CPD−20°1123: a post-common-envelope binary evolving on to the extended horizontal branch

Autor: L. Classen, Stephan Geier, N. Naslim, Vincent M. Woolf, N. T. Behara, C. S. Jeffery

Publikováno v: Monthly Notices of the Royal Astronomical Society. 423:3031-3038

Subluminous B stars come in a variety of flavours including single stars, close and wide binaries, and pulsating and non-pulsating variables. A majority have helium-poor surfaces (helium by number nHe 90%). A small number have an intermediate surface

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::c5af97597c53adb493696ac3326aa12b
https://doi.org/10.1111/j.1365-2966.2012.21012.x

Abundance analyses of helium-rich subluminous B stars

Autor: N. Naslim, C. S. Jeffery, Timur Şahin, A. Ahmad, N. T. Behara

Publikováno v: Monthly Notices of the Royal Astronomical Society. 409:582-590

The connection between helium-rich hot subdwarfs of spectral types O and B (He-sdB) has been relatively unexplored since the latter were found in significant numbers in the 1980's. In order to explore this connection further, we have analysed the sur

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::39578b1a44461d790f73bd8d9a08da13
https://doi.org/10.1111/j.1365-2966.2010.17324.x

Main-sequence and sub-giant stars in the globular cluster NGC 6397: The complex evolution of the lithium abundance

Autor: Roger Cayrel, Elisabetta Caffau, Matthias Steffen, Luca Sbordone, J. I. González Hernández, H.-G. Ludwig, N. T. Behara, Piercarlo Bonifacio, Simone Zaggia

Publikováno v: Proceedings of the International Astronomical Union. 5:257-261

Thanks to the high multiplex and efficiency of Giraffe at the VLT we have been able for the first time to observe the Li I doublet in the Main Sequence (MS) stars of a Globular Cluster. At the same time we observed Li in a sample of Sub-Giant (SG) st

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fa08ac555e80cd97deb4c79a14f945b1
https://doi.org/10.1017/s1743921310004217

LTE model atmospheres with new opacities

Autor: N. T. Behara, C. S. Jeffery

Publikováno v: Astronomy & Astrophysics. 451:643-650

We describe an opacity sampled version of the LTE model atmosphere code STERNE with revised continuous opacities. In particular, we examine the results of replacing the existing treatment of the continuous opacities which followed the method of Kuruc

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::55525e4e048b4b9f725963666ea21f06
https://doi.org/10.1051/0004-6361:20053978

Extensive study of HD 25558, a long-period double-lined binary with two SPB components

Autor: Simone Scaringi, S. Honda, Patricia Lampens, Paul G. Beck, Thomas Kallinger, Michael H. Williamson, R. J. Dukes, Gregory W. Henry, B. G. Castanheira, Osamu Hashimoto, H. Van Winckel, C. A. Engelbrecht, Sophie Saesen, Maryline Briquet, K. R. Pollard, M. Vučković, J. Menu, P. De Cat, Alex Lobel, Zs. Bognár, Holger Lehmann, Eiji Kambe, Shoufeng Yang, P. L. Cottrell, Coralie Neiner, Ádám Sódor, P. Mathias, E. Brunsden, Jaymie M. Matthews, R. J. Czanik, Jian-Ning Fu, P. M. Kilmartin, N. T. Behara, Duncan J. Wright, F. Maisonneuve

Publikováno v: Monthly Notices of the Royal Astronomical Society
Monthly Notices of the Royal Astronomical Society, Oxford University Press (OUP): Policy P-Oxford Open Option A, 2014, 438 (4), pp.3535-3556. ⟨10.1093/mnras/stt2466⟩
Monthly Notices of the Royal Astronomical Society, 2014, 438 (4), pp.3535-3556. ⟨10.1093/mnras/stt2466⟩

We carried out an extensive observational study of the Slowly Pulsating B (SPB) star, HD 25558. The ~2000 spectra obtained at different observatories, the ground-based and MOST satellite light curves revealed that this object is a double-lined spectr

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c9baaf8a2ed3d9118277593c659f9a58
http://arxiv.org/abs/1312.6307