Zobrazeno 1 - 10
of 366
pro vyhledávání: '"Drake, N. A."'
Autor:
Roriz, M. P., Holanda, N., da Conceição, L. V., Junqueira, S., Drake, N. A., Sonally, A., Pereira, C. B.
A classical Local Thermodynamic Equilibrium analysis, based on high-resolution spectroscopic data, is performed for a sample of three potential barium dwarf candidates and one star already recognized as such. We derived their atmospheric parameters,
Externí odkaz:
http://arxiv.org/abs/2402.14709
Autor:
Konstantinova-Antova, R., Georgiev, S., Lèbre, A., Palacios, A., Morin, J., Bogdanovski, R., Abbott, C., Baron, F., Aurière, M., Drake, N. A., Tsvetkova, S., Josselin, E., Paladini, C., Mathias, P., Zamanov, R.
We present a detailed long-term study of the single M6 III giant RZ~Ari to obtain direct and simultaneous measurements of the magnetic field, activity indicators, and radial velocity in order to infer the origin of its activity. We study its magnetic
Externí odkaz:
http://arxiv.org/abs/2312.12549
Autor:
Hartogh, J. W. den, López, A. Yagüe, Cseh, B., Pignatari, M., Világos, B., Roriz, M. P., Pereira, C. B., Drake, N. A., Junqueira, S., Lugaro, M.
Publikováno v:
A&A 672, A143 (2023)
We aim to analyse the abundance pattern of 169 Barium (Ba) stars, using machine learning techniques and the AGB final surface abundances predicted by Fruity and Monash stellar models. We developed machine learning algorithms that use the abundance pa
Externí odkaz:
http://arxiv.org/abs/2212.03593
We present detailed chemical compositions of four stars on the first-ascent red giant branch that are classified as chemically peculiar, but lack comprehensive analyses at high spectral resolution. For BD+03{\deg}2688, HE 0457-1805, HE 1255-2324, and
Externí odkaz:
http://arxiv.org/abs/2211.08627
Autor:
Cseh, B., Világos, B., Roriz, M. P., Pereira, C. B., D'Orazi, V., Karakas, A. I., Soós, B., Drake, N. A., Junqueira, S., Lugaro, M.
Publikováno v:
A&A 660, A128 (2022)
Barium (Ba) stars are polluted by material enriched in the slow neutron capture (s-process) elements synthesised in the interior of their former asymptotic giant branch (AGB) companion star, which is now a white dwarf. We compare individual Ba star a
Externí odkaz:
http://arxiv.org/abs/2201.13379
Autor:
Roriz, M. P., Lugaro, M., Pereira, C. B., Sneden, C., Junqueira, S., Karakas, A. I., Drake, N. A.
New elemental abundances for the neutron-capture elements Sr, Nb, Mo, Ru, La, Sm, and Eu are presented for a large sample of 180 barium (Ba) giant stars, a class of chemically peculiar objects that exhibit in their spectra enhancements of the element
Externí odkaz:
http://arxiv.org/abs/2108.08132
Publikováno v:
Proceedings of the International Astronomical Union, IAU Symposium, Volume 332, pp. 237-241 (2018)
The element boron belongs, together with lithium and beryllium, to a known trio of important elements for the study of evolutionary processes in low mass stars. Because B is the least fragile of this trio to be destroyed in the stellar interiors, it
Externí odkaz:
http://arxiv.org/abs/1911.12856
We present a new abundance analysis of HD 55496, previously known as a metal-poor barium star. We found that HD 55496 has a metallicity [Fe/H] $=-1.55$ and is s-process enriched. We find that HD 55496 presents four chemical peculiarities: (i) a Na-O
Externí odkaz:
http://arxiv.org/abs/1905.08141
Autor:
Järvinen, S. P., Carroll, T. A., Hubrig, S., Ilyin, I., Schöller, M., Drake, N. A., Pogodin, M. A.
We present longitudinal magnetic field measurements $\langle B_z \rangle$ for the Herbig Ae primary and the T Tauri secondary in the SB2 system HD 104237. These measurements were carried out using high spectral resolution observations obtained with t
Externí odkaz:
http://arxiv.org/abs/1905.05586
Autor:
Järvinen, S. P., Carroll, T. A., Hubrig, S., Ilyin, I., Schöller, M., Castelli, F., Hummel, C. A., Petr-Gotzens, M. G., Korhonen, H., Weigelt, G., Pogodin, M. A., Drake, N. A.
Publikováno v:
2018, ApJL, 858, L18
We report the detection of weak mean longitudinal magnetic fields in the Herbig Ae double-lined spectroscopic binary AK Sco and in the presumed spectroscopic Herbig Ae binary HD95881 using observations with the High Accuracy Radial velocity Planet Se
Externí odkaz:
http://arxiv.org/abs/1805.04701