Zobrazeno 1 - 10
of 377
pro vyhledávání: '"Andersen, Johannes"'
Publikováno v:
Astronomy & Astrophysics, Volume 647, March 2021
Scaling relations are very useful tools for estimating unknown stellar quantities. Within this framework, eclipsing binaries are ideal for this goal because their mass and radius are known with a very good level of accuracy, leading to improved const
Externí odkaz:
http://arxiv.org/abs/2103.11044
Publikováno v:
A&A 624, A88 (2019)
Context: One of the greatest uncertainties in modelling the mass-exchange phases during the evolution of a binary system is the amount of mass and angular momentum that has been lost from the system. To constrain this problem, a favourable, evolved a
Externí odkaz:
http://arxiv.org/abs/1903.06711
Autor:
Hansen, Camilla J., Hansen, Terese T., Koch, Andreas, Beers, Tim C., Nordström, Birgitta, Placco, Vinicius M., Andersen, Johannes
Publikováno v:
A&A 623, A128 (2019)
Carbon-enhanced metal-poor (CEMP) stars span a wide range of stellar populations, from bona fide second-generation stars to later forming stars that provide excellent probes of, e.g., binary mass transfer. Here we analyse 11 metal-poor stars of which
Externí odkaz:
http://arxiv.org/abs/1901.05968
The oldest stars in the universe retain to a great extent detailed information on the chemical composition of the interstellar medium at the time of their birth. Hence the earliest phases of Galactic chemical evolution and nucleosynthesis in the earl
Externí odkaz:
http://arxiv.org/abs/1301.7208
Autor:
Hansen, Terese, Andersen, Johannes, Nordström, Birgitta, Buchhave, Lars A., Beers, Timothy C.
A few rare halo giants in the range [Fe/H] $\simeq -2.9\pm0.3$ exhibit {\it r}-process element abundances that vary as a group by factors up to [$r$/Fe] $\sim80$, relative to those of the iron peak and below. Yet, the astrophysical production site of
Externí odkaz:
http://arxiv.org/abs/1110.4536
An overview of the Nordic Optical Telescope (NOT) is presented. Emphasis is on current capabilities of direct interest to the scientific user community, including instruments. Educational services and prospects and strategies for the future are discu
Externí odkaz:
http://arxiv.org/abs/0901.4015
Autor:
Beers, Timothy C., Flynn, Chris, Rossi, Silvia, Sommer-Larsen, Jesper, Wilhelm, Ronald, Marsteller, Brian, Lee, YoungSun, De Lee, Nathan, Krugler, Julie, Deliyannis, Constantine P., Zickgraf, Franz-Josef, Holmberg, Johan, Onehag, Anna, Eriksson, Anders, Terndrup, Donald M., Salim, Samir, Andersen, Johannes, Nordstrom, Birgitta, Christlieb, Norbert, Frebel, Anna
We report broadband UBV and/or BVRI CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field horizontal-branch or other A-type stars (FHB/A, N = 576),
Externí odkaz:
http://arxiv.org/abs/astro-ph/0610018