Zobrazeno 1 - 10
of 395
pro vyhledávání: '"Heber Ulrich"'
Autor:
Heber, Ulrich
Hot subdwarf (SD) stars are the stripped cores of red giant stars in transition to the white dwarf sequence. The B-type subdwarfs (sdB) are powered by helium fusion in the core, more evolved ones (sdO) by shell burning. Low mass SDs may evolve throug
Externí odkaz:
http://arxiv.org/abs/2410.11663
Publikováno v:
A&A 687, A165 (2024)
The Archives of Photographic PLates for Astronomical USE (APPLAUSE) project is aimed at digitising astronomical photographic plates from three major German plate collections, making them accessible through integration into the International Virtual O
Externí odkaz:
http://arxiv.org/abs/2404.17355
Autor:
Culpan, Richard, Dorsch, Matti, Geier, Stephan, Pelisoli, Ingrid, Heber, Ulrich, Kubatova, Brankica, Cabezas, Mauricio
Context. Stars that are found on the blue horizontal-branch (BHB) have evolved from low-mass stars that have completed their core hydrogen burning main sequence stage and have undergone the helium flash at the end of their red-giant phase. The fact t
Externí odkaz:
http://arxiv.org/abs/2402.09779
Autor:
Wolz Maximilian, Kupfer Thomas, Drechsel Horst, Heber Ulrich, Irrgang Andreas, Hermes J.J., Bloemen Steven, Levitan David, Dhillon Vik, Marsh TomR.
Publikováno v:
Open Astronomy, Vol 27, Iss 1, Pp 80-90 (2018)
HW Vir systems are rare eclipsing binary systems including a subdwarf B star (sdB) with a faint companion, mostly M-dwarfs. Up to now, 19 HW Vir systems have been published, three of them with substellar companions. We report the spectroscopic as wel
Externí odkaz:
https://doaj.org/article/f6943f11b19f408a8258c559bf7b2871
Autor:
Schindewolf Markus, Németh Peter, Heber Ulrich, Battich Tiara, Bertolami Marcelo M. Miller, Latour Marilyn
Publikováno v:
Open Astronomy, Vol 27, Iss 1, Pp 27-34 (2018)
The chemical composition of helium-rich hot subluminous O stars plays an important role to understand and model their formation history. We present a spectroscopic analysis of four He-sdO stars,CD-31° 4800, [CW83] 0904- 02, LSS 1274 and LS IV +10°
Externí odkaz:
https://doaj.org/article/0089a23068ae4c538856cf26d30cfcd0
Publikováno v:
Open Astronomy, Vol 27, Iss 1, Pp 35-43 (2018)
Photometric surveys at optical, ultraviolet, and infrared wavelengths provide ever-growing datasets as major surveys proceed. Colour-colour diagrams are useful tools to identify classes of star and provide large samples. However, combining all photom
Externí odkaz:
https://doaj.org/article/25545f25ad704f4eaaf9bb77285ef5ea
Publikováno v:
Open Astronomy, Vol 27, Iss 1, Pp 19-26 (2018)
The bright sdO star HD127493 is known to be of mixed H/He composition and excellent archival spectra covering both optical and ultraviolet ranges are available. UV spectra play a key role as they give access to many chemical species that do not show
Externí odkaz:
https://doaj.org/article/38e39bbe444e41b695783c2c05142993
Publikováno v:
Open Astronomy, Vol 26, Iss 1, Pp 139-151 (2017)
Decades ago, 3He isotope enrichment in helium-weak B-type main-sequence, in blue horizontal branch and in hot subdwarf B (sdB) stars, i.e., helium-core burning stars of the extreme horizontal branch, were discovered. Diffusion processes in the atmosp
Externí odkaz:
https://doaj.org/article/19c366c6b1c741db8d7af608de575ad7
Autor:
Geier Stephan, Østensen Roy H., Nemeth Peter, Heber Ulrich, Gentile Fusillo Nicola P., Gänsicke Boris T., Telting John H., Green Elizabeth M., Schaffenroth Johannes
Publikováno v:
Open Astronomy, Vol 26, Iss 1, Pp 164-168 (2017)
In preparation for the upcoming all-sky data releases of the Gaia mission, we compiled a catalog of known hot subdwarf stars and candidates drawn from the literature and yet unpublished databases. The catalog contains 5613 unique sources and provides
Externí odkaz:
https://doaj.org/article/96f10bfd6b0c48e6a632485a976e80e2
Publikováno v:
Open Astronomy, Vol 27, Iss 1, Pp 95-97 (2018)
We present a status report of our spectroscopic analysis of subdwarf binaries consisting of a subdwarf and a F/G/K-type main-sequence companion. These systems selected from SDSS photometry show significant excess in the (infra-)red which can not be e
Externí odkaz:
https://doaj.org/article/ceff13271eb34ecd8e06b7af3c7e81f2