Zobrazeno 1 - 10
of 141
pro vyhledávání: '"Ian D. Howarth"'
Autor:
Jeremy Bailey, Fiona Lewis, Ian D. Howarth, Daniel V. Cotton, Jonathan P. Marshall, Lucyna Kedziora-Chudczer
Publikováno v:
The Astrophysical Journal, Vol 972, Iss 1, p 103 (2024)
We report high-precision, multiwavelength linear-polarization observations of the bright B9 (or A0) star ϵ Sagittarii. The polarization shows the distinctive wavelength dependence expected for a rapidly rotating star. Analysis of the polarization da
Externí odkaz:
https://doaj.org/article/6a7be5dbd6834c1890134c6ad5244e36
We report new, extremely precise, photopolarimetry of the rapidly-rotating A0 main-sequence star $\zeta$ Aql, covering the wavelength range $\sim$400--900nm, which reveals a rotationally-induced signal. We model the polarimetry, together with the flu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9771a2fefc03dd323a5be7aa075e27a6
http://arxiv.org/abs/2301.05018
http://arxiv.org/abs/2301.05018
Autor:
Fiona Lewis, Jeremy Bailey, Daniel V Cotton, Ian D Howarth, Lucyna Kedziora-Chudczer, Floor van Leeuwen
We report high-precision observations of the linear polarization of the F1$\,$III star $\theta$ Scorpii. The polarization has a wavelength dependence of the form expected for a rapid rotator, but with an amplitude several times larger than seen in ot
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::df2cbe5a2aac0177da28e76e70cebddb
http://arxiv.org/abs/2204.02719
http://arxiv.org/abs/2204.02719
Autor:
Jorick S. Vink, Sam Geen, Norbert Langer, A. Schootemeijer, Chris Evans, Paul A. Crowther, A. de Koter, D. J. Lennon, Ian D. Howarth, Karl M. Menten
Publikováno v:
Astronomy & Astrophysics, 646:A106. EDP Sciences
Massive star evolution at low metallicity is closely connected to many fields in high-redshift astrophysics, but poorly understood. The Small Magellanic Cloud (SMC) is a unique laboratory to study this because of its metallicity of 0.2 Zsol, its prox
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::04cb02488b088031e4e4b1523e14136b
https://lirias.kuleuven.be/handle/123456789/672505
https://lirias.kuleuven.be/handle/123456789/672505
Recently we have demonstrated that high-precision polarization observations can detect the polarization resulting from the rotational distortion of a rapidly rotating B-type star. Here we investigate the extension of this approach to an A-type star.
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c4d0d26be62004992c4de5ca7ede9a39
Autor:
Dominic Reeve, Ian D. Howarth
Publikováno v:
Monthly Notices of the Royal Astronomical Society. 478:3133-3137
We examine claims of strong gravity-darkening effects in the O-star components of WR+O binaries. We generate synthetic spectra for a wide range of parameters, and show that the line-width results are consistent with extensive measurements of O stars
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f7572df4fbcb5b3e235fb2668243180e
https://doi.org/10.1093/mnras/sty1296
https://doi.org/10.1093/mnras/sty1296
Autor:
Philip W. Lucas, Kimberly Bott, Lucyna Kedziora-Chudczer, Ian D. Howarth, J. H. Hough, Daniel V. Cotton, Jeremy Bailey
Publikováno v:
Nature Astronomy. 1:690-696
Polarization in stars was first predicted by Chandrasekhar [1] who calculated a substantial linear polarization at the stellar limb for a pure electron-scattering atmosphere. This polarization will average to zero when integrated over a spherical sta
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::22d2274831eeca9cf03c359fbf64b1cd
https://doi.org/10.1038/s41550-017-0238-6
https://doi.org/10.1038/s41550-017-0238-6
Autor:
Floor van Leeuwen, Ian D. Howarth
We scrutinize the Hipparcos parallax for the bright O supergiant zeta Pup, and confirm that the implied distance of 332+/-11pc appears to be reliable. We then review the implications for the star's physical parameters, and the consequences for the in
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::3aea34e2fd60be71855dc28c7ceba27d
http://arxiv.org/abs/1901.08020
http://arxiv.org/abs/1901.08020
Autor:
Guang-Wei Li, Ian D. Howarth
The ON stars are a rare subtype of O stars, of uncertain origin. We report two new, rapidly-rotating ON stars found in data acquired with the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, LAMOST. LS I +61 28 is an ON8.5 Vn dwarf with a p
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::60e9e3930da7d3ce23e66ef03dd9ca18
Autor:
Alexandre David-Uraz, Gregg A. Wade, David Asher, Coralie Neiner, Michał K. Szymański, Matt Shultz, Ian D. Howarth, Jason Grunhut, Melissa Munoz, Jorick S. Vink, Nidia Morrell, Stefano Bagnulo, Yaël Nazé, Joachim Puls, Chris Evans, Paul A. Crowther
Publikováno v:
Astronomy and Astrophysics-A&A
Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 635, pp.A163. ⟨10.1051/0004-6361/201937098⟩
Astronomy and Astrophysics-A&A, EDP Sciences, 2020, 635, pp.A163. ⟨10.1051/0004-6361/201937098⟩
Despite their rarity, massive stars dominate the ecology of galaxies via their strong, radiatively-driven winds throughout their lives and as supernovae in their deaths. However, their evolution and subsequent impact on their environment can be signi
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9d5a958ef92716e70e393a5d1a2cc7f7
https://doi.org/10.1051/0004-6361/201937098
https://doi.org/10.1051/0004-6361/201937098