Buscar
Mostrando ítems 1-10 de 246
Observations of the ultraviolet-bright star Y453 in the globular cluster M4 (NGC 6121)
(IOP Publishing, 2017-09)
We present a spectral analysis of the UV-bright star Y453 in M4. Model fits to the star´s optical spectrum yield Teff ∼ 56,000 K. Fits to the star´s FUV spectrum, obtained with the Cosmic Origins Spectrograph on board the ...
The Ultraviolet Radiation Environment around M dwarf Exoplanet Host Stars
(IOP Publishing, 2013-02)
The spectral and temporal behavior of exoplanet host stars is a critical input to models of the chemistry and evolution of planetary atmospheres. Ultraviolet photons influence the atmospheric temperature profiles and ...
Observations of the Ultraviolet-bright Star Barnard 29 in the Globular Cluster M13 (NGC 6205)
(IOP Publishing, 2019-03-20)
We have analyzed spectra from FUSE, COS, GHRS, and Keck HIRES of the UV-bright star Barnard 29 in M13 (NGC 6205). By comparing the photospheric abundances derived from multiple ionization states of C, N, O, Si, and S, we ...
Horizontal Branch Stars and the Ultraviolet Universe
(2009)
Extremely hot horizontal branch (HB) stars and their progeny are widely considered to be responsible for the ``ultraviolet upturn'' (or UVX) phenomenon observed in elliptical galaxies and the bulges of spirals. Yet, the ...