Stellar atmospheres separate the hot and dense stellar interiors from the emptiness of space. Radiation escapes from the outermost layers of a star, carrying...
The shell elliptical galaxy NGC 2865: evolutionary population synthesis of a kinematically distinct core
We report on the discovery of a rapidly corotating stellar and gas component in the nucleus of the shell elliptical NGC 2865. The stellar component extends ~ 0...
The short orbital period binary star at the heart of the planetary nebula M 3-1★
We present the discovery of a 3h5m orbital-period binary star at the heart of the planetary nebula M 3-1 - the shortest period photometrically variable central...
The shortest period detached binary white dwarf system
We identify SDSS J010657.39-100003.3 (hereafter J0106-1000) as the shortest period detached binary white dwarf (WD) system currently known. We targeted J0106...
The shortest period detached white dwarf + main-sequence binary
We present high-speed ULTRACAM and SOFI photometry and X-shooter spectroscopy of the recently discovered 94-min orbital period eclipsing white dwarf/main...
The sigma Orionis substellar population. VLT/FORS spectroscopy and 2MASS photometry
VLT/FORS spectroscopy and 2MASS near-infrared photometry, together with previously known data, have been used to establish the membership and the properties of...
The signal of decaying dark matter with hydrodynamical simulations
Dark matter particles may decay, emitting photons. Drawing on the EAGLE family of hydrodynamical simulations of galaxy formation - including the APOSTLE and C...
The signature of chromospheric heating in Ca II H spectra
Context: The heating process that balances the solar chromospheric energy losses has not yet been determined. Conflicting views exist on the source of the...
The signature of high-velocity gas in the spectra of NGC 4151
The multiwavelength emission spectrum and associated velocity field of the Seyfert prototype NGC 4151 is modeled. Since the thirties NGC 4151 has been the...