Related papers: $\alpha$ Centauri A in the far infrared
We present the first derivation of a stellar flare temperature profile from single-band photometry. Stellar flare DWF030225.574-545707.45129 was detected in 2015 by the Dark Energy Camera as part of the Deeper, Wider, Faster Programme. The…
We present results from deeper {\em Chandra} observations of the southwest radio lobe of Centaurus A, first described by Kraft et al. (2003). We find that the sharp X-ray surface brightness discontinuity extends around $\sim$75% of the…
We explore imprints of the solar wind interaction with the local interstellar medium on spectral properties of the backscattered solar Ly-alpha radiation. We employ newly developed effective model for the interstellar H atom velocity…
FUSE ultraviolet spectra of 8 giant and supergiant stars reveal that high temperature (3 X 10^5 K) atmospheres are common in luminous cool stars and extend across the color-magnitude diagram from Alpha Car (F0 II) to the cool giant Alpha…
Recent observational and numerical studies show a variety of thermal structures in the solar chromosphere. Given that the thermal interplay across the transition region is a key to coronal heating, it is worth investigating how different…
Most static 1D atmosphere models in the quiet Sun predict a rise of the gas temperature at chromospheric layers, but numerical simulations only yield an increase in the brightness temperature. We investigate the thermal structure in the…
Aims. The aim of this work is to further investigate the nature of PAH excitation and emission especially in the context of tracing star formation in a variety of extragalactic environments. Here we turn our attention to the energetic…
Many chemically peculiar (CP) stars, especially the magnetic CP2 stars, show a flux depression at 5200A. The "Delta a" photometric System takes advantage of this characteristic to detect these objects in an efficient way. In addition, it is…
Elemental abundances in the solar corona are known to be different from those observed in the solar photosphere. The ratio of coronal to photospheric abundance shows a dependence on the first ionisation potential (FIP) of the element. We…
Chemically peculiar (CP) stars are unique natural laboratories for investigation of the microscopic diffusion processes of chemical elements. The element segregation under the influence of gravity and radiation pressure leads to the…
We perform a detailed X-ray study of the filaments surrounding the brightest cluster galaxies in a sample of nearby galaxy clusters using deep Chandra observations, namely the Perseus, Centaurus and Virgo clusters, and Abell 1795. We…
M dwarf's atmosphere is expected to be highly magnetized. The magnetic energy can be responsible for heating the stellar chromosphere and corona, and driving the stellar wind. The nonlinear propagation of Alfv\'en wave is the promising…
Recent improvements in the modeling of solar convection and line formation led to downward revisions of the solar photospheric abundances of the lighter elements, which in turn led to changes in the radiative opacity of the solar interior…
ALMA observations of the Sun at mm-$\lambda$ offer a unique opportunity to investigate the temperature structure of the solar chromosphere. In this article we expand our previous work on modeling the chromospheric temperature of the quiet…
Proxima Centauri b, an Earth-size planet in the habitable zone of our nearest stellar neighbour, has just been discovered. A theoretical framework of synchronously rotating planets, in which the risk of a runaway greenhouse on the sunlight…
Centaurus A is one of the closest radio-galaxies to Earth. Its proximity allowed us to extensively study its active galactic nucleus but the core emission mechanism remains elusive because of local strong dust and gas obscuration. The…
A new source in solar corona scattering photospheric and chromospheric Fraunhofer spectral lines is detected below a height of one solar radius above solar limb, consisting of tenuous and cool neutral atoms and much fewer once ionized ions.…
One of the most important objectives of solar physics is the physical understanding of the solar atmosphere, the structure of which is also described in terms of the density (N) and temperature (T) distributions of the atmospheric matter.…
The million degree plasma of the solar corona must be supplied by the underlying layers of the atmosphere. The mechanism and location of energy release, and the precise source of coronal plasma, remain unresolved. In earlier work we pursued…
We use more than a decade of radial velocity measurements for $\alpha$ Cen A, B, and Proxima Centauri from HARPS, CHIRON, and UVES to identify the $M \sin i$ and orbital periods of planets that could have been detected if they existed. At…