Search Publications
Two new nova shells associated with V4362 Sagittarii and DO Aquilae
Boumis, P.; Derlopa, S.; Akras, S. +8 more
A classical nova is an eruption on the surface of a white dwarf in an accreting binary system. The material ejected from the white dwarf surface generally forms an axisymmetric shell. The shaping mechanisms of nova shells are probes of the processes that take place at energy scales between planetary nebulae and supernova remnants. We report on the…
Optical Transmission Spectra of Hot Jupiters: Effects of Scattering
Tinetti, Giovanna; Sengupta, Sujan; Chakrabarty, Aritra
We present new grids of transmission spectra for hot Jupiters by solving the multiple-scattering radiative transfer equations with non-zero scattering albedo instead of using the Beer-Bouguer-Lambert law for the change in the transmitted stellar intensity. The diffused reflection and transmission due to scattering increase the transmitted stellar …
Stellar wind models of central stars of planetary nebulae
Krtička, J.; Kubát, J.; Krtičková, I.
Context. Fast line-driven stellar winds play an important role in the evolution of planetary nebulae, even though they are relatively weak.
Aims: We provide global (unified) hot star wind models of central stars of planetary nebulae. The models predict wind structure including the mass-loss rates, terminal velocities, and emergent fluxes from…
First L band detection of hot exozodiacal dust with VLTI/MATISSE
Kirchschlager, Florian; Ertel, Steve; Matter, Alexis +2 more
For the first time, we observed the emission of hot exozodiacal dust in L band. We used the new instrument MATISSE at the Very Large Telescope Interferometer to detect the hot dust around κ Tuc with a significance of 3σ to 6σ at wavelengths between 3.37 and $3.85\, {\mu {\rm m}}$ and a dust-to-star flux ratio of 5 to $7{{{\ \rm per\ cent}}}$ . We …
First discovery of trans-iron elements in a DAO-type white dwarf (BD-22°3467)
Rauch, T.; Werner, K.; Kruk, J. W. +4 more
We have identified 484 lines of the trans-iron elements (TIEs) Zn, Ga, Ge, Se, Br, Kr, Sr, Zr, Mo, In, Te, I, Xe, and Ba, for the first time in the ultraviolet spectrum of a DAO-type WD, namely BD-22°3467, surrounded by the ionized nebula Abell 35. Our TIE abundance determination shows extremely high overabundances of up to five dex - a…
Colour-magnitude diagrams of transiting exoplanets - III. A public code, nine strange planets, and the role of phosphine
Triaud, Amaury H. M. J.; Dransfield, Georgina
Colour-magnitude diagrams provide a convenient way of comparing populations of similar objects. When well populated with precise measurements, they allow quick inferences to be made about the bulk properties of an astronomic object simply from its proximity on a diagram to other objects. We present here a PYTHON toolkit that allows a user to produ…
Distance scale for high-luminosity stars in OB associations and in field with Gaia DR2. Spurious systematic motions
Melnik, A. M.; Dambis, A. K.
We calculated the median parallaxes for 47 OB associations including at least 10 stars with known Gaia DR2 parallaxes. A comparison between trigonometric and photometric parallaxes of OB associations reveals a zero-point offset of
Style and intensity of hydration among C-complex asteroids: A comparison to desiccated carbonaceous chondrites
Vernazza, P.; Usui, F.; Schmitt, B. +3 more
Here we report a comparison between reflectance spectroscopy of meteorites under asteroidal environment (high vacuum and temperature) and Main Belt and Near Earth Asteroids spectra. Focusing on the -OH absorption feature around 3 µm, we show that the asteroidal environment induces a reduction of depth and width of the band, as well as a shif…
Powerful ionized gas outflows in the interacting radio galaxy 4C+29.30
Storchi-Bergmann, Thaisa; Riffel, Rogemar A.; Couto, Guilherme S. +2 more
We investigate the ionized gas excitation and kinematics in the inner $4.3\, \times \, 6.2$ kpc2 of the merger radio galaxy 4C+29.30. Using optical integral field spectroscopy with the Gemini North Telescope, we present flux distributions, line-ratio maps, peak velocities and velocity dispersion maps as well as channel maps with a spati…
A Photoionized Accretion Disk around a Young High-mass Star
Sanhueza, Patricio; Garay, Guido; Guzmán, Andrés E. +2 more
We present high spatial resolution (52 au) observations of the high-mass young stellar object (HMYSO) G345.4938+01.4677 made using the Atacama Large Millimeter/submillimeter Array. This O-type HMYSO is located at 2.38 kpc and is associated with a luminosity of 1.5 × 105 L⊙. We detect circumstellar emission from the H38β hydro…