241 citations · 1.3k across the 23 of their papers we have counts for
23 papers
An extensive grid of DARWIN models for M-type AGB stars II. Effects of pulsation periods on wind properties
Emelie Siderud, Kjell Eriksson, Susanne Höfner +1
Mass loss from asymptotic giant branch (AGB) stars is the result of a complex interplay between pulsation, atmospheric dynamics, dust formation, and radiative acceleration. Pulsati…
Dynamic atmosphere and wind models of C-type asymptotic giant branch stars. Influences of dust optical data on mass loss and observables
Emelie Siderud, Kjell Eriksson, Susanne Höfner +1
Mass loss through stellar winds governs the evolution of stars on the asymptotic giant branch (AGB). In the case of carbon-rich AGB stars, the wind is believed to be driven by radi…
The PLATO Mission
Heike Rauer, Conny Aerts, Juan Cabrera +842
PLATO (PLAnetary Transits and Oscillations of stars) is ESA's M3 mission designed to detect and characterise extrasolar planets and perform asteroseismic monitoring of a large numb…
Carbon star wind models at solar and sub-solar metallicities: a comparative study. I. Mass loss and the properties of dust-driven winds
S. Bladh, K. Eriksson, P. Marigo +2
The atmospheres and winds of C-type AGB stars are modeled with the 1D spherically symmetric radiation-hydrodynamical code DARWIN. To explore the metallicity-dependence of mass loss…
Aperture synthesis imaging of the carbon AGB star R Sculptoris: Detection of a complex structure and a dominating spot on the stellar disk
M. Wittkowski, K. -H. Hofmann, S. Höfner +16
We present near-infrared interferometry of the carbon-rich asymptotic giant branch (AGB) star R Sculptoris. The visibility data indicate a broadly circular resolved stellar disk wi…
Dust-driven winds of AGB stars: The critical interplay of atmospheric shocks and luminosity variations
S. Liljegren, S. Höfner, W. Nowotny +1
Winds of AGB stars are thought to be driven by a combination of pulsation-induced shock waves and radiation pressure on dust. In dynamic atmosphere and wind models, the stellar pul…
Exploring wind-driving dust species in cool luminous giants III. Wind models for M-type AGB stars: dynamic and photometric properties
S. Bladh, S. Höfner, B. Aringer +1
Stellar winds observed in asymptotic giant branch (AGB) stars are usually attributed to a combination of stellar pulsations and radiation pressure on dust. Shock waves triggered by…
The Hamburg/ESO R-process Enhanced Star survey (HERES) X. HE 2252-4225, one more r-process enhanced and actinide-boost halo star
L. Mashonkina, N. Christlieb, K. Eriksson
We report on a detailed abundance analysis of the r-process enhanced giant star, HE 2252-4225 ([Fe/H] = -2.63, [r/Fe] = 0.80). Determination of stellar parameters and element abund…
The Chemical Evolution of Fluorine in the Bulge - High-resolution K-band spectra of giants in three fields
H. Jönsson, N. Ryde, G. M. Harper +6
Possible main formation sites of F in the Universe include AGB stars, the ν-process in Type II SNe, and/or W-R stars. The importance of the W-R stars has theoretically been questio…
Exploring wind-driving dust species in cool luminous giants II. Constraints from photometry of M-type AGB stars
Sara Bladh, Susanne Höfner, Walter Nowotny +1
The heavy mass loss observed in evolved asymptotic giant branch (AGB) stars is usually attributed to a two-stage process: atmospheric levitation by pulsation-induced shock waves, f…
Synthetic photometry for carbon-rich giants. III. Tracing the sequence of mass-losing galactic C-type Miras
W. Nowotny, B. Aringer, S. Hoefner +1
With the help of model calculations we aim at reproducing the observational photometric findings for a large sample of well-characterised galactic C-type Mira variables losing mass…
Comparative Modelling of the Spectra of Cool Giants
T. Lebzelter, U. Heiter, C. Abia +24
Our ability to extract information from the spectra of stars depends on reliable models of stellar atmospheres and appropriate techniques for spectral synthesis. Various model code…
Analysis of old very metal rich stars in the solar neighbourhood
M. Trevisan, B. Barbuy, K. Eriksson +3
A sample of mostly old metal-rich dwarf and turn-off stars with high eccentricity and low maximum height above the Galactic plane has been identified. From their kinematics, it was…
Sulphur abundances in halo giants from the [S I] line at 1082 nm and the S I triplet around 1045 nm
H. Jönsson, N. Ryde, P. E. Nissen +4
It is still debated whether or not the Galactic chemical evolution of sulphur in the halo followed the constant or flat trend with [Fe/H], ascribed to the result of explosive nucle…
An abundance study of red-giant-branch stars in the Hercules dwarf spheroidal galaxy
D. Adén, K. Eriksson, S. Feltzing +3
Using high-resolution spectroscopy, we provide a determination of [Fe/H] and [Ca/H] for confirmed red-giant branch member stars of the Hercules dwarf spheroidal galaxy. Based on th…
Fluorine Abundances in Galactic AGB Stars
C. Abia, K. Cunha, S. Cristallo. +10
An analysis of the fluorine abundance in Galactic AGB carbon stars (24 N-type, 5 SC-type and 5 J-type) is presented. This study uses the state- of-the-art carbon rich atmosphere mo…
The detached dust and gas shells around the carbon star U Ant
M. Maercker, H. Olofsson, K. Eriksson +2
Context: Geometrically thin, detached shells of gas have been found around a handful of carbon stars. --Aims: Previous observations of scattered stellar light in the circumstellar…
Evidence of enrichment by individual supernova from elemental abundance ratios in the very metal-poor dSph galaxy Bootes I
S. Feltzing, K. Eriksson, J. Kleyna +1
Aim: We establish the mean metallicity from high-resolution spectroscopy for the recently found dwarf spheroidal galaxy Bootes I and test whether it is a common feature for ultra-f…
CNO abundances of HdC and RCB stars: a view of the nucleosynthesis in a white dwarf merger
D. A. Garcia-Hernandez, K. H. Hinkle, David. L. Lambert +1
We present high-resolution (R~50,000) observations of near-IR transitions of CO and CN of the five known hydrogen-deficient carbon (HdC) stars and four R Coronae Borealis (RCB) sta…
Intense Mass Loss from C-rich AGB Stars at low Metallicity?
L. Mattsson, R. Wahlin, S. Höfner +1
We argue that the energy injection of pulsations may be of greater importance to the mass-loss rate of AGB stars than metallicity, and that the mass-loss trend with metallicity is…
HE 0557-4840 - Ultra-Metal-Poor and Carbon-Rich
John E. Norris, N. Christlieb, A. J. Korn +5
We report the discovery and high-resolution, high S/N, spectroscopic analysis of the ultra-metal-poor red giant HE 0557-4840, which is the third most heavy-element deficient star c…
HE1327-2326, an unevolved star with [Fe/H]<-5.0. I. A Comprehensive Abundance Analysis
W. Aoki, A. Frebel, N. Christlieb +17
We present the elemental abundances of HE1327-2326, the most iron-deficient star known, determined from a comprehensive analysis of spectra obtained with the Subaru Telescope High…
Imaging of detached shells around the carbon stars R Scl and U Ant through scattered stellar light
D. Gonzalez Delgado, H. Olofsson, H. E. Schwarz +2
We present the first optical images of scattered light from large, detached gas/dust shells around two carbon stars, R Scl and U Ant, obtained in narrow band filters centred on the…