相关论文: The Brightest Carbon Stars

We present ground-based 3 micron spectra of obscured Asymptotic Giant Branch (AGB) stars in the Magellanic Clouds (MCs). We identify the carbon stars on the basis of the 3.1 micron absorption by HCN and C2H2 molecules. We show evidence for…

We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and…

We calculated theoretical evolutionary sequences of asymptotic giant branch (AGB) stars, including formation and evolution of dust grains in their circumstellar envelope. By considering stellar populations of the Large Magellanic Cloud…

We present N-band photometry for a sample of 21 dust- enshrouded AGB stars in the Large Magellanic Cloud, and three additional sources in the Small Magellanic Cloud. Together with near-IR photometry, this is used to give a tentative…

We trace the full evolution of low- and intermediate-mass stars ($1 M_{\odot} \leq M \leq 8M_{\odot}$) during the Asymptotic Giant Branch (AGB) phase in the {\it Spitzer} two-color and color-magnitude diagrams. We follow the formation and…

The stars in the Magellanic Clouds with the largest degree of obscuration are used to probe the highly uncertain physics of stars in the asymptotic giant branch (AGB) phase of evolution. Carbon stars in particular, provide key information…

Stars of intermediate mass (~4-8Msun) evolve to the stage of white dwarfs through the asymptotic giant branch (AGB) stage: stationary hydrogen shell burning and helium thermal pulses, wind mass loss and planetary nebula ejection. Almost the…

In 1981, the idea of a superwind that ends the life of cool giant stars was proposed. Extreme OH/IR-stars develop superwinds with the highest mass-loss rates known so far, up to a few 10^(-4) Msun/yr, informing our understanding of the…

We compare theoretical dust yields for stars with mass 1 Msun < mstar < 8 Msun, and metallicities 0.001 < Z < 0.008 with observed dust production rates (DPR) by carbon- rich and oxygen-rich Asymptotic Giant Branch (C-AGB and O-AGB) stars in…

We present high-resolution (R~60,000) optical spectra of a carefully selected sample of heavily obscured and presumably massive O-rich Asymptotic Giant Branch (AGB) stars in the Magellanic Clouds (MCs). We report the discovery of strong Rb…

We present dust yields for asymptotic giant branch (AGB) and super--asymptotic giant branch (SAGB) stars of solar metallicity. Stars with initial mass $1.5~M_{\odot} \leq M_{\rm ini} \leq 3~M_{\odot}$ reach the carbon star stage during the…

We have carried out an infrared search for obscured AGB stars in the Magellanic Clouds. The survey uncovered a number of obscured AGB stars as well as some supergiants with infrared excess. We present photometry of the sources and discuss…

The luminosities and periods of obscured AGB stars in the LMC are discussed using a combination of ISO and ground-based infrared photometry. The bolometric luminosities of these stars fall close to an extrapolation of the period-luminosity…

There are strong observational indications that the dense slow winds of cool luminous AGB stars are driven by radiative pressure on dust grains which form in the extended atmospheres resulting from pulsation-induced shocks. For carbon…

We present new models for the evolution of stars with mass in the range 1Msun < M < 7.5Msun, followed from the pre-main-sequence through the asymptotic giant branch phase. The metallicity adopted is $Z=3*10^{-4} (which, with an…

Intermediate mass stars (1-8 solar masses) evolve along the Asymptotic Giant Branch after completion of hydrogen and helium core burning. At the tip they lose for several ten to hundred thousand years copious amounts of mass and exhibit…

Blue horizontal branch and UV bright stars in several globular clusters are analysed spectroscopically and the results are compared with predictions of stellar evolutionary theory. We find that the distribution of temperatures and surface…

We analyze resolved stellar near-infrared photometry of 21 HST fields in M31 to constrain the impact of metallicity on the formation of carbon stars. Observations of nearby galaxies show that the carbon stars are increasingly rare at higher…

As part of a reanalysis of galactic Asymptotic Giant Branch (AGB) stars at infrared (IR) wavelengths, we discuss a sample (357) of carbon stars for which mass loss rates, near-IR photometry and distance estimates exist. For 252 sources we…

We used models of thermally-pulsing asymptotic giant branch (AGB) stars, that also describe the dust-formation process in the wind, to interpret the combination of near- and mid-infrared photometric data of the dwarf galaxy IC 1613. This is…