Stars: carbon
The GALAH survey: a catalog of carbon enhanced stars and CEMP candidates
... CH stars consists of 41 objects with [Fe/H]< − ...of carbon abundance. Analysing HERMES spectra in order to determine carbon abundance is diffi- cult because the automatic analysis is based on ...
17
Probing the mass loss history of carbon stars using CO line and dust continuum emission
... of carbon stars is ...The stars presented here are not likely to have experienced any drastic long-term mass loss rate modulations, at least less than a factor of ∼ 5, over the past thousands of ...
10
On the production and survival of carbon fuel for superbursts on accreting neutron stars : implications for mass donor evolution
... neutron stars both produce and preserve sufficient amounts of carbon to trigger ...neutron stars found in ...neutron stars with inner crusts that have formed ordered crystal lattices and which ...
13
Photodissociation and chemistry of N 2 in the circumstellar envelope of carbon-rich AGB stars
... AGB stars undergo considerable mass loss and eject dust and molecules into the surrounding regions, creating circumstel- lar envelopes ...new stars may be ...AGB stars is of particular interest and ...
13
Studies of Gas Absorption In Infrared Spectra of Carbon-Rich AGB Stars
... Notice that we assume the gas layer only has one temperature, as we assume LTE. But we know this may not necessarily be the case. So in reality, most likely, the gas layer will have more than one temperature, (or have ...
131
A high dispersion spectral study of one carbon star and two barium stars
... KOIII stars, with some unavoidable flexibility in this classification because of their peculiarities, it was hoped that^CBoo might simulate at least some of the atmospheric conditions in these two barium ...
276
Molecular envelopes around carbon stars. Interferometric observations and models of HCN and CN emission
... smaller than that of CW Leo, which may be explained by the difference in mass loss rates. Lucas et al. (1995) showed that the brightness distribution of SiS ( J = 5 → 4) towards CW Leo is a mixture of a centrally peaked ...
22
The characteristics of cool hydrogen deficient carbon stars
... Vve hope that the observed periods, and radial velocity amplitudes, for these stars will encourage new attempts to model the evolution and pulsations of the cool hydrogen deficient carbo[r] ...
172
Reaction rate for carbon burning in massive stars
... C fusion reaction is an im- portant route for the production of elements with A ≥ 20, and it also influences the later nucleosynthesis processes, such as the slow and rapid neutron-capture processes [3]. In explosive ...
6
The cool hydrogen deficient carbon stars and their atmospheres
... No hydrogen lines may be seen in either the blue or red spectra which is to be expected given the low temperature of M type stars.. It is unlikely that either star is a R CrB or HdC alth[r] ...
184
The pti carbon star angular size survey: effective temperatures and non-sphericity
... these stars must be aspherical, without positing the underlying ...on carbon star mass loss has concentrated on chemistry and dust grain size ...AGB stars, up to v sin i ∼ 7 km s −1 ...
19
The ALMA detection of CO rotational line emission in AGB stars in the Large Magellanic Cloud
... Four carbon (C) stars and two oxygen-rich AGB stars were selected from the sample of about 225 C and 170 M stars studied by Groenewegen & Sloan (in ...AGB stars and red super- ...
11
Laser-plasma and self-absorption measurements with applications to analysis of atomic and molecular stellar astrophysics spectra
... dwarf stars Sirius B and Procyon B, companions to Sirius and Procyon, reveal radiation temperatures of 26 kK and 8 kK, respectively ...molecular, carbon Swan absorption ...
16
Spectrum synthesis of evolved stars
... (§11). In particular, we have performed a curve-of-growth, and spectrum synthesis analysis of the weak-G-band star HD 91805 to obtain an insight into the products of mixing (§1.11); our results are very similar to those ...
210
Ultra-hot stars and their surrounding nebulae
... nitrogen, carbon or oxygen are dominant in the ...(WNE) stars show very weak or no lines of hydrogen in their spectra, strong lines of nitrogen and twice-ionized ...such stars are consistent with CNO ...
308
0e8d288eb0ab73a1786db01a00c97f2257d36a34.pdf
... Sloan et al. ( 2006 ) and Zijlstra et al. ( 2006 ) introduced the Manchester method to extract and compare information uniformly from large samples of infrared spectra from carbon stars. The key metric is ...
19
1711.07803.pdf
... Galactic carbon-rich ...evolved stars in the ...six stars in that sample covering a range of MLRs were fitted with MoD to derive the differences in MLRs, using updated pho- tometry and where ...
26
The evolutionary status of the hot R coronae borealis stars
... Spectroscopically similar to the R CrB stars, the hydrogen-deficient carbon HdC: Warner, 1967 stars· do not have IR excesses Walker, 1986 and are not known to suffer R CrB type minima.. [r] ...
168
Precision diagnostics of pulsation and evolution in helium rich low mass stars
... mass stars linked by their un- usually low hydrogen atmospheric abundance, usually completely replaced with ...sdO) stars are low-mass core helium burning stars with extremely low-mass hydrogen ...
219
Carneiro, Luiz P. (2018): Atmospheric NLTE-models for the spectroscopic analysis of massive stars: new methods and first results for deriving CNO surface abundances. Dissertation, LMU München: Fakultät für Physik
... Inspecting now the “observed” ratios, we see that most of the dwarfs are indeed located at or close to the beginning of the limiting curves, as should be expected (initial phase of their chemical evolution), though the ...
209