Results 21 to 30 of about 3,156,581 (329)
A Dramatic Decrease in Carbon Star Formation in M31 [PDF]
Astrophysical Journal, 2019 We analyze resolved stellar near-infrared photometry of 21 Hubble Space Telescope (HST) fields in M31 to constrain the impact of metallicity on the formation of carbon stars. Observations of nearby galaxies show that carbon stars are increasingly rare at
M. Boyer +10 more
semanticscholar +1 more source
Carbon star wind models at solar and sub-solar metallicities: a comparative study [PDF]
Astronomy & Astrophysics, 2019 Context. The heavy mass loss observed in evolved stars on the asymptotic giant branch (AGB) is usually attributed to dust-driven winds, but it is still an open question how much AGB stars contribute to the dust production in the interstellar medium ...
S. Bladh +4 more
semanticscholar +1 more source
Carbon-bearing Molecules in a Possible Hycean Atmosphere [PDF]
Astrophysical Journal Letters, 2023 The search for habitable environments and biomarkers in exoplanetary atmospheres is the holy grail of exoplanet science. The detection of atmospheric signatures of habitable Earth-like exoplanets is challenging owing to their small planet–star size ...
N. Madhusudhan +5 more
semanticscholar +1 more source
A rich hydrocarbon chemistry and high C to O ratio in the inner disk around a very low-mass star [PDF]
Nature Astronomy, 2023 Highly abundant hydrocarbons in a very low-mass star’s disk are detected using the JWST. This unique chemical composition is probably due to the destruction of carbon grains, and the resulting high gaseous C/O ratio may have a profound impact on the ...
B. Tabone +45 more
semanticscholar +1 more source
The Puzzling Properties of the MACS1149-JD1 Galaxy at z = 9.11
The Astrophysical Journal Letters, 2023 We analyze new JWST NIRCam and NIRSpec data on the redshift 9.11 galaxy MACS1149-JD1 (hereafter JD1). Our NIRCam imaging data reveal that JD1 comprises three spatially distinct components. Our spectroscopic data indicate that JD1 appears dust free but is
Massimo Stiavelli +8 more
doaj +1 more source
No thick carbon dioxide atmosphere on the rocky exoplanet TRAPPIST-1 c [PDF]
Nature, 2023 Seven rocky planets orbit the nearby dwarf star TRAPPIST-1, providing a unique opportunity to search for atmospheres on small planets outside the Solar System^ 1 . Thanks to the recent launch of the James Webb Space Telescope (JWST), possible atmospheric
Sebastian Zieba +18 more
semanticscholar +1 more source
HIGH-SPEED BULLET EJECTIONS DURING THE AGB-TO-PLANETARY NEBULA TRANSITION: HST OBSERVATIONS OF THE CARBON STAR, V HYDRAE [PDF]
, 2016 The well-studied carbon star, V Hya, showing evidence for high-speed, collimated outflows and dense equatorial structures, is a key object in the study of the poorly understood transition of AGB stars into aspherical planetary nebulae.
R. Sahai, S. Scibelli, M. Morris
semanticscholar +1 more source
Population Synthesis of Helium White Dwarf–Red Giant Star Mergers and the Formation of Lithium-rich Giants and Carbon Stars [PDF]
Astrophysical Journal, 2020 The formation histories of lithium-rich and carbon-rich red giants are not yet understood. It has been proposed that the merger of a helium-core white dwarf with a red giant branch (RGB) star might provide a solution. We have computed an extended grid of
Xianfei Zhang +3 more
semanticscholar +1 more source
The Binary Dwarf Carbon Star SDSS J125017.90+252427.6 [PDF]
, 2018 Although dwarf carbon (dC) stars are universally thought to be binaries in order to explain the presence of C2 in their spectra while still near main-sequence luminosity, direct observational evidence for their binarity is remarkably scarce.
B. Margon +5 more
semanticscholar +1 more source
Mathematics, 2023 Under the global consensus of carbon peaking and carbon neutrality, new energy vehicles have gradually become mainstream, driven by the dual crises regarding the atmospheric environment and energy security.
Sumin Yu +3 more
doaj +1 more source