Results 51 to 60 of about 772 (182)

Insights Into the Gas‐Phase Structure and Internal Dynamics of Diphenylsilane: A Broadband Rotational Spectroscopy Study

open access: yesChemPhysChem, Volume 26, Issue 2, January 14, 2025.
The structure of diphenylsilane could be determined from the rotational spectra of all its singly substituted heavy atom isotopologues. A comparison with its oxygen analogue diphenylether revealed some interesting differences in the internal dynamics as well as in the gas‐phase structure.
Gayatri Batra, Melanie Schnell
wiley   +1 more source

First direct detection of large polycyclic aromatic hydrocarbons on asteroid (162173) Ryugu samples: An interstellar heritage

open access: yesNatural Sciences, Volume 4, Issue 4, October 2024.
Large free aromatic species, with up to 61 carbon atoms, were detected in grains of the Ryugu carbonaceous asteroid using ultra‐sensitive two‐step laser mass spectrometry. This discovery confirms the presence of large polycyclic aromatic hydrocarbons in the interstellar medium and provides new information on the formation and evolution of organic ...
Hassan Sabbah   +3 more
wiley   +1 more source

Early Planet Formation in Embedded Disks (eDisk). XIII. Aligned Disks with Nonsettled Dust around the Newly Resolved Class 0 Protobinary R CrA IRAS 32

open access: yesThe Astrophysical Journal
Young protostellar binary systems, with expected ages less than ∼10 ^5 yr, are little modified since birth, providing key clues to binary formation and evolution. We present a first look at the young, Class 0 binary protostellar system R CrA IRAS 32 from
Frankie J. Encalada   +21 more
doaj   +1 more source

Electron microscopy observations of the diversity of Ryugu organic matter and its relationship to minerals at the micro‐ to nano‐scale

open access: yesMeteoritics &Planetary Science, Volume 59, Issue 8, Page 2023-2043, August 2024.
Abstract Transmission electron microscopy analyses of Hayabusa2 samples show that Ryugu organic matter exhibits a range of morphologies, elemental compositions, and carbon functional chemistries consistent with those of carbonaceous chondrites that have experienced low‐temperature aqueous alteration.
Rhonda M. Stroud   +112 more
wiley   +1 more source

The Role of Dust in Circumstellar Chemistry [PDF]

open access: yesSymposium - International Astronomical Union, 1987
The outer envelopes of the outflows from late-type stars where the dust and molecules have already been formed and the matter has been accelerated to its terminal velocity are the focus of this review. One major role for grains in the circumstellar chemistry is the protection of molecules against photodissociation by ambient interstellar ultraviolet ...
openaire   +1 more source

DUST DISTRIBUTION IN THE β PICTORIS CIRCUMSTELLAR DISKS [PDF]

open access: yesThe Astrophysical Journal, 2009
We present 3-D models of dust distribution around beta Pictoris that produce the best fits to the Hubble Space Telescope Advanced Camera for Surveys' (HST/ACS) images obtained by Golimowski and co-workers. We allow for the presence of either one or two separate axisymmetric dust disks.
Ahmic, Mirza   +2 more
openaire   +2 more sources

High-velocity Circumstellar Gas Orbiting a White Dwarf Star

open access: yesThe Astrophysical Journal
Numerous white dwarf stars are known to be orbited by disks of gas and dust. To date, broad, ∼300 km s ^−1 wide, gaseous circumstellar absorption features have only been reported for the already iconic WD 1145+017, where one is witnessing the breakup of ...
B. Zuckerman   +8 more
doaj   +1 more source

JWST imaging of the closest globular clusters—I. Possible infrared excess among white dwarfs in NGC 6397

open access: yesAstronomische Nachrichten, Volume 345, Issue 6-7, July-August 2024.
Abstract We present James Webb Space Telescope observations of the globular cluster NGC 6397 and use them to extend to infrared wavelengths the characterization of the cluster's entire white dwarf (WD) cooling sequence (CS). The data allows us to probe fundamental astrophysical WD properties and to search for evidence in their colors for (or against ...
L. R. Bedin   +11 more
wiley   +1 more source

The Type II SN 2025pht in NGC 1637: A Red Supergiant with Carbon-rich Circumstellar Dust as the First JWST Detection of a Supernova Progenitor Star

open access: yesThe Astrophysical Journal Letters
We present follow-up imaging and spectroscopy and pre-explosion imaging of SN 2025pht located in NGC 1637 at 12 Mpc. Our spectroscopy shows that SN 2025pht is a Type II supernova (SN) with broad lines of hydrogen and with minimal line-of-sight extinction
Charles D. Kilpatrick   +9 more
doaj   +1 more source

Hidden metallic iron in amorphous silicate dust?

open access: yesAstronomy & Astrophysics
Context. Amorphous silicate dust is a major component in the interstellar and circumstellar dust formed in the outflow of asymptotic giant branch (AGB) stars.
Enomoto H.   +3 more
doaj   +1 more source

Home - About - Disclaimer - Privacy