Results 51 to 60 of about 586 (186)

Chemical Models of Circumstellar Disks [PDF]

open access: yesSymposium - International Astronomical Union, 2000
We investigate the evolution of molecular abundances in circumstellar disks around young stars via numerical simulations. The results are compared with the composition of comets and radio observations of protoplanetary disks. First, we consider the molecular evolution in the midplane of the disk.
Yuri Aikawa, Eric Herbst
openaire   +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

Projection of circumstellar disks on their environments [PDF]

open access: yesAstronomy & Astrophysics, 2005
16 pages, 12 figures, accepted for publication in Astronomy & ...
Pontoppidan, K.M., Dullemond, C.P.
openaire   +4 more sources

Probing the Era of Giant Collisions: Millimeter Observations of the HD 166191 System

open access: yesThe Astrophysical Journal
We present nonsimultaneous Atacama Large Millimeter/submillimeter Array (ALMA) Band 7 and Submillimeter Array (SMA) observations of the HD 166191 disk, which was recently thought to have a collision in its terrestrial planet zone.
Kadin Worthen   +7 more
doaj   +1 more source

Circumstellar Disks

open access: yes, 1999
33 pages, 12 figures, to be published in The Physics of Star Formation and Early Evolution II, C.J. Lada and N.D.
openaire   +2 more sources

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

Secret of Longevity: Protoplanetary Disks as a Source of Gas in Debris Disks

open access: yesThe Astrophysical Journal
While protoplanetary disks (PPDs) are generally thought to disperse within several million years, recent observations have revealed gas in their older counterparts, debris disks.
Wataru Ooyama   +4 more
doaj   +1 more source

Takeout and Delivery: Erasing the Dusty Signature of Late-stage Terrestrial Planet Formation

open access: yesThe Astrophysical Journal, 2023
The formation of planets like Earth is expected to conclude with a series of late-stage giant impacts that generate warm dusty debris, the most anticipated visible signpost of terrestrial planet formation in progress.
Joan R. Najita, Scott J. Kenyon
doaj   +1 more source

The deep eclipses of RW Aur revisited by long‐term photometric and spectroscopic monitoring

open access: yesAstronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract RW Aurigae is a young stellar system containing a classical T Tauri star as the primary component. It shows deep, irregular dimmings, first detected in 2010. At the University Observatory Jena, we carried out optical follow‐up observations. We performed multiband (BVRI) photometry of the system with the Cassegrain‐Teleskop‐Kamera II and the ...
Oliver Lux   +2 more
wiley   +1 more source

Limitations of the modified blackbody fit method for determining molecular cloud properties

open access: yesAstronomische Nachrichten, Volume 345, Issue 4, May 2024.
Abstract Achieving a comprehensive understanding of the star and planet formation process is one of the fundamental tasks of astrophysics, requiring detailed knowledge of the physical conditions during the different phases of this process. During the earliest stages, that is, concerning physical processes in molecular clouds and filaments, the column ...
Niko Zielinski, Sebastian Wolf
wiley   +1 more source

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