Results 41 to 50 of about 55,649 (206)

The formation radius of HCN in O-rich asymptotic giant branch stars

open access: yesAstronomy & Astrophysics
Context. Molecules detected in circumstellar envelopes around asymptotic giant branch (AGB) stars are generally well explained in terms of formation under chemical equilibrium in the stellar atmosphere or photochemistry in the outer expanding layers ...
Marinho L.   +5 more
doaj   +1 more source

Characterizing circumstellar disk around young stars [PDF]

open access: yes, 2010
The circumstellar disks play a fundamental role in star and planet formation process. Studies on circumstellar disks are generally carried on following two viable approaches: "statistical" studies, where a large samples of sources are measured to ...
Schisano, Eugenio
core   +1 more source

SPECTROSCOPIC MONITORING OF THE B[E] OBJECTS FSCMA AND MOCAM

open access: yesOdessa Astronomical Publications, 2019
Objects with the B[e] phenomenon exhibit permitted and forbidden emission lines due to the presence of circumstellar ionized gas and large infrared excesses due to processing of the stellar radiation by circumstellar dust.
A. K. Kuratova   +10 more
doaj   +1 more source

Photoelectron Spectroscopy of the Phosphorus Monosulfide (PS) and Phosphorus Monoxide (PO) Radicals

open access: yesSmall Structures, Volume 7, Issue 1, January 2026.
Sketch of the experiment to measure the photo electron spectrum of the PS radical produced in situ with a mixture of PH3, H2S and F atoms. PO and PS radicals are the smallest units of phosphorus oxides and phosphorus sulfides, respectively, two rich families of refractory compounds widely employed in industrial and technological applications. These two
Pedro Recio   +10 more
wiley   +1 more source

Circumstellar envelopes as seen with millimeter interferometers

open access: yes, 2006
I present a survey of recent discoveries concerning circumstellar envelopes around evolved stars: asymptotic giant branch stars and (proto-) planetary nebulae, and radiative techniques used to infer their ...
E. Josselin
core   +1 more source

Equatorial Enhancement in the Dustiest OH/IR Stars in the Galactic Bulge

open access: yesThe Astrophysical Journal
We have detected the 10 μ m silicate feature and the 11.3 μ m crystalline forsterite feature in absorption in 21 oxygen-rich asymptotic giant branch stars in the Galactic bulge.
Steven R. Goldman   +4 more
doaj   +1 more source

Recent Progress in Finding Binary Systems with the B[e] Phenomenon

open access: yesGalaxies, 2023
This paper describes recent studies of the FS CMa-type objects, a group of stars showing the B[e] phenomenon defined in 2007. The objects exhibit strong emission-line spectra with both permitted and forbidden lines suggesting the presence of a B-type ...
Anatoly S. Miroshnichenko   +11 more
doaj   +1 more source

Satellites and Small Bodies With ALMA: Insights Into Solar System Formation and Evolution

open access: yesAGU Advances, Volume 6, Issue 6, December 2025.
Abstract Our understanding of the formation and evolution of planetary systems has made major advances in the past decade. This progress has been driven in large part by the Atacama Large Millimeter/submillimeter Array (ALMA), which has given us an unprecedented view of solar system bodies themselves, and of the structure and chemistry of forming ...
Katherine de Kleer   +3 more
wiley   +1 more source

Energy Balance in Circumstellar Envelopes [PDF]

open access: yesInternational Astronomical Union Colloquium, 2000
AbstractWe have successfully determined the kinetic temperature of the electron gas as a function of position in the circumstellar envelopes of Be stars. Our method yields a self-consistent solution of the equation for energy conservation, thus eliminating the necessity to assume arbitrarily a temperature for the gas.
C. E. Millar   +2 more
openaire   +1 more source

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

open access: yesAstronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin   +10 more
wiley   +1 more source

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