Results 111 to 120 of about 3,177 (205)

Observations of the circumstellar gas shells around Betelgeuse and Antares

open access: yesThe Astrophysical Journal, 1975
Results are presented on the direct observations of the circumstellar shell around alpha-Ori, along with new observations of the Ca II infrared triplet lines which provide lower limits for the Ca(+) shell radii for alpha-Ori and alpha-Sco (Antares). The 8542-A line in alpha-Ori does not show a circumstellar absorption core, and the shell radius limit ...
A. P. Bernat, D. L. Lambert
openaire   +1 more source

Spectroscopic Identification and Photochemistry of Astrochemically Relevant Phosphorus-bearing Molecules [O, C, N, P] and [2O, C, N, P]

open access: yesThe Astrophysical Journal
Diatomic molecules phosphorus monoxide (PO) and phosphorus mononitride (PN) are the main reservoirs of gas-phase phosphorus in interstellar and circumstellar environments, indicating the possibility of forming new phosphorus-bearing molecules through ...
Bifeng Zhu   +8 more
doaj   +1 more source

Ring-gap Structures in the Class I Circumstellar Disk of CrA IRS 2 Associated with the Magnetic Flux-driven Bubble

open access: yesThe Astrophysical Journal
Recent Atacama Large Millimeter/submillimeter Array (ALMA) observations with 0 $\mathop{.}\limits^{^{\prime\prime} }$ 1 resolution have revealed characteristic substructures in circumstellar disks around young Class I sources, providing clues to the ...
Ayumu Shoshi   +6 more
doaj   +1 more source

87th Annual Meeting of the Meteoritical Society 2025: Abstracts

open access: yes
Meteoritics &Planetary Science, Volume 60, Issue S1, Page 30-350, August 2025.
wiley   +1 more source

OH-IR stars. I. Physical properties of circumstellar envelopes [PDF]

open access: yes, 1976
A theoretical model of the circumstellar envelope which surrounds a OH-IR star is developed. The circumstellar gas is ejected by radiation pressure which acts on dust grains that condense in the atmosphere of the central star.
Scoville, Nick, Goldreich, Peter
core  

Accretion and Outflow in Orion-KL Source I

open access: yesThe Astrophysical Journal
We present Atacama Large Millimeter/submillimeter Array observations of SiO, SiS, H _2 O, NaCl, and SO line emission at ∼30–50 mas resolution. These images map the molecular outflow and disk of Orion Source I (SrcI) on ∼12–20 au scales.
Melvyn Wright   +8 more
doaj   +1 more source

Observing CO in Circumstellar Disks [PDF]

open access: yes, 2010
This dissertation includes high-resolution, near-infrared spectroscopy to study CO in circumstellar disks around Herbig Ae/Be stars. The velocity-resolved spectra was used to measure the distribution of gas in the circumstellar disk and thus determine ...
Troutman, Matthew
core   +1 more source

Multiband ALMA Polarization Observations of BHB 07-11 Reveal Aligned Dust Grains in Complex Spiral Arm Structures

open access: yesThe Astrophysical Journal
Polarization-mode observations from the Atacama Large Millimeter/submillimeter Array (ALMA) are powerful tools for studying the dust grain populations in circumstellar disks.
Austen Fourkas   +10 more
doaj   +1 more source

Detection of CH in the O-rich Planetary Nebula NGC 6302

open access: yesThe Astrophysical Journal
Planetary nebulae are sites where ejected stellar material evolves into complex molecules, but the precise physical conditions and chemical routes that govern these processes are unclear.
Charmi Bhatt   +35 more
doaj   +1 more source

Kinematics of the circumstellar gas around UXOR stars

open access: yes, 2004
This thesis presents the results of a high spectral resolution study of the circumstellar (CS) gas around the intermediate mass, pre-main sequence UXOR stars BF Ori, SV Cep, UX Ori, WW Vul and XY Per. The results are based on a set of 38 echelle spectra covering the spectral range 3800-5900 Angstroms, monitoring the stars on time scales of months, days
openaire   +2 more sources

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