Results 121 to 130 of about 411,596 (264)

A 40 Myr OLD GASEOUS CIRCUMSTELLAR DISK AT 49 CETI: MASSIVE CO-RICH COMET CLOUDS AT YOUNG A-TYPE STARS [PDF]

open access: yes, 2012
The gaseous molecular disk that orbits the main-sequence A-type star 49 Ceti has been known since 1995, but the stellar age and the origin of the observed carbon monoxide molecules have been unknown.
B. Zuckerman, I. Song
semanticscholar   +1 more source

L1448 IRS3B: Dust Polarization Aligned with Spiral Features, Tracing Gas Flows

open access: yesThe Astrophysical Journal
Circumstellar disk dust polarization in the (sub)millimeter is, for the most part, not from dust grain alignment with magnetic fields but rather indicative of a combination of dust self-scattering with a yet unknown alignment mechanism that is consistent
Leslie W. Looney   +13 more
doaj   +1 more source

Exocomets in the circumstellar gas disk of HD 172555 [PDF]

open access: yes, 2014
The source HD 172555 is a young A7V star surrounded by a debris disk with a gaseous component. Here, we present the detection of variable absorption features detected simultaneously in the Ca II K and H doublet lines (at λ3933 A and λ3968 A).
F. Kiefer   +5 more
semanticscholar   +1 more source

Modeling Circumstellar Gas Emission around a White Dwarf Using cloudy

open access: yesThe Astronomical Journal
The chemical composition of an extrasolar planet is fundamental to its formation, evolution, and habitability. In this study, we explore a new way to measure the chemical composition of the building blocks of extrasolar planets by measuring the gas ...
Siyi Xu   +11 more
doaj   +1 more source

Tracing large-scale structures in circumstellar disks with ALMA

open access: yes, 2012
Planets are supposed to form in circumstellar disks. The gravitational potential of a planet perturbs the disk and leads to characteristic structures, i.e. spiral waves and gaps, in the disk's density profile.
Klahr, Hubert H.   +3 more
core   +1 more source

VLTI/GRAVITY Provides Evidence the Young, Substellar Companion HD 136164 Ab Formed Like a “Failed Star”

open access: yesThe Astronomical Journal
Young, low-mass brown dwarfs orbiting early-type stars, with low mass ratios ( q ≲ 0.01), appear to be intrinsically rare and present a formation dilemma: could a handful of these objects be the highest-mass outcomes of “planetary” formation channels ...
William O. Balmer   +96 more
doaj   +1 more source

Sites of Planet Formation in Binary Systems. II. Double the Disks in DF Tau

open access: yesThe Astronomical Journal
This article presents the latest results of our Atacama Large Millimeter/submillimeter Array (ALMA) program to study circumstellar disk characteristics as a function of orbital and stellar properties in a sample of young binary star systems known to host
Taylor Kutra   +10 more
doaj   +1 more source

Dynamics of Circumstellar Disks III: The case of GG Tau A

open access: yes, 2016
(abridged) We present 2-dimensional hydrodynamic simulations using the Smoothed Particle Hydrodynamic (SPH) code, VINE, to model a self-gravitating binary system similar to the GG Tau A system.
Marzari, F., Nelson, Andrew F.
core   +1 more source

The Disks In Scorpius–Centaurus Survey (DISCS). I. Four Newly Resolved Debris Disks in Polarized Intensity Light

open access: yesThe Astronomical Journal
The presence of infrared excesses around stars directly correlates with spatially resolved imaging detections of circumstellar disks at both millimeter and optical/near-infrared wavelengths.
Justin Hom   +10 more
doaj   +1 more source

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