Results 31 to 40 of about 54,720 (190)

Using X‐ray computed microtomography (μCT) to determine subsample‐specific cosmogenic noble gas production rates of E (enstatite) chondrites

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 442-463, March 2025.
Abstract Cosmic ray exposure (CRE) ages provide information about the parent bodies and source regions of meteorite classes. Cosmogenic noble gases are often used to quantify exposure time scales ranging from tens of ka to hundreds of Ma. The production rate of cosmogenic noble gases is primarily controlled by a meteorite's chemical composition ...
M. Mijjum, B. J. Andrews, T. J. McCoy, C. M. Corrigan, M. W. Caffee, M. M. Tremblay   +5 more
wiley   +1 more source

On the Formation of Planets in the Milky Way’s Thick Disk

The Astrophysical Journal
Exoplanet demographic surveys have revealed that close-in (≲1 au) small planets orbiting stars in the Milky Way’s thick disk are ∼50% less abundant than those orbiting stars in the Galactic thin disk.
Tim Hallatt, Eve J. Lee
doaj   +1 more source

Self-Sustained Ionization and Vanishing Dead Zones in Protoplanetary Disks [PDF]

Astrophys.J. 628 (2005) L155-L158, 2005
We analyze the ionization state of the magnetohydrodynamically turbulent protoplanetary disks and propose a new mechanism of sustaining ionization. First, we show that in the quasi-steady state of turbulence driven by magnetorotational instability in a typical protoplanetary disk with dust grains, the amount of energy dissipation should be sufficient ...
arxiv   +1 more source

A primitive asteroid that lived fast and died young sampled by a xenolith in the Cold Bokkeveld CM2 carbonaceous chondrite

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 464-483, March 2025.
Abstract Xenoliths in carbonaceous chondrites include lithologies that are unrepresented in the meteorite record and so are a rich source of information on asteroid diversity. Cold Bokkeveld is a CM2 regolith breccia that contains both hydrous and anhydrous lithic clasts. Here, we describe a hydrous clast with a fine‐grained rim.
Martin R. Lee, Cameron J. Floyd, Robin Haller, Sammy Griffin   +3 more
wiley   +1 more source

Disk2Planet: A Robust and Automated Machine Learning Tool for Parameter Inference in Disk–Planet Systems

The Astrophysical Journal
We introduce Disk2Planet, a machine-learning-based tool to infer key parameters in disk–planet systems from observed protoplanetary disk structures. Disk2Planet takes as input the disk structures in the form of 2D density and velocity maps, and outputs ...
Shunyuan Mao, Ruobing Dong, Kwang Moo Yi, Lu Lu, Sifan Wang, Paris Perdikaris   +5 more
doaj   +1 more source

Mid‐infrared detection and characterization of refractory inclusions in CM and CO chondrites: A non‐destructive approach for returned space samples

Meteoritics &Planetary Science, Volume 60, Issue 3, Page 544-569, March 2025.
Abstract Refractory inclusions (RIs) in chondrites are widely used as tracers of early solar system formation conditions. In the context of sample‐return missions, a non‐destructive and non‐invasive analytical tool that can rapidly detect and characterize RIs in space samples during their early phase of study is highly needed.
Jean Charlier, Alice Aléon‐Toppani, Rosario Brunetto, Jérôme Aléon, Ferenc Borondics   +4 more
wiley   +1 more source

A deep search for H2D+ in protoplanetary disks [PDF]

, 2011
The structure in density and temperature of protoplanetary disks surrounding low-mass stars is not yet well known. The protoplanetary disks mid-planes are expected to be very cold and thus depleted in molecules in gas phase, especially CO. Recent observations of molecules at very low apparent temperature (~ 6 K) challenge this current picture of the ...
arxiv   +1 more source

Sites of Planet Formation in Binary Systems. I. Evidence for Disk−Orbit Alignment in the Close Binary FO Tau

The Astronomical Journal
Close binary systems present challenges to planet formation. As binary separations decrease, so do the occurrence rates of protoplanetary disks in young systems and planets in mature systems.
Benjamin M. Tofflemire, Lisa Prato, Adam L. Kraus, Dominique Segura-Cox, G. H. Schaefer, Rachel Akeson, Sean Andrews, Eric L. N. Jensen, Christopher M. Johns-Krull, J. J. Zanazzi, M. Simon   +10 more
doaj   +1 more source

Planet formation in stellar binaries I: planetesimal dynamics in massive protoplanetary disks [PDF]

, 2014
About $20\%$ of exoplanets discovered by radial velocity surveys reside in stellar binaries. To clarify their origin one has to understand the dynamics of planetesimals in protoplanetary disks within binaries. The standard description, accounting for only gas drag and gravity of the companion star has been challenged recently, as the gravity of the ...
arxiv   +1 more source

Petrofabrics in the CM chondrite Kolang: Evidence for non‐spherical chondrules in the protoplanetary disk

Meteoritics &Planetary Science, Volume 60, Issue 2, Page 190-205, February 2025.
Abstract The alignment of non‐spherical “flattened” chondrules into a petrofabric is a common feature of hydrated carbonaceous chondrite meteorites. This texture can form as a result of impacts at peak shock pressures exceeding 10 GPa. However, many carbonaceous chondrites with petrofabrics are unshocked.
Laura E. Jenkins, Martin R. Lee, Luke Daly, Ashley J. King, Cameron J. Floyd, Peter Chung, Sammy Griffin   +6 more
wiley   +1 more source