Results 51 to 60 of about 18,502 (219)

Conditions for Gravitational Instability in Protoplanetary Disks

, 2012
Gravitational instability is one of considerable mechanisms to explain the formation of giant planets. We study the gravitational stability for the protoplanetary disks around a protostar.
Kimura, Shigeo S., Tsuribe, Toru
core   +1 more source

Young "Dipper" Stars in Upper Sco and $\rho$ Oph Observed by K2 [PDF]

, 2015
We present ten young ($\lesssim$10 Myr) late-K and M dwarf stars observed in K2 Campaign 2 that host protoplanetary disks and exhibit quasi-periodic or aperiodic dimming events.
Ansdell, M., Boyajian, T. S., Gaidos, E., Jacobs, T. L., Jek, K. J., Kennedy, G., LaCourse, D. M., Mann, A. W., Rappaport, S. A., Williams, J. P., Wyatt, M. C.   +10 more
core   +4 more sources

Ryugu reference project: Recommendations from the measurement definition team

Meteoritics &Planetary Science, Volume 61, Issue 5, Page 819-848, May 2026.
Abstract Sample return missions play a significant role in planetary science by providing pristine extraterrestrial materials. JAXA's Hayabusa2 and NASA's OSIRIS‐REx missions have returned samples from the C‐type asteroids Ryugu and Bennu, respectively. The chemical and mineralogical compositions of these samples closely resemble those of CI chondrites,
Tetsuya Yokoyama, Guillaume Avice, Henner Busemann, Nicolas Dauphas, Daniel P. Glavin, Ashley J. King, Thorsten Kleine, Katharina Lodders, Frederic Moynier, Maria Schönbächler, Yoshinori Takano, Kun Wang, Hikaru Yabuta, Yuma Enokido, Ryota Fukai, Shogo Tachibana, Tomohiro Usui   +16 more
wiley   +1 more source

Chemical Evolution of a Protoplanetary Disk [PDF]

Proceedings of the International Astronomical Union, 2011
AbstractIn this paper we review recent progress in our understanding of the chemical evolution of protoplanetary disks. Current observational constraints and theoretical modeling on the chemical composition of gas and dust in these systems are presented.
openaire   +2 more sources

Mass inventory of the giant-planet formation zone in a solar nebula analog [PDF]

, 2017
The initial mass distribution in the solar nebula is a critical input to planet formation models that seek to reproduce today's Solar System. Traditionally, constraints on the gas mass distribution are derived from observations of the dust emission from ...
Bergin, Edwin A., Blake, Geoffrey A., Cleeves, L. Ilsedore, Schwarz, Kamber R., Zhang, Ke   +4 more
core   +3 more sources

Aqueous alteration in C2‐ung Bells through the analysis of carbonates – Does a CR origin ring true?

Meteoritics &Planetary Science, Volume 61, Issue 5, Page 927-941, May 2026.
Abstract Bells is an ungrouped carbonaceous chondrite that has in recent years been proposed as a CR‐an. This link to CR chondrites has previously been identified through the analysis of anhydrous silicates, for example, oxygen isotopic compositions of olivine (Marrocchi et al., 2023).
L. J. Riches, M. D. Suttle, I. A. Franchi, X. Zhao, M. M. Grady   +4 more
wiley   +1 more source

Evolution of PAHs in Protoplanetary Disks [PDF]

EAS Publications Series, 2011
Depending on whom you ask, PAHs are either the smallest dust particles or the largest gas-phase molecules in space. Whether referred to as gas or dust, these PAHs can contain up to 20% of the total cosmic carbon abundance and as such also play an important role in the carbon chemistry of protoplanetary disks.
openaire   +3 more sources

Shedding Light on the Origin of the Broken Misaligned Circumtriple Disk around GW Ori

The Astrophysical Journal Letters
We revisit the origin of the observed misaligned rings in the circumtriple disk around GW Ori. Previous studies appeared to disagree on whether disk breaking is caused by the differential precession driven in the disk by the triple star system.
Jeremy L. Smallwood, Stephen H. Lubow, Rebecca G. Martin, Rebecca Nealon   +3 more
doaj   +1 more source

PAHs in protoplanetary disks: emission and X-ray destruction [PDF]

, 2012
We study the PAH emission from protoplanetary disks. First, we discuss the dependence of the PAH band ratios on the hardness of the absorbed photons and the temperature of the stars.
Acke, Acke, Armitage, Asplund, Augereau, Baes, Bianchi, Bjorkman, Chase, Chiang, Compiegne, Doucet, Draine, Draine, Dullemond, Dwek, Ercolano, F. Heymann, Fleck, Galliano, Geers, Gordon, Guhathakurta, Habart, Hayashi, Heymann, Jayawardhana, Juvela, Keller, Krijt, Lagage, Lucy, Mathis, Mattioda, Mattioda, Min, Min, Miroshnichenko, Misselt, Peeters, Preibisch, R. Siebenmorgen, Robitaille, Robitaille, Salama, Schräpler, Schutte, Sellgren, Siebenmorgen, Siebenmorgen, Siebenmorgen, Siebenmorgen, Siebenmorgen, Siebenmorgen, Stelzer, Tielens, Uchida, van den Ancker, Vinkovic, Youdin, Zubko   +60 more
core   +1 more source

Composite Single‐Reference and Explicitly Correlated Multireference Calculations on the Mechanism of Pyrrole Pyrolysis

Journal of Physical Organic Chemistry, Volume 39, Issue 4, April 2026.
New calculations have been applied to the pyrolysis of pyrrole under shock‐tube conditions and to the radical‐radical reaction between allyl and •CN at low temperature and pressure, using the same mechanistic scheme for both. ABSTRACT The pyrolysis of pyrrole has previously been studied in shock‐tube experiments and in jet‐stirred reactors. The results
Barry K. Carpenter
wiley   +1 more source