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Related papers: Radioactive Planet Formation

200 papers

Magnetic fields play a crucial role at all stages of the formation of low mass stars and planetary systems. In the final stages, in particular, they control the kinematics of in-falling gas from circumstellar discs, and the launching and…

Solar and Stellar Astrophysics · Physics 2015-05-19 S. G. Gregory , M. Jardine , C. G. Gray , J. -F. Donati

Brown dwarfs and very low mass stars are a significant fraction of stars in our galaxy, and they are interesting laboratories to investigate planet formation in extreme conditions of low temperature and densities. In addition, the dust…

Earth and Planetary Astrophysics · Physics 2022-10-14 Paola Pinilla

The formation of planets with gaseous envelopes takes place in protoplanetary accretion discs on time-scales of several millions of years. Small dust particles stick to each other to form pebbles, pebbles concentrate in the turbulent flow…

Earth and Planetary Astrophysics · Physics 2015-02-25 Bertram Bitsch , Anders Johansen , Michiel Lambrechts , Alessandro Morbidelli

Assuming that giant planets are formed in thin protoplanetary discs, a '3D' system can form, provided that the mutual inclination is excited by some dynamical mechanism. Resonant interactions and close planetary encounters are thought to be…

Earth and Planetary Astrophysics · Physics 2015-06-04 A. -S. Libert , K. Tsiganis

Star formation generally proceeds inside-out, with overdense regions inside protostellar cores collapsing rapidly and progressively less dense regions following later. Consequently, a small protostar will form early in the evolution of a…

Astrophysics · Physics 2009-11-11 Mark R. Krumholz

We develop a simple model to predict the radial distribution of planetesimal formation. The model is based on the observed growth of dust to mm-sized particles, which drift radially, pile-up, and form planetesimals where the stopping time…

Earth and Planetary Astrophysics · Physics 2016-08-31 Philip J. Armitage , Josh A. Eisner , Jacob B. Simon

The increasing number of newly detected exoplanets at short orbital periods raises questions about their formation and migration histories. A particular puzzle that requires explanation arises from one of the key results of the Kepler…

Earth and Planetary Astrophysics · Physics 2019-10-16 Mario Flock , Neal J. Turner , Gijs D. Mulders , Yasuhiro Hasegawa , Richard P. Nelson , Bertram Bitsch

The compact multi-transiting planet systems discovered by Kepler challenge planet formation theories. Formation in situ from disks with radial mass surface density, $\Sigma$, profiles similar to the minimum mass solar nebula (MMSN) but…

Earth and Planetary Astrophysics · Physics 2015-06-16 Sourav Chatterjee , Jonathan C. Tan

Short lived radionuclides (SLRs) like $^{26}$Al are synthesized by massive stars and are a byproduct of star formation. The abundances of SLRs in the gas of a star-forming galaxy are inversely proportional to the gas consumption time. The…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Brian C. Lacki

We examine changes in the molecular abundances resulting from increased heating due to a self-luminous planetary companion embedded within a narrow circumstellar disk gap. Using 3D models that include stellar and planetary irradiation, we…

Solar and Stellar Astrophysics · Physics 2015-05-29 L. Ilsedore Cleeves , Edwin A. Bergin , Tim J. Harries

Stars with masses of >~ 20 solar masses have short Kelvin times that enable them to reach the main sequence while still accreting from their natal clouds. The resulting nuclear burning produces a huge luminosity and a correspondingly large…

Astrophysics · Physics 2009-11-11 Mark R. Krumholz , Richard I. Klein , Christopher F. McKee

The composition of planets is largely determined by the chemical and dynamical evolution of the disk during planetesimal formation and growth. To predict the diversity of exoplanet compositions, previous works modeled planetesimal…

Earth and Planetary Astrophysics · Physics 2014-05-14 John Moriarty , Nikku Madhusudhan , Debra Fischer

The composition of rocky exoplanets in the context of stars' composition provides important constraints to formation theories. In this study, we select a sample of exoplanets with mass and radius measurements with an uncertainty <25% and…

Earth and Planetary Astrophysics · Physics 2020-10-21 Mykhaylo Plotnykov , Diana Valencia

We have searched a sample of 151 young, energetic pulsars for periodic variation in pulse time-of-arrival arising from the influence of planetary companions. We are sensitive to objects with masses two orders of magnitude lower than those…

High Energy Astrophysical Phenomena · Physics 2015-08-19 Matthew Kerr , Simon Johnston , George Hobbs , Ryan M. Shannon

The formation of super-Earths, the most abundant planets in the Galaxy, remains elusive. These planets have masses that typically exceed that of the Earth by a factor of a few; appear to be predominantly rocky, although often surrounded by…

Earth and Planetary Astrophysics · Physics 2023-01-13 Konstantin Batygin , Alessandro Morbidelli

Rocky planets in compact configurations are the most common ones around M dwarfs. Many disks around very low mass stars (between 0.1 and 0.5 M$_\odot$) are rather compact and small (without observable substructures and radius less than 20…

Earth and Planetary Astrophysics · Physics 2024-08-05 M. Sanchez , N. van der Marel , M. Lambrechts , G. D. Mulders , O. M. Guerra-Alvarado

Recent discoveries of strongly misaligned transiting exoplanets pose a challenge to the established planet formation theory which assumes planetary systems to form and evolve in isolation. However, the fact that the majority of stars…

Earth and Planetary Astrophysics · Physics 2012-02-01 Ingo Thies , Pavel Kroupa , Simon P. Goodwin , Dimitris Stamatellos , Anthony P. Whitworth

Energy in stars is provided by nuclear reactions, which, in many cases, produce radioactive nuclei. When stable nuclei are irradiated by a flux of protons or neutrons, capture reactions push stable matter out of stability into the regime of…

Solar and Stellar Astrophysics · Physics 2022-09-21 Maria Lugaro , Alessandro Chieffi

Stars grow by accreting gas that has an evolving composition owing to the growth and inward drift of dust (pebble wave), the formation of planetesimals and planets, and the selective removal of hydrogen and helium by disk winds. We…

Solar and Stellar Astrophysics · Physics 2021-11-17 Masanobu Kunitomo , Tristan Guillot

In this paper, we calculate simulated scattered light images of a circumstellar disk in which a planet is forming by gravitational instability. The simulated images bear no correlation to the vertically integrated surface density of the…

Astrophysics · Physics 2009-11-13 Hannah Jang-Condell , Alan P. Boss