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Weizsäcker, v.; Meggendorfer,

doi:10.1007/bf01842507

Cited by 5 publications

(5 citation statements)

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“…So from the mid‐90s onwards research began to focus on what conditions might allow higher densities to be achieved, densities that could trigger a gravitational collapse or could accelerate collisional growth to a practicable extent. One suggestion, based on the lapsed theories of Weizsäcker (1943), is that dust might become trapped in and amongst long‐lived vortices in the circumstellar disc, leading to just such high‐density concentrations (Barge & Sommeria 1995; Tanga et al 1996; Hodgson & Brandenburg 1998; Chavanis 2000; Godon & Livio 2000; Supulver & Lin 2000; de la Fuente Marcos & Barge 2001; Johansen, Andersen & Brandenburg 2004; Barranco & Marcus 2005; Heng & Kenyon 2010). As well as vortices in the plane of the disc, Klahr & Henning (1997) found that millimetre scale particles can be effectively trapped and concentrated within eddies with rotation axes parallel to the disc midplane, e.g.…”

Section: Introductionmentioning

confidence: 99%

On the accumulation of planetesimals near disc gaps created by protoplanets

Ayliffe

Laibe

Price

et al. 2012

Monthly Notices of the Royal Astronomical Society

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We have performed three‐dimensional two‐fluid (gas–dust) hydrodynamical models of circumstellar discs with embedded protoplanets (3–333 M⊕) and small solid bodies (radii 10 cm to 10 m). We find that high‐mass planets (≳ Saturn mass) open sufficiently deep gaps in the gas disc such that the density maximum at the outer edge of the gap can very efficiently trap metre‐sized solid bodies. This allows the accumulation of solids at the outer edge of the gap as solids from large radii spiral inwards to the trapping region. This process of accumulation occurs fastest for those bodies that spiral inwards most rapidly, typically metre‐sized boulders, whilst smaller and larger objects will not migrate sufficiently rapidly in the discs lifetime to benefit from the process. Around a Jupiter mass planet we find that bound clumps of solid material, as large as several Earth masses, may form, potentially collapsing under self‐gravity to form planets or planetesimals. These results are in agreement with Lyra et al., supporting their finding that the formation of a second generation of planetesimals or of terrestrial mass planets may be triggered by the presence of a high‐mass planet.

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Section: Introductionmentioning

confidence: 99%

On the accumulation of planetesimals near disc gaps created by protoplanets

Ayliffe

Laibe

Price

et al. 2012

Monthly Notices of the Royal Astronomical Society

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“…Protoplanetary disks are accretion disks, which evolution was mathematically described in the "classical" theoretical studies [4][5][6]. Their fundamental physical properties are described by the conservation laws for energy and angular momentum.…”

Section: Protoplanetary Disk Structurementioning

confidence: 99%

Accretion disks around young stars: the cradles of planet formation

Semenov

2020

Europhysics News

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Protoplanetary disks around young stars are the birth sights of planetary systems like our own. Disks represent the gaseous dusty matter left after the formation of their central stars. The mass and luminosity of the star, initial disk mass and angular momentum, and gas viscosity govern disk evolution and accretion. Protoplanetary disks are the cosmic nurseries where microscopic dust grains grow into pebbles, planetesimals, and planets. Protoplanetary Disks as Analogues of Young Solar Systems

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“…Since the late 1930s, when von Weizsäcker [52] and Bethe [53] independently proposed sets of fusion reactions by which stars convert hydrogen to helium, it is well established that the carbon-nitrogen-oxygen cycles is a mechanism for hydrogen burning in stars. The dominant sequence of reactions for this cycle is the following starts.…”

Section: Cno and Hot Cno Cyclesmentioning

confidence: 99%

Reanalysis of $^{13}$N($p,γ$)$^{14}$O reaction and its role in stellar CNO cycle

Dubovichenko,

Kezerashvili,

Burkova

et al. 2020

Preprint

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Within the framework of the modified potential cluster model with forbidden states, the 13 N(p, γ) 14 O reaction rate and the astrophysical S-factor are considered. It is shown that the first p 13 N resonance determines the S-factor and contributions of the M 1 and E2 transitions are negligible at energies E < 1 MeV, but are significant at high energies. The S-factor strongly depends on the 3 S1 resonance parameters. The influence of the width of the 3 S1 resonance on S-factor is demonstrated. The reaction rate is calculated and an analytical approximation for the reaction rate is proposed. A comparison of our calculation with existing data is addressed. Results of our calculations for the 13 N(p, γ) 14 O reaction rate provide the contribution to the steadily improving reaction rate database libraries. Our calculations of the 13 N(p, γ) 14 O reaction rate along with results for the rates of 14 N(p, γ) 15 O and 12 C(p, γ) 13 N processes provide the temperature range 0.13 < T9 < 0.97 for the conversion of CNO cycle to the HCNO cycle. Our results demonstrate that at early stages of a nova explosion at temperatures about 0.1 T9 and at late stages of evolution of supermassive stars at temperatures about 1.0 T9 the ignition of the HCNO cycle could occur at much lower densities of a stellar medium.

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Cited by 5 publications

References 0 publications

On the accumulation of planetesimals near disc gaps created by protoplanets

On the accumulation of planetesimals near disc gaps created by protoplanets

Accretion disks around young stars: the cradles of planet formation

Reanalysis of $^{13}$N($p,γ$)$^{14}$O reaction and its role in stellar CNO cycle

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