The Dwarf Nova V893 Sco Does Not Have a Giant Planet

Abstract.Recent photometric and spectroscopic observations of the dwarf nova system Z Cha are discussed. Methods for constraining the system parameters are applied and the disc emissivity is deduced as a function of radius. Indications are found that the disc shrinks in size with increasing time after outburst.

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Giant planet formation with pebble accretion

Icarus ◽

10.1016/j.icarus.2014.01.036 ◽

2014 ◽

Vol 233 ◽

pp. 83-100 ◽

Cited By ~ 40

Author(s):

J.E. Chambers

Keyword(s):

Planet Formation ◽

Giant Planet

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AMBITION – comet nucleus cryogenic sample return

Experimental Astronomy ◽

10.1007/s10686-021-09770-4 ◽

2021 ◽

Author(s):

D. Bockelée-Morvan ◽

Gianrico Filacchione ◽

Kathrin Altwegg ◽

Eleonora Bianchi ◽

Martin Bizzarro ◽

...

Keyword(s):

Giant Planet ◽

Building Blocks ◽

Cometary Nucleus ◽

Comet Nucleus ◽

Surface Layers ◽

International Context ◽

Rosetta Mission ◽

Nucleus Surface ◽

And Storage ◽

Scientific Questions

AbstractWe describe the AMBITION project, a mission to return the first-ever cryogenically-stored sample of a cometary nucleus, that has been proposed for the ESA Science Programme Voyage 2050. Comets are the leftover building blocks of giant planet cores and other planetary bodies, and fingerprints of Solar System’s formation processes. We summarise some of the most important questions still open in cometary science and Solar System formation after the successful Rosetta mission. We show that many of these scientific questions require sample analysis using techniques that are only possible in laboratories on Earth. We summarize measurements, instrumentation and mission scenarios that can address these questions. We emphasize the need for returning a sample collected at depth or, still more challenging, at cryogenic temperatures while preserving the stratigraphy of the comet nucleus surface layers. We provide requirements for the next generation of landers, for cryogenic sample acquisition and storage during the return to Earth. Rendezvous missions to the main belt comets and Centaurs, expanding our knowledge by exploring new classes of comets, are also discussed. The AMBITION project is discussed in the international context of comet and asteroid space exploration.

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WD 1856 b: a close giant planet around a white dwarf that could have survived a common envelope phase

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3703 ◽

2020 ◽

Vol 501 (1) ◽

pp. 676-682

Author(s):

F Lagos ◽

M R Schreiber ◽

M Zorotovic ◽

B T Gänsicke ◽

M P Ronco ◽

...

Keyword(s):

White Dwarf ◽

Evolutionary History ◽

Giant Planet ◽

Asymptotic Giant Branch ◽

Orbital Energy ◽

Current Position ◽

Recombination Energy ◽

Additional Energy ◽

Common Envelope ◽

History Of

ABSTRACT The discovery of a giant planet candidate orbiting the white dwarf WD 1856+534 with an orbital period of 1.4 d poses the questions of how the planet reached its current position. We here reconstruct the evolutionary history of the system assuming common envelope evolution as the main mechanism that brought the planet to its current position. We find that common envelope evolution can explain the present configuration if it was initiated when the host star was on the asymptotic giant branch, the separation of the planet at the onset of mass transfer was in the range 1.69–2.35 au, and if in addition to the orbital energy of the surviving planet either recombination energy stored in the envelope or another source of additional energy contributed to expelling the envelope. We also discuss the evolution of the planet prior to and following common envelope evolution. Finally, we find that if the system formed through common envelope evolution, its total age is in agreement with its membership to the Galactic thin disc. We therefore conclude that common envelope evolution is at least as likely as alternative formation scenarios previously suggested such as planet–planet scattering or Kozai–Lidov oscillations.

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Giant planet formation

Astrophysics of Planet Formation ◽

10.1017/cbo9780511802225.007 ◽

2012 ◽

pp. 185-217

Author(s):

Philip J. Armitage

Keyword(s):

Planet Formation ◽

Giant Planet

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Forming terrestrial planets and delivering water

Proceedings of the International Astronomical Union ◽

10.1017/s174392131600572x ◽

2015 ◽

Vol 11 (A29B) ◽

pp. 427-430

Author(s):

Kevin J. Walsh

Keyword(s):

Planet Formation ◽

Semimajor Axis ◽

Giant Planet ◽

Terrestrial Planet ◽

Giant Planets ◽

Asteroid Belt ◽

Terrestrial Planets ◽

The Earth ◽

Building Models ◽

Rich Material

AbstractBuilding models capable of successfully matching the Terrestrial Planet's basic orbital and physical properties has proven difficult. Meanwhile, improved estimates of the nature of water-rich material accreted by the Earth, along with the timing of its delivery, have added even more constraints for models to match. While the outer Asteroid Belt seemingly provides a source for water-rich planetesimals, models that delivered enough of them to the still-forming Terrestrial Planets typically failed on other basic constraints - such as the mass of Mars.Recent models of Terrestrial Planet Formation have explored how the gas-driven migration of the Giant Planets can solve long-standing issues with the Earth/Mars size ratio. This model is forced to reproduce the orbital and taxonomic distribution of bodies in the Asteroid Belt from a much wider range of semimajor axis than previously considered. In doing so, it also provides a mechanism to feed planetesimals from between and beyond the Giant Planet formation region to the still-forming Terrestrial Planets.

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