Circumstellar debris and pollution at white dwarf stars

Farihi, Jay

doi:10.1016/j.newar.2016.03.001

Cited by 300 publications

(282 citation statements)

References 195 publications

(434 reference statements)

Supporting

Mentioning

269

Contrasting

Unclassified

Order By: Relevance

“…Additional evidence for planetesimals falling into the central star comes from the atmospheric pollution in heavy elements observed in white dwarfs (see Farihi 2016 for a review). Spectroscopic studies of a large sample of cool, hydrogen-rich white dwarfs has established a minimum frequency of 30% for the pollution phenomenon in these objects (Zuckerman et al 2003;Koester et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Extreme secular excitation of eccentricity inside mean motion resonance

Pichierri

Morbidelli

Lai

2017

A&A

View full text Add to dashboard Cite

Context. It is well known that asteroids and comets fall into the Sun. Metal pollution of white dwarfs and transient spectroscopic signatures of young stars like β-Pic provide growing evidence that extra solar planetesimals can attain extreme orbital eccentricities and fall into their parent stars. Aims. We aim to develop a general, implementable, semi-analytical theory of secular eccentricity excitation of small bodies (planetesimals) in mean motion resonances with an eccentric planet valid for arbitrary values of the eccentricities and including the short-range force due to General Relativity. Methods. Our semi-analytic model for the restricted planar three-body problem does not make use of series expansion and therefore is valid for any eccentricity value and semi-major axis ratio. The model is based on the application of the adiabatic principle, which is valid when the precession period of the longitude of pericentre of the planetesimal is much longer than the libration period in the mean motion resonance. In resonances of order larger than 1 this is true except for vanishingly small eccentricities. We provide prospective users with a Mathematica notebook with implementation of the model allowing direct use. Results. We confirm that the 4:1 mean motion resonance with a moderately eccentric (e < ∼ 0.1) planet is the most powerful one to lift the eccentricity of planetesimals from nearly circular orbits to star-grazing ones. However, if the planet is too eccentric, we find that this resonance is unable to pump the planetesimal's eccentricity to a very high value. The inclusion of the General Relativity effect imposes a condition on the mass of the planet to drive the planetesimals into star-grazing orbits. For a planetesimal at ∼1 AU around a solar mass star (or white dwarf), we find a threshold planetary mass of about 17 Earth masses. We finally derive an analytical formula for this critical mass. Conclusions. Planetesimals can easily fall into the central star even in the presence of a single moderately eccentric planet, but only from the vicinity of the 4:1 mean motion resonance. For sufficiently high planetary masses the General Relativity effect does not prevent the achievement of star-grazing orbits.

show abstract

Section: Introductionmentioning

confidence: 99%

Extreme secular excitation of eccentricity inside mean motion resonance

Pichierri

Morbidelli

Lai

2017

A&A

View full text Add to dashboard Cite

show abstract

“…Abundant observations reveal substantial clues (Farihi 2016), but theoretical explanations are lacking (e.g. Veras 2016a).…”

Section: Introductionmentioning

confidence: 99%

“…One feature common to all of these white dwarf systems is metal pollution (see Farihi 2016 andVeras 2016a for review articles). White dwarf atmospheres break up accreted material into their constituent chemical elements and then stratify them according to weight (Schatzman 1945).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The fate of exomoons in white dwarf planetary systems

Payne

Veras

Gänsicke

et al. 2016

Mon. Not. R. Astron. Soc.

View full text Add to dashboard Cite

Roughly 1000 white dwarfs are known to be polluted with planetary material, and the progenitors of this material are typically assumed to be asteroids. The dynamical architectures which perturb asteroids into white dwarfs are still unknown, but may be crucially dependent on moons liberated from parent planets during post-main-sequence gravitational scattering. Here, we trace the fate of these exomoons, and show that they more easily achieve deep radial incursions towards the white dwarf than do scattered planets. Consequently, moons are likely to play a significant role in white dwarf pollution, and in some cases may be the progenitors of the pollution itself.

show abstract

“…Livio & Soker 1984;Rasio & Livio 1996;Duncan & Lissauer 1998;Villaver & Livio 2007). There is also accumulating evidence of planetary or asteroidal debris surrounding white dwarfs and polluting their atmospheres (see recent reviews by Farihi 2016 andVeras 2016). A planet's survival depends both on the initial orbital separation, and on its mass.…”

Section: Introductionmentioning

confidence: 99%

Tatooine’s Future: The Eccentric Response of Kepler’s Circumbinary Planets to Common-Envelope Evolution of Their Host Stars

Kostov

Moore

Tamayo

et al. 2016

ApJ

View full text Add to dashboard Cite

Inspired by the recent Kepler discoveries of circumbinary planets orbiting nine close binary stars, we explore the fate of the former as the latter evolve off the main sequence. We combine binary star evolution models with dynamical simulations to study the orbital evolution of these planets as their hosts undergo common-envelope stages, losing in the process a tremendous amount of mass on dynamical timescales. Five of the systems experience at least one Roche-lobe overflow and common-envelope stages (Kepler-1647 experiences three), and the binary stars either shrink to very short orbits or coalesce; two systems trigger a double-degenerate supernova explosion. Kepler's circumbinary planets predominantly remain gravitationally bound at the end of the common-envelope phase, migrate to larger orbits, and may gain significant eccentricity; their orbital expansion can be more than an order of magnitude and can occur over the course of a single planetary orbit. The orbits these planets can reach are qualitatively consistent with those of the currently known post-commonenvelope, eclipse-time variations circumbinary candidates. Our results also show that circumbinary planets can experience both modes of orbital expansion (adiabatic and -2 -non-adiabatic) if their host binaries undergo more than one common-envelope stage; multiplanet circumbinary systems like Kepler-47 can experience both modes during the same common-envelope stage. Additionally, unlike Mercury orbiting the Sun, a circumbinary planet with the same semi-major axis can survive the common envelope evolution of a close binary star with a total mass of 1 M .

show abstract

Circumstellar debris and pollution at white dwarf stars

Cited by 300 publications

References 195 publications

Extreme secular excitation of eccentricity inside mean motion resonance

Extreme secular excitation of eccentricity inside mean motion resonance

The fate of exomoons in white dwarf planetary systems

Tatooine’s Future: The Eccentric Response of Kepler’s Circumbinary Planets to Common-Envelope Evolution of Their Host Stars

Contact Info

Product

Resources

About