Are There Unstable Planetary Systems around White Dwarfs?

By J. Debes, S. Sigurdsson. 2002

360 citations recorded by the source corpus.

The presence of planets around solar-type stars suggests that many white dwarfs should have relic planetary systems. While planets closer than ~5 AU will most likely not survive the post-main-sequence lifetime of their parent star, any planet with semimajor axis greater than 5 AU will survive, and its semimajor axis will increase as the central star loses mass. Since the stability of adjacent orbits to mutual planet-planet perturbations depends on the ratio of the planet mass to the central star's mass, some planets in previously stable orbits around a star undergoing mass loss will become unstable. We show that when mass loss is slow, systems of two planets that are marginally stable can become unstable to close encounters, while for three planets the timescale for close approaches decreases significantly with increasing mass ratio. These processes could explain the presence of anomalous IR excesses around white dwarfs that cannot be explained by close companions, such as G29-38, and may also be an important factor in explaining the existence of DAZ white dwarfs. The onset of instability through changing mass ratios will also be a significant effect for planetary embryos gaining mass in protoplanetary disks.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/9744cb95fbf45e940ecaf1c19cbb985e473b5301

How researchers see this paper

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In Astronomy and Astrophysics

1. J. Farihi
2. Michael Jura
3. B. Zuckerman
4. A. Mustill
5. Amy Bonsor
6. M. C. Wyatt
7. D. Koester
8. B. Gänsicke

In Instrumentation

1. J. Farihi
2. Michael Jura
3. A. Mustill
4. M. C. Wyatt
5. Amy Bonsor
6. B. Zuckerman
7. D. Koester
8. B. Gänsicke

Citations in the corpus

• Can Planets Survive Stellar Evolution? (2007, background): “In recent years, the quest for Jupiter-like giant planets has been extended to a completely different kind of host: white dwarfs (e.g., Debes & Sigurdsson 2002; Farihi et al. 2005; Friedrich et al. 2005).”
• The frequency of planetary debris around young white dwarfs (2014, background): “…events can and probably do occur as frequent at white dwarfs hotter than≈23 000 K, and dynamically this is actually favored at earlier cooling ages (Debes & Sigurdsson 2002; Bonsor & Wyatt 2011; Veras et al. 2013; Frewen & Hansen 2014), the debris will rapidly sublimate, forming a purely gaseous…”
• A Tidally Disrupted Asteroid around the White Dwarf G29-38 (2003, methodology): “…we present a model where the dust around G29-38 is so close to the star that it lies inside the Roche radius where an asteroid parent-body would have been tidally disrupted, a process suggested by Debes & Sigurdsson (2002) to destroy comets and that would produce the observed circumstellar dust.”
• INFRARED SIGNATURES OF DISRUPTED MINOR PLANETS AT WHITE DWARFS (2009, background): “Minor planet belts may become significantly depleted on these timescales or gravitational perturbations may subside on shorter timescales via dynamical rearrangement (Jura 2008; Bottke et al. 2005; Debes & Sigurdsson 2002).”
• Distant future of the Sun and Earth revisited (2008, background): “Nonetheless,theasteroidalfly-byschemehasitsown problems,notleastthedangerofabenigncloseapproachturning intoacatastrophicaccidentalcollision,andpossiblyalsotriggering orbital instability – cf. also Debes & Sigurdsson (2002).”
• The Dust Cloud around the White Dwarf G29-38 (2005, background): “The other major model for white dwarf photospheric metals is cometary impact (Zuckerman & Reid 1998; Debes & Sigurdsson 2002).”
• The Chemical Composition of an Extrasolar Minor Planet (2007, background): “In the latter model accreted metals were suggested to have their origin in comets (Alcock et al. 1986; Debes & Sigurdsson 2002) or in asteroids (Jura 2003; Debes & Sigurdsson 2002).”
• ANCIENT PLANETARY SYSTEMS ARE ORBITING A LARGE FRACTION OF WHITE DWARF STARS (2010, methodology): “…to the conclusion that the source of the dusty disk material are rocky objects, such as asteroids, that have been gravitationally perturbed into orbits that take them within the Roche radius of the white dwarf where they are shredded into tiny dust particles (Debes & Sigurdsson 2002; Jura 2003).”
• Externally Polluted White Dwarfs with Dust Disks (2007, background): “A promising model to explain these data is that a minor-body is perturbed (Debes & Sigurdsson 2002) to orbit within the tidal radius of the star where it is destroyed and a dusty disk is produced (Jura 2003).”
• The great escape: how exoplanets and smaller bodies desert dying stars (2011, methodology): “In these integrations, one may incorporate mass-loss (i) as a separate differential equation, (ii) by explicitly removing mass from the primary according to a given prescription, or, alternatively (iii) by adding mass to the secondary (Debes & Sigurdsson 2002).”
• Circumstellar Debris and Pollution at White Dwarf Stars (2016, background): “Rather than impacting the star, an asteroid perturbed into a highly eccentric orbit passes within the stellar Roche limit and is torn apart by gravitational tides (Debes & Sigurdsson, 2002).”
• Debris Disks around White Dwarfs: The DAZ Connection (2006, background): “Even though planets within 5 AU of their parent stars will most likely not survive the red giant phases, most of the outer planets, Kuiper belt objects, and Oort-like comet clouds are predicted to survive around white dwarf stars (Debes & Sigurdsson 2002; Burleigh et al. 2002).”
• FORETELLINGS OF RAGNARÖK: WORLD-ENGULFING ASYMPTOTIC GIANTS AND THE INHERITANCE OF WHITE DWARFS (2012, background): “Such delivery mechanisms require dynamical instability, whether local instability of the metalliferous planetesimals (Bonsor et al. 2011; Bonsor & Wyatt 2012; Debes et al. 2012) or wholesale global instability (Debes & Sigurdsson 2002, D. Veras et al., MN- RAS, submitted).”
• POLLUTION OF SINGLE WHITE DWARFS BY ACCRETION OF MANY SMALL ASTEROIDS (2008, background): “(1) The near-infrared excess discovered around G29-38 (Zuckerman & Becklin 1987) was shown to be produced by dust (Graham et al. 1990) that likely resulted from an orbitally-perturbed minor planet (Debes & Sigurdsson 2002) that passed within the tidal-radius of the host star (Jura 2003).”
• Simulations of two-planet systems through all phases of stellar evolution: implications for the instability boundary and white dwarf pollution (2013, methodology): “Debes & Sigurdsson (2002) considered adiabatic evolution of twoplanet systems while exposed to a 1 M star losing half of its mass over 1000 planetary orbits.”
• Dynamical effects of stellar mass-loss on a Kuiper-like belt (2011, background): “Multiplanet systems may also become dynamically unstable poststellar mass-loss (Debes & Sigurdsson 2002), and planets may be ejected or they may collide with the star.”
• The chemical diversity of exo-terrestrial planetary debris around white dwarfs (2012, background): “…analogue asteroids or minor planets (Graham et al. 1990; Jura 2003), or Kuiper-belt like objects (Bonsor et al. 2011), likely perturbed by unseen planets (Debes & Sigurdsson 2002; Debes et al. 2012), is the most likely origin of photospheric metals in many, if not most polluted white dwarfs.”