Luca Broggi*, Nicholas C. Stone, Taeho Ryu, Elisa Bortolas, Massimo Dotti, Matteo Bonetti, Alberto Sesana

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Two-body relaxation may drive stars onto near-radial orbits around a massive black hole, resulting in a tidal disruption event (TDE). In some circumstances, stars are unlikely to undergo a single terminal disruption, but rather to have a sequence of many grazing encounters with the black hole. It has long been unclear what is the physical outcome of this sequence: each of these encounters can only liberate a small amount of stellar mass, but may significantly alter the orbit of the star. We study the phenomenon of repeating partial tidal disruptions (pTDEs) by building a semi-analytical model that accounts for mass loss and tidal excitation. In the empty loss cone regime, where two-body relaxation is weak, we estimate the number of consecutive partial disruptions that a star can undergo, on average, before being significantly affected by two-body encounters. We find that in this empty loss cone regime, a star will be destroyed in a sequence of weak pTDEs, possibly explaining the tension between the low observed TDE rate and its higher theoretical estimates.

Original languageEnglish
JournalOpen Journal of Astrophysics
StatePublished - 2024

Bibliographical note

Publisher Copyright:
© 2024, National University of Ireland Maynooth. All rights reserved.


  • astrophysics of galaxies
  • black hole physics
  • black holes
  • galactic nuclei
  • high-energy astrophysical phenomena
  • numerical methods
  • partial tidal disruptions
  • semi-analytical methods
  • solar and stellar astrophysics
  • tidal disruptions


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