How dust particles orbiting white dwarfs can reveal undetected co-orbiting exoplanets
Year: 2026
Type: article
Abstract: Context . Mounting observations of transiting dusty debris orbiting white dwarfs (WDs) display complex signatures that often feature orbital period drifts. The asteroid or planet progenitor of this debris might still be partly intact on a near-circular orbit that is inclined or coplanar, with a period that is similar to that of the dust. Alternatively, the debris could persist concurrently with other intact asteroids or planets that had tidally circularised around the WD at a later time, but still remain directly unobservable. Aims . We sought to first improve the identification of this detectability threshold by expanding our previous investigation of the WD-secondary-dust co-orbital circular restricted three-body problem (CRTBP) to higher secondary masses corresponding to Ceres, Mercury, Earth, and Neptune. Next, we continued to explore the link between the analytic and numerical characterisations of the CRTBP. Methods . First, we computed families of periodic orbits in the 1/1 mean-motion-resonance (MMR) in both the planar and spatial CRTBP cases, where the dust is on an arbitrarily eccentric orbit. Second, we generated global phase space portraits with dynamical stability (DS) maps. Third, we determined observational links with debris located in very close proximity to WDs via N -body simulations. Results . For each method we applied, we report a novel set of results. These include three newly discovered bifurcation points, B T 4 , B cs 4 , and B cs 5 , two branches of asymmetric periodic orbits, called A 2 and A 3 , at high dust eccentricity regime in the 2D-CRTBP, and two families of symmetric orbits in the 3D-CRTBP. The maps reveal stability domains as a function of the dust’s eccentricity, argument of pericentre, and slight semi-major axis deviations from the 1/1 MMR. The N -body simulations reveal that over 10 yr, mass analogues of Mercury, Earth, and Neptune generate orbital period deviations in the dust of, respectively, ∼1–10 s, ∼10–100 s, and over 100 s. Conclusions . We identified strong links between analytic periodic orbits, numerical DS maps, and numerical N -body simulations. The observed period deviations are easily detectable, aiding in efforts to obtain indirect detections of exoplanets orbiting WDs.
Source: Astronomy and Astrophysics
Authors: Kyriaki I. Antoniadou, Dimitri Veras
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7214051850