Determine the eccentricity distribution of white-dwarf exoplanets

Determine the eccentricity distribution of white-dwarf exoplanets to establish appropriate eccentricity priors for occurrence-rate and detection-yield calculations.

Background

The transit yield increases with eccentricity because the geometric transit probability scales as 1/(1−e2)1/(1-e^2), whereas the phase-curve yield decreases because eccentric motion causes undersampling near periastron. The paper therefore fixes eccentricity to zero when reporting period-averaged yields rather than marginalizing over an empirical distribution. Measuring the eccentricity distribution would allow more realistic population-level yield estimates.

References

Because the eccentricity distribution of WD exoplanets is unconstrained, the $\overline{N}_\mathrm{eff}$ values reported in Section~\ref{subsec:results_yield} assume $e=0$.

— Detecting White Dwarf Exoplanets in the Roman Era  (2609.09481 - Lin et al., 8 Sep 2026) in Section 3.2.3, Eccentricity Dependence; Section 5.1, Effective Survey Size and Required Occurrence Rate