Overview
- Papers posted to arXiv on Wednesday report 27 trans‑Neptunian objects (TNOs) found with JWST NIRCam in the deepest Solar System survey to date.
- The search used a shift‑and‑stack technique plus a machine‑learning filter to reach m_F150W2 ≈ 28.8–29.3 and detect objects as faint as ~10 km in diameter assuming 15% albedo.
- Coordinated HST imaging recovered 13 of the JWST detections and provided optical–NIR colours and rotational lightcurves for small (≤40 km) objects.
- Small cold‑classical TNOs match the same narrow optical–NIR colour sequence as much larger cold classicals while dynamically hot TNOs show a broader range of colours.
- Both cold and hot subpopulations follow a common power‑law luminosity slope and show fewer very small bodies than some formation models predicted, prompting a planned expanded JWST program to probe down toward one‑kilometre objects.