A Possible Dwarf Planet Candidate and Seven Other Distant-object Candidates in Rubin DP2

We report a possible dwarf planet candidate (internal designation MGR-DP2-A) in Rubin Data Preview 2 (DP2): ten detections on six nights, 2025 July 2–19, consistent with a slow-moving object at a nominal distance of about 76 au. Its absolute magnitude (H_r ≈ 3.8–4.0) implies a diameter of roughly 465–880 km for assumed albedos of 0.05–0.15. It needs independent image-level verification. The same blind moving-object search of 426 southern Galactic-plane fields found seven other trans-Neptunian object candidates (MGR-DP2-B to MGR-DP2-H), including MGR-DP2-C with a 17-year observational arc (2008–2025). In accordance with the Rubin Data Policy (RDO-13), this record contains only derived data products; DP2 measurements are given as DiaSource identifiers only.