1,2,3,1,1,1,2,1,1,1,1,- 1DiRAC Institute, University of Washington, Seattle, USA
- 2LSST Interdisciplinary Network for Collaboration and Computing, Tucson, USA
- 3Northern Arizona University, Flagstaff, USA
- 4McWilliams Center for Cosmology, Carnegie Mellon University, Pittsburgh, USA
- 5Center for Astrophysics, Harvard & Smithsonian, Cambridge, USA
- 6Concordia University of Edmonton, Edmonton, Canada
The population of Trans-Neptunian Objects (TNOs) offers critical insights into the formation and dynamical evolution of the solar system and planetary systems elsewhere. Despite an estimated mass 20–100 times that of the asteroid belt, fewer than 5,000 TNOs have been discovered to date — a stark contrast to the 1.2 million cataloged Main-belt asteroids. This disparity stems primarily from the faintness of TNOs, whose large heliocentric distances push them below the single-exposure 5-sigma magnitude limits of most surveys.
Shift-and-stack techniques can help. By aligning and co-adding images along hypothetical minor planet trajectories, shift-and-stack searches can recover objects far fainter than the single-epoch detection limit. Our software, Kernel-Based Moving Object Detection (KBMOD; Whidden et al. 2019, Smotherman et al. 2021, Bektešević et al. 2025 in prep.), has demonstrated success in targeted surveys including the DECam Ecliptic Exploration Project (DEEP; see, e.g., Trilling et al. 2024, Trujillo et al. 2024, Smotherman et al. 2024, Napier et al. 2024, Bernardinelli et al. 2024, Strauss et al. 2024) and the New Horizons Subaru TNO Survey (Fraser et al. 2024), both optimized for TNO detection but limited in on-sky coverage.
The upcoming Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) will change the landscape dramatically. LSST will survey the entire southern sky to single-visit depths of approximately 24th magnitude, with the potential to discover about 30,000 TNOs (Ivezić et al. 2019; Kurlander et al. 2025). Science Validation observations began in late 2024 using the LSST Commissioning Camera (ComCam), which features a central 9-CCD raft (144 megapixels) and a 40-by-40 arcminute field of view. ComCam has already acquired about 16,000 images, roughly 2,000 of which are earmarked for Data Preview 1 (DP1).
Adapting KBMOD for Rubin data introduces new challenges, including the massive data volume, observations in multiple filters, and a survey cadence not optimized for TNO discovery. We address these issues through several innovations. Chief among them is a novel method for accounting for Earth’s motion by reprojecting images into a reflex-corrected barycentric frame, enabling shift-and-stack searches that remain coherent across days to weeks. Additionally, we describe our handling of variable telescope rotation, heterogeneous filters, and efficient integration with the Rubin Butler data access system.
We present preliminary results from KBMOD searches of Science Validation data and discuss the prospects and challenges for TNO discovery in the LSST era.
How to cite: Chandler, C. O., Bektešvić, D., Bernardinelli, P., Kubica, J., Connolly, A., West, M., Beebe, W., Oldag, D., Frissell, M., Stetzler, S., Kurlander, J., Heinze, A., Holman, M., Kalmbach, J. B., Christofferson, C., Jurić, M., Portillo, S., Smotherman, H., and Whidden, P.: Faint Solar System Object Discovery in Rubin Data with Parallax-Corrected Shift-and-Stack, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-1181, https://doi.org/10.5194/epsc-dps2025-1181, 2025.
