Exoplanets, -moons, -comets

A Pan-STARRS Search For Distant Planets: Part 1

By Keith Cowing
Status Report
astro-ph.EP
June 7, 2025
Filed under , , , , , ,
A Pan-STARRS Search For Distant Planets: Part 1
The coverage of the Pan-STARRS1 data used in this search, from 2009 April 2 until 2017 November, shown in a Mollweide projection in equatorial coordinates (RA 0 deg is at the center of the plot, with RA increasing to the left). The colors encode, with a linear scale, the number of exposures that cover the region, assuming a circular field of view with a 1.6 deg angular radius, ignoring the ∼ 68% fill factor. The ten Medium Deep fields are shown for completeness. (Note that we skip any data from the Medium Deep fields, as well as from a few exposures for which the processing seems to have failed.) Each has thousands of exposures; we cap the maximum at 600 to keep those fields from dominating the color scale. The median number of exposures is ∼150. A fraction of the sky was not observed at all, and a few regions were observed more than ∼ 400 times. The center of the plot is 0 hr and 0. — astro-ph.EP

We present a search for distant planets in Pan-STARRS1. We calibrated our search by injecting an isotropic control population of synthetic detections into Pan-STARRS1 source catalogs, providing a high-fidelity alternative to injecting synthetic sources at the image level.

We found that our method is sensitive to a wide range of distances, as well as all rates and directions of motion. We identified 692 solar system objects (109 of which are not yet listed in the Minor Planet Center’s database), including 642 TNOs, 23 of which are dwarf planets.

By raw number of detections, this makes our search the third most productive Kuiper Belt survey to date, in spite of the fact that we did not explicitly search for objects closer than 80 au.

Although we did not find Planet Nine or any other planetary objects, we were able to show that the remaining parameter space for Planet Nine is highly concentrated in the galactic plane.

Matthew J. Holman, Kevin J. Napier, Matthew J. Payne, Jacob A. Kurlander

Comments: 23 pages, 9 figures. PSJ accepted 2025 May 23
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2506.02144 [astro-ph.EP] (or arXiv:2506.02144v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2506.02144
Focus to learn more
Submission history
From: Matthew J. Holman
[v1] Mon, 2 Jun 2025 18:13:46 UTC (11,019 KB)
https://arxiv.org/abs/2506.02144
Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

Follow on Twitter
MORE FROM Exoplanets, -moons, -comets