What if Planet 9 is a Primordial Black Hole?

Scholtz, Jakub; Unwin, James

Abstract

We highlight that the anomalous orbits of trans-Neptunian objects (TNOs) and an excess in microlensing events in the 5-year Optical Gravitational Lensing Experiment data set can be simultaneously explained by a new population of astrophysical bodies with mass several times that of the Earth (M⊕). We take these objects to be primordial black holes (PBHs) and point out the orbits of TNOs would be altered if one of these PBHs was captured by the Solar System, inline with the Planet 9 hypothesis. Capture of a free floating planet is a leading explanation for the origin of Planet 9, and we show that the probability of capturing a PBH instead is comparable. The observational constraints on a PBH in the outer Solar System significantly differ from the case of a new ninth planet. This scenario could be confirmed through annihilation signals from the dark matter microhalo around the PBH.

Citation

Scholtz, J., & Unwin, J. (2020). What if Planet 9 is a Primordial Black Hole?. Physical Review Letters, 125(5), Article 051103. https://doi.org/10.1103/physrevlett.125.051103

• Journal Article Type: Article
• Acceptance Date: Jun 26, 2020
• Online Publication Date: Jul 29, 2020
• Publication Date: 2020-07
• Deposit Date: Aug 4, 2020
• Publicly Available Date: Aug 4, 2020
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 125
• Issue: 5
• Article Number: 051103
• DOI: https://doi.org/10.1103/physrevlett.125.051103