2020 BX<sub>12</sub>—The Last Binary Asteroid Discovered at Arecibo
Abstract Radar observations of 2020 BX 12 conducted with the S -band planetary radar system (2380 MHz, 12.6 cm) at the Arecibo Observatory on 2020 February 4 and 5 revealed that this potentially hazardous asteroid is a binary system. Spectroscopic observations with the 10.4 m Gran Telescopio Canarias on 2024 February 16 indicate that 2020 BX 12 is an S-complex asteroid (Bus–DeMeo taxonomy). We present the results of shape modeling and orbit fitting based on the radar observations. The system consists of a primary of a diameter ∼205 m and a ∼50 m secondary revolving around their common center of mass. This size places the system among the smallest 10% of known binary asteroid systems. The orbital period of the system is >40 hr. The semimajor axis is >375 m. This binary system, like many other binary near-Earth asteroids, features a spheroidal primary spinning near the breakup point, indicating likely formation through spin-up and fission and migration from the main belt. 2020 BX 12 was the last binary asteroid discovered at Arecibo.
Authors
- S. Marshall (ORCID: https://orcid.org/0000-0002-8144-7570)
- N. Pinilla-Alonso (ORCID: https://orcid.org/0000-0002-2770-7896)
- Flaviane Venditti (ORCID: https://orcid.org/0000-0001-9150-8376)
- E. S. Howell (ORCID: https://orcid.org/0000-0002-7683-5843)
- Jon D. Giorgini (ORCID: https://orcid.org/0000-0002-7062-0091)
- Luisa Fernanda Zambrano-Marin (ORCID: https://orcid.org/0000-0002-6615-4040)
- J. de León (ORCID: https://orcid.org/0000-0002-0696-0411)
- Anne Virkki (ORCID: https://orcid.org/0000-0002-4129-5381)
Institutions
- University of Central Florida (US)
- Jet Propulsion Laboratory (US)
- University of Helsinki (FI)
- University of Arizona (US)
- Universidad de Oviedo (ES)
- Universidad de Granada (ES)
- Helsinki Institute of Physics (FI)
- Instituto de Astrofísica de Canarias (ES)
- Instituto Nacional de Silicosis (ES)
Publication Details
- Journal
- The Planetary Science Journal
- Published
- 2025-04-01
- DOI
- https://doi.org/10.3847/psj/adbe39
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- California Institute of Technology
- University of Central Florida
- Nuclear Safety and Security Commission
- Universidad de Granada
- Jet Propulsion Laboratory