(678191) 2017 OF69 is a resonant trans-Neptunian object from the Kuiper belt, located in the outermost region of the Solar System in the Kuiper belt's plutino population and measures approximately 533 kilometers (330 miles) in diameter. It was first observed on 26 July 2017, by American astronomers David Tholen, Scott Sheppard, and Chad Trujillo at Mauna Kea Observatories in Hawaii, but not announced until 31 May 2018 due to observations made in April and May 2018 refining its orbit significantly.[2]
2017 OF69 has not yet been imaged by high-resolution telescopes, so it has no known moons.[6] The Hubble Space Telescope is planned to image 2017 OF69 in 2026, which should determine if it has significantly sized moons.[6]
According to Johnston's Archive, 2017 OF69 measures 533 kilometers in diameter assuming an albedo of 0.09 for the body's surface.[5] This makes 2017 OF69 a notably large body for how late it has been discovered, being the fifth largest plutino in the Solar System, after Pluto, Orcus, Achlys, and Ixion, and the largest discovered since Orcus in 2004.
Rotation period
As of 2018, no rotational lightcurve of 2017 OF69 has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.[4]
References
12345"2017 OF69". Minor Planet Center. Retrieved 23 October 2018.
12"MPEC 2018-K109L 2017 OF69". Minor Planet Center. International Astronomical Union. 31 May 2018. Retrieved 1 June 2018.
12Proudfoot, Benjamin (August 2025). "A Search For The Moons of Mid-Sized TNOs". Mikulski Archive for Space Telescopes. Space Telescope Science Institute: HST Proposal 18010. Cycle 33. Retrieved 17 August 2025.
