(523692) 2014 EZ51
A rapidly rotating trans-Neptunian object in the scattered disc.
(523692) 2014 EZ51 is a large object in the scattered disc beyond Neptune, with a diameter estimated between 575 and 1,300 kilometers. It spins very quickly, completing one rotation every 3.2 hours—faster than the dwarf planet Haumea. Its orbit takes it from 40.7 to 64.4 AU from the Sun, with a period of about 380.5 years, and it is locked in a 9:4 orbital resonance with Neptune.
The object was first observed on 18 April 2010 by the Pan-STARRS 1 survey at Haleakala Observatory in Hawaii, though it was officially discovered on 28 April 2014 by the DECam in Chile. Precovery images from 2010 helped confirm its orbit. It was assigned a minor planet number on 25 September 2018, but as of early 2026, it has not been given a name.
A stellar occultation by 2014 EZ51 was observed in New Zealand on 25 February 2019. Those observations set a lower limit on its mean diameter of 575 kilometers, while another analysis of the same event suggested an equatorial diameter of at least 1,260 kilometers. If the larger size is correct, its geometric albedo must be less than 0.03. Astronomer Michael Brown, using an older absolute magnitude of 4.1 and an assumed albedo of 0.11, estimated a diameter of 626 kilometers.
In 2023, photometric data from the Kepler space telescope revealed that 2014 EZ51 rotates once every 3.200 ± 0.002 hours, with a light curve amplitude of 0.145 ± 0.026 magnitudes, indicating an elongated shape. No moons have been detected, and the object has not been imaged by high-resolution telescopes. The Hubble Space Telescope is scheduled to observe it in 2026, which should reveal whether it has any sizable satellites.
Quick Facts
- Minorplanet
- yes
- Discoverer
- Pan-STARRS 1
- Discovery Site
- Haleakala Obs.
- Discovered
- 18 April 2010
- Mpc Name
- (523692) 2014 EZ · 51
- Mp Category
- TNOSDOdistant
- Epoch
- 5 May 2025 (JD 2460800.5)
- Uncertainty
- 22
- Observation Arc
- 14.22 yr (5,193 d)
- Perihelion
- 39.972 AU
- Semimajor
- 51.852 AU
- Eccentricity
- 0.2291
Facts from the source article.
Lore & Background
2014 EZ51 was discovered on 28 April 2014 by the DECam at Coquimbo Region, Chile, with precovery observations back to 18 April 2010 by the Pan-STARRS 1 survey at Haleakala Observatory, Hawaii. It orbits the Sun at a distance of 40.7–64.4 AU once every 380.5 years, with an eccentricity of 0.23 and an inclination of 10° relative to the ecliptic. The object is in a 9:4 resonance with Neptune, meaning it completes four orbits for every nine of Neptune's.
Its physical characteristics are partly uncertain. A stellar occultation on 25 February 2019 in New Zealand placed a lower limit of 575 km on its mean diameter, while another analysis of the same event suggested an equatorial diameter of at least 1,260 km, implying a geometric albedo below 0.03. Photometric observations by the Kepler space telescope in 2023 determined a rotation period of 3.200±0.002 hours with a light curve amplitude of 0.145±0.026 magnitudes, indicating an elongated shape. The object has not yet been imaged by high-resolution telescopes and has no known moons; the Hubble Space Telescope is planned to image it in 2026 to search for significantly sized moons.
Reader's Guide
2014 EZ51 is significant as a large scattered-disc object with a notably short rotation period, shorter than that of the dwarf planet Haumea. Its size remains uncertain, with estimates ranging from 575 km to over 1,260 km depending on the interpretation of occultation data and assumed albedo. The object's 9:4 orbital resonance with Neptune places it among a class of trans-Neptunian objects whose orbits are shaped by Neptune's gravitational influence. Its rapid rotation and elongated shape, inferred from light-curve observations, suggest it may be a contact binary or a highly irregular body. The planned Hubble Space Telescope imaging in 2026 could resolve its shape and detect any moons, providing further insight into its formation and evolution. As of January 2026, it has not been named, and its numbering by the Minor Planet Center occurred on 25 September 2018.
Did You Know?
- 2014 EZ51 has a rotation period of 3.2 hours, shorter than Haumea's 3.92 hours.
- It was discovered by the DECam in Chile on 28 April 2014, with precovery images from 2010.
- A stellar occultation in New Zealand on 25 February 2019 gave a lower diameter limit of 575 km.
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