(315530) 2008 AP129
A trans-Neptunian object possibly belonging to the Haumea family.
Wikipedia / Wikimedia Commons
(315530) 2008 AP129 is a trans-Neptunian object, likely a cubewano, located in the outer Solar System. Its diameter is estimated at about 480 kilometers. The object was discovered on January 11, 2008, by American astronomers Michael E. Brown and Megan Schwamb using the Palomar Observatory in California. It orbits the Sun at distances ranging from 35.8 to 47.5 AU, completing one revolution every 267 years and 11 months (98,249 days), with a semi-major axis of 41.70 AU. Its orbit has an eccentricity of 0.14 and an inclination of 27° relative to the ecliptic. Precovery observations date back to 1989. Lightcurve analysis suggests a rotation period of 9.04 hours, though this is uncertain, with a brightness variation of 0.12 magnitude. A 2019 dynamical study by Proudfoot and Ragozzine identified it as a member of the Haumea family, implying it may be a collisional fragment from the dwarf planet Haumea. This classification is supported by the neutral color of its visible spectrum, indicating a lack of complex organic compounds on its surface, and by common infrared water-ice absorption patterns shared with other Haumea family members. The Minor Planet Center assigned its number on February 7, 2012, but as of 2025, it remains unnamed.
- discovered
- 11 January 2008
- diameter
- approximately 480 kilometers
- orbit_period
- 267 years and 11 months
- semi-major_axis
- 41.70 AU
- eccentricity
- 0.14
- inclination
- 27°
- rotation_period
- 9.04 hours (ambiguous)
Lore & Background
2008 AP129 orbits the Sun at a distance of 35.8–47.5 AU once every 267 years and 11 months, with a semi-major axis of 41.70 AU. Its orbit has an eccentricity of 0.14 and an inclination of 27° with respect to the ecliptic. It has three precovery observations dating back to 1989. Lightcurve analysis gave an ambiguous rotation period of 9.04 hours with a brightness amplitude of 0.12 magnitude.
Reader's Guide
2008 AP129 is significant as a possible cubewano and a member of the Haumea family, identified in a 2019 dynamical study by Proudfoot and Ragozzine. Its neutral color in the visible spectrum indicates a lack of complex organics on its surface, consistent with other collisional fragments of Haumea. The object was numbered by the Minor Planet Center on 7 February 2012 but, as of 2025, has not been named. Its study helps understand the collisional history of the outer Solar System and the composition of Haumea's family.
Did You Know?
- 2008 AP129 was discovered on 11 January 2008 by Michael E. Brown and Megan Schwamb at Palomar Observatory.
- It has an ambiguous rotation period of 9.04 hours from lightcurve analysis.
- The object is approximately 480 kilometers in diameter.
- It was identified as a member of the Haumea family in a 2019 dynamical study.
More in Discoveries by Michael E. Brown 1-24
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