216433 Milianleo

216433 Milianleo is an Aeolia asteroid from the central region of the asteroid belt, approximately in diameter. It was discovered 19 February 2009, by German amateur astronomer Erwin Schwab using a remote-controlled telescope at Tzec Maun Observatory in Mayhill, New Mexico, United States. The asteroid was named after the discoverer's son, Milian Leo Schwab.

Orbit and classification

Milianleo is an attributed member of the Aeolia family, a small asteroid family that has fewer than 300 known members. The family is named after its parent body and largest member, 396 Aeolia. Milianleo orbits the Sun in the central main asteroid belt at a distance of 2.4–3.1 Astronomical units, completing its orbit once every 4 years and 6 months. It has an eccentricity of 0.13 and an inclination of 3° with respect to the ecliptic. It was first observed as at Lincoln Laboratory ETS in 2000, extending the body's observation arc by 9 years prior to its official discovery at Tzec Maun.
On 25 December 2098, Milianleo is expected to pass 4,449,642 kilometers from the asteroid 704 Interamnia. It will pass it at a relative velocity of 7.12 kilometers per second.

Milianleo is likely an X-type asteroid, based on its membership to the Aeolia family. When using a generic magnitude-to-diameter conversion, it measures approximately 1.6 kilometers in diameter when using an absolute magnitude of 16.5 and an assumed visual geometric albedo of 0.17—these values are derived from the Aeolia family's parent body. As of 2018, no rotational lightcurve of Milianleo has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.

This minor planet was named after Milian Leo Schwab, the first-born son of German amateur astronomer and discoverer Erwin Schwab. The naming approval citation was published by the Minor Planet Center on 4 October 2009.