730 Athanasia

730 Athanasia (prov. designation: or ) is a background asteroid from the inner regions of the asteroid belt, approximately 4.5 km in diameter. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 10 April 1912. The presumed stony S-type asteroid has a rotation period of 5.7 hours and is likely very elongated in shape. It was named Athanasia, the Greek word for "immortality".

Orbit and classification
Located in the region of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt, Athanasia is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the inner asteroid belt at a distance of 1.8–2.6 AU once every 3 years and 4 months (1,228 days; semi-major axis of 2.24 AU). Its orbit has an eccentricity of 0.18 and an inclination of 4° with respect to the ecliptic. The body's observation arc begins at Vienna Observatory on 15 April 1912, or five nights after its official discovery observation.

Naming
This minor planet was named by friends of the discoverer after the Greek word for immortality, "athanasia". Any reference to a person or occurrence is unknown. The was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 73).

Physical characteristics
Athanasia is an assumed, stony S-type asteroid.

Rotation period
In February 2016, a rotational lightcurve of Athanasia was obtained from photometric observations by Frederick Pilcher at the Organ Mesa Observatory in New Mexico, United States. Analysis gave a classically shaped, well-defined bimodal lightcurve with a rotation period of $4.497 km$ hours and a very high brightness variation of $5.735 h$ magnitude, indicative of a highly elongated shape (U=3). In May 2013, Pilcher already observed the object and reported a ambiguous period of $0.289$ or $5.735$ hours with an amplitude of $0.63$ magnitude (U=2+).

Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Athanasia measures ($5.735$) kilometers in diameter and its surface has a high albedo of ($8.602$). The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a Florian asteroid of 0.24 and calculates a diameter of 4.94 kilometers based on an absolute magnitude of 13.7.