It orbits the Sun in the inner main-belt at a distance of 1.9–2.5 AU once every 3 years and 4 months (1,208 days). Its orbit has an eccentricity of 0.13 and an inclination of 2° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Heidelberg in January 1925.[14]
Physical characteristics
The LCDB assumes it to be a stony S-type asteroid, due to its dynamical classification as a member of the Flora family (402).[3]
Rotation period
Two rotational lightcurve of Gerti were obtained from photometric observations by Wiesław Wiśniewski in February 1988, and by astronomers at the Palomar Transient Factory in January 2011, respectively. Lightcurve analysis gave an identical rotation period of 3.082 hours with a respective brightness amplitude of 0.20 and 0.29 magnitude (U=3/2).[10][11] A third lightcurve by René Roy in March 2008 gave a period of 3.0 hours with an amplitude of 0.36 magnitude (U=2).[8]
Poles
In 2011, a modeled lightcurve using data from the Uppsala Asteroid Photometric Catalogue and other sources gave a concurring sidereal period of 3.081545 hours, as well as two spin axis of (268.0°, 23.0°) and (87.0°, 28.0°) in ecliptic coordinates (λ, β).[9]
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – taken from 8 Flora, the Flora family's parent body – and derives a diameter of 8.54 kilometers based on an absolute magnitude of 12.51.[3]
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)