It orbits the Sun in the inner asteroid belt at a distance of 2.1–2.8 AU once every 3 years and 11 months (1,426 days; semi-major axis of 2.48 AU). Its orbit has an eccentricity of 0.13 and an inclination of 4° with respect to the ecliptic.[5]
The body's observation arc begins with its first observation as A907 VQ at Heidelberg in November 1907, more than 16 years prior to its official discovery observation.[1]
In April 1983, a first rotational lightcurve of Sarema was obtained from photometric observations by American astronomer Richard Binzel. Lightcurve analysis gave a well-defined rotation period of 10.32 hours with a brightness amplitude of 0.81 magnitude (U=3), which is indicative for an elongated, non-spherical shape.[15]
In 2009 and 2011, two modeled lightcurves gave a concurring sidereal period 10.30708 hours, combining sparse and dense photometric data from the Uppsala Asteroid Photometric Catalogue and other sources. The two studies also determined two spin axis of (45.0°, 67.0°) and (253.0°, 63.0°), as well as (51.0°, 64.0°) and (254.0°, 53.0°) in ecliptic coordinates (λ, β), respectively.[13][14]
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Sarema measures between 16.06 and 22.96 kilometers in diameter and its surface has an albedo between 0.0342 and 0.07.[6][7][8][9][10][11][12] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.045 and a diameter of 21.13 kilometers based on an absolute magnitude of 12.36.[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)
^ abHanus, J.; Durech, J.; Broz, M.; Warner, B. D.; Pilcher, F.; Stephens, R.; et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy and Astrophysics. 530: 16. arXiv:1104.4114. Bibcode:2011A&A...530A.134H. doi:10.1051/0004-6361/201116738.