In the Tholen classification, Poësia is an uncommon F-type asteroid, though with an unusual spectrum,[4] while in the Barucci taxonomy, it is a carbonaceous C0-type.[6] The overall spectral type for members of the Themistian family is that of a C-type.[12]: 23
Rotation period
In January 2009, a rotational lightcurve of Poësia was obtained from photometric observations by Robert Stephens at the Santana Observatory (646) and Goat Mountain Astronomical Research Station (G79) in California. Lightcurve analysis gave an exceptionally long rotation period of 108.5±0.5 hours with a brightness amplitude of 0.32±0.05magnitude (U=2+).[11] A few weeks later, Gary A. Vander Haagen at Stonegate Observatory (H67) determined an ambiguous period of 73.5 or 102.9 hours with an amplitude of 0.24±0.05 magnitude (U=2),[13] while René Roy measured a tentative period of 48 hours (U=1).[14] With a best-rated period of 108.5 hours, Poësia is a slow rotator. While the slowest rotators have periods above 1000 hours, the vast majority of asteroids have periods between 2.2 and 20 hours.
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Poësia measures 36.210±0.149, 39.60±0.64 and 43.75±4.6 kilometers in diameter, and its surface has a corresponding albedo of 0.097±0.008, 0.079±0.003 and 0.0627±0.015, respectively.[7][8][9] The Collaborative Asteroid Lightcurve Link adopts the results from IRAS, that is, an albedo of 0.0627 and a diameter of 43.75 km based on an absolute magnitude of 9.8.[10]
Further published mean-diameters and albedos by the WISE team include 33.30±10.10 km, 35.84±11.06 km, 37.604±0.255 km and 38.990±0.248 km with albedos of 0.06±0.06, 0.06±0.04, 0.097±0.008 and 0.0789±0.0085, respectively.[6][10]
^ abcMasiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
^ abcUsui, 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)