{"orbit":{"soln_date":"2026-06-05 03:44:20","elements":[{"label":"e","name":"e","units":null,"sigma":"1.9e-09","title":"eccentricity","value":"0.175"},{"title":"semi-major axis","sigma":"4.1e-09","units":"au","value":"3.2","label":"a","name":"a"},{"label":"q","name":"q","title":"perihelion distance","units":"au","sigma":"4.3e-09","value":"2.64"},{"label":"i","name":"i","value":"11.3","title":"inclination; angle with respect to x-y ecliptic plane","units":"deg","sigma":"8e-08"},{"label":"node","name":"om","title":"longitude of the ascending node","sigma":"4.7e-07","units":"deg","value":"333"},{"label":"peri","name":"w","title":"argument of perihelion","units":"deg","sigma":"6.3e-07","value":"334"},{"units":"deg","sigma":"1.1e-06","title":"mean anomaly","value":"202","label":"M","name":"ma"},{"label":"tp","name":"tp","value":"2462120.363","title":"time of perihelion passage","sigma":"8.3e-06","units":"TDB"},{"name":"per","label":"period","title":"sidereal orbital period","units":"d","sigma":"4e-06","value":"2090"},{"name":"n","label":"n","title":"mean motion","units":"deg/d","sigma":"3.3e-10","value":"0.172"},{"value":"3.76","title":"aphelion distance","units":"au","sigma":"4.8e-09","label":"Q","name":"ad"}],"moid":"1.63","epoch":"2461200.5","model_pars":[],"data_arc":"44386","not_valid_before":null,"n_dop_obs_used":null,"two_body":null,"producer":"Otto Matic","cov_epoch":"2457576.5","comment":null,"orbit_id":"89","pe_used":"DE441","n_del_obs_used":null,"condition_code":"0","sb_used":"SB441-N16","source":"JPL","t_jup":"3.140","n_obs_used":7259,"first_obs":"1904-10-03","moid_jup":"1.56","rms":"0.31","last_obs":"2026-04-12","equinox":"J2000","not_valid_after":null},"phys_par":[{"sigma":null,"units":null,"title":"absolute magnitude","ref":"E2026L10","value":"8.79","notes":"IRAS observations used: 11","desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","name":"H"},{"sigma":"1.223","units":"km","title":"diameter","ref":"urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)","value":"112.631","notes":null,"desc":"effective body diameter","name":"diameter"},{"desc":"body rotation period (synodic)","name":"rot_per","sigma":null,"units":"h","title":"rotation period","ref":"LCDB (Rev. 2023-October); Warner et al., 2009","value":"7.2","notes":"REFERENCE LIST:[Di Martino, M. (1984) Icarus 60, 541-546.], [Weidenschilling, S.J.; Chapman, C.R.; Davis, D.R.; Greenberg, R.; et al. (1990) Icarus 86, 402-447.], [Behrend, R. (2006) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Durech, J.; Tonry, J.; Erasmus, N.; Denneau, L.; et al. (2020) Astron. Astrophys. 643, A59.]"},{"value":"0.041","notes":null,"sigma":"0.005","units":null,"title":"geometric albedo","ref":"urn:nasa:pds:neowise_diameters_albedos::2.0[mainbelt] (http://adsabs.harvard.edu/abs/2014ApJ...791..121M)","desc":"geometric albedo","name":"albedo"},{"value":"0.686","notes":"#obs=2; phase (min.=13.94, mean=14.07, max.=14.21) deg.","units":null,"sigma":"0.038","title":"B-V","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","desc":"color index B-V magnitude difference","name":"BV"},{"notes":"#obs=1; phase=13.94 deg.","value":"0.343","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","title":"U-B","sigma":"0.058","units":null,"name":"UB","desc":"color index U-B magnitude difference"},{"name":"spec_T","desc":"Tholen spectral taxonomic classification","notes":"used 2 color indices","value":"CD","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","title":"Tholen spectral type","sigma":null,"units":null},{"sigma":null,"units":null,"title":"SMASSII spectral type","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"Cb","notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","desc":"SMASSII spectral taxonomic classification","name":"spec_B"}],"object":{"prefix":null,"pha":false,"fullname":"545 Messalina (A904 TC)","shortname":"545 Messalina","orbit_id":"89","des":"545","spkid":"20000545","orbit_class":{"name":"Outer Main-belt Asteroid","code":"OMB"},"neo":false,"kind":"an"},"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"}}