{"signature":{"source":"NASA/JPL Small-Body Database (SBDB) API","version":"1.3"},"orbit":{"rms":"0.27","not_valid_after":null,"first_obs":"1902-09-03","sb_used":"SB441-N16","pe_used":"DE441","epoch":"2461200.5","two_body":null,"source":"JPL","equinox":"J2000","moid":"2","n_obs_used":9585,"last_obs":"2026-01-01","t_jup":"3.166","cov_epoch":"2457315.5","model_pars":[],"data_arc":"45046","n_dop_obs_used":null,"not_valid_before":null,"soln_date":"2026-06-05 03:40:04","producer":"Otto Matic","orbit_id":"151","comment":null,"moid_jup":"1.66","n_del_obs_used":null,"elements":[{"units":null,"sigma":"1.9e-09","label":"e","title":"eccentricity","name":"e","value":"0.0491"},{"sigma":"3.3e-09","units":"au","label":"a","value":"3.15","title":"semi-major axis","name":"a"},{"name":"q","title":"perihelion distance","value":"3","units":"au","sigma":"4.1e-09","label":"q"},{"label":"i","sigma":"8.3e-08","units":"deg","value":"13","title":"inclination; angle with respect to x-y ecliptic plane","name":"i"},{"value":"167","title":"longitude of the ascending node","name":"om","label":"node","sigma":"4.3e-07","units":"deg"},{"name":"w","title":"argument of perihelion","value":"8.27","label":"peri","units":"deg","sigma":"1.8e-06"},{"label":"M","units":"deg","sigma":"1.7e-06","title":"mean anomaly","name":"ma","value":"200"},{"value":"2462106.229","name":"tp","title":"time of perihelion passage","sigma":"1e-05","units":"TDB","label":"tp"},{"name":"per","title":"sidereal orbital period","value":"2040","units":"d","sigma":"3.2e-06","label":"period"},{"title":"mean motion","name":"n","value":"0.176","units":"deg/d","sigma":"2.8e-10","label":"n"},{"value":"3.31","name":"ad","title":"aphelion distance","label":"Q","sigma":"3.5e-09","units":"au"}],"condition_code":"0"},"phys_par":[{"desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","ref":"E2025-UR3","value":"8.60","name":"H","notes":"IRAS observations used: 11","title":"absolute magnitude","sigma":null,"units":null},{"desc":"effective body diameter","name":"diameter","value":"139.39","ref":"IRAS-A-FPA-3-RDR-IMPS-V6.0","notes":"IRAS observations used: 11","title":"diameter","units":"km","sigma":"3.0"},{"units":"h","sigma":null,"title":"rotation period","notes":"REFERENCE LIST:[Weidenschilling, S.J.; Chapman, C.R.; Davis, D.R.; Greenberg, R.; et al. (1990) Icarus 86, 402-447.], [Stephens, R.D.; Brincat, S.M.; Koff, R.A. (2001) Minor Planet Bull. 28, 73.], [Durech, J. (2006) IAU 2006, poster paper.], [Hawkins, S.; Ditteon, R. (2008) Minor Planet Bull. 35, 1-4.], [Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.]","name":"rot_per","ref":"LCDB (Rev. 2023-October); Warner et al., 2009","value":"9.02","desc":"body rotation period (synodic)"},{"title":"geometric albedo","units":null,"sigma":"0.002","desc":"geometric albedo","name":"albedo","value":"0.0427","ref":"IRAS-A-FPA-3-RDR-IMPS-V6.0","notes":"IRAS observations used: 11"},{"notes":"#obs=2; phase (min.=6.74, mean=7.53, max.=8.32) deg.","desc":"color index B-V magnitude difference","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","value":"0.697","name":"BV","sigma":"0.016","units":null,"title":"B-V"},{"desc":"color index U-B magnitude difference","value":"0.369","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","name":"UB","notes":"#obs=2; phase (min.=6.74, mean=7.53, max.=8.32) deg.","title":"U-B","sigma":"0.045","units":null},{"notes":"used 2 color indices","name":"spec_T","ref":"EAR-A-5-DDR-TAXONOMY-V4.0","value":"C","desc":"Tholen spectral taxonomic classification","units":null,"sigma":null,"title":"Tholen spectral type"}],"object":{"shortname":"489 Comacina","des":"489","spkid":"20000489","neo":false,"fullname":"489 Comacina (A902 RD)","orbit_class":{"code":"MBA","name":"Main-belt Asteroid"},"pha":false,"prefix":null,"kind":"an","orbit_id":"151"}}