{"signature":{"source":"NASA/JPL Small-Body Database (SBDB) API","version":"1.3"},"orbit":{"moid_jup":"0.248","elements":[{"value":"0.71","name":"e","label":"e","units":null,"title":"eccentricity","sigma":"5.3e-08"},{"name":"a","value":"3.5","title":"semi-major axis","sigma":"1.4e-07","units":"au","label":"a"},{"label":"q","units":"au","sigma":"2.1e-07","title":"perihelion distance","value":"1.01","name":"q"},{"name":"i","value":"32","sigma":"7.2e-06","title":"inclination; angle with respect to x-y ecliptic plane","label":"i","units":"deg"},{"sigma":"2.2e-05","title":"longitude of the ascending node","label":"node","units":"deg","name":"om","value":"195"},{"name":"w","value":"173","title":"argument of perihelion","sigma":"2.6e-05","units":"deg","label":"peri"},{"units":"deg","label":"M","title":"mean anomaly","sigma":"4.5e-06","value":"315","name":"ma"},{"value":"2458371.766","name":"tp","units":"TDB","label":"tp","title":"time of perihelion passage","sigma":"2.4e-05"},{"name":"per","value":"2390","title":"sidereal orbital period","sigma":"0.00014","units":"d","label":"period"},{"label":"n","units":"deg/d","title":"mean motion","sigma":"8.8e-09","value":"0.151","name":"n"},{"name":"ad","value":"5.99","sigma":"2.3e-07","title":"aphelion distance","label":"Q","units":"au"}],"sb_used":"SB441-N16","epoch":"2458070.5","producer":"Shantanu Naidu","n_del_obs_used":null,"moid":"0.0178","model_pars":[{"name":"A1","value":"3.468e-09","n":1,"sigma":"5.407E-11","title":"non-grav. radial accel.","units":"au/d^2","desc":"non-gravitational radial acceleration parameter","kind":"EST"},{"name":"A2","value":"-1.542e-09","n":2,"title":"non-grav. transverse accel.","sigma":"2.902E-12","desc":"non-gravitational transverse acceleration parameter","units":"au/d^2","kind":"EST"},{"n":3,"title":"non-grav. normal accel.","sigma":"3.868E-11","units":"au/d^2","desc":"non-gravitational normal acceleration parameter","kind":"EST","name":"A3","value":"-1.952e-09"}],"rms":"0.52","cov_epoch":"2458070.5","not_valid_before":null,"soln_date":"2025-11-23 22:20:59","orbit_id":"K253/4","n_obs_used":1993,"last_obs":"2024-10-21","two_body":null,"not_valid_after":null,"condition_code":"0","first_obs":"2011-05-01","comment":null,"source":"JPL","data_arc":"4922","equinox":"J2000","n_dop_obs_used":null,"pe_used":"DE441","t_jup":"2.465"},"object":{"fullname":"21P/Giacobini-Zinner","kind":"cn","des":"21P","pha":false,"orbit_class":{"code":"JFc","name":"Jupiter-family Comet"},"orbit_id":"K253/4","neo":true,"spkid":"1000032","prefix":"P"},"phys_par":[{"title":"comet total magnitude","sigma":"0.8","notes":"2 parameter fit from 638 observations, autocmod 3.0g","units":null,"desc":"absolute magnitude of comet and coma (i.e. total)","name":"M1","ref":"K253/4","value":"13.2"},{"ref":"K253/4","name":"K1","value":"8.25","title":"comet total magnitude slope","sigma":null,"desc":"comet total magnitude slope parameter","units":null,"notes":"autocmod 3.0g"},{"desc":"effective body diameter","units":"km","notes":null,"sigma":null,"title":"diameter","value":"2.0","ref":"Lamy,P.L.,Toth,I.,Fernandez,Y.R.,Weaver,H.A. (2004) Comets II, pp. 223-264","name":"diameter"}]}