{"object":{"shortname":"24 Themis","fullname":"24 Themis (A853 GA)","des":"24","orbit_id":"154","pha":false,"orbit_class":{"name":"Main-belt Asteroid","code":"MBA"},"neo":false,"kind":"an","prefix":null,"spkid":"20000024"},"signature":{"version":"1.3","source":"NASA/JPL Small-Body Database (SBDB) API"},"orbit":{"condition_code":"0","not_valid_after":null,"soln_date":"2026-06-05 03:03:25","two_body":null,"n_del_obs_used":null,"producer":"Otto Matic","comment":null,"rms":"0.45","cov_epoch":"2458194.5","t_jup":"3.199","n_dop_obs_used":null,"n_obs_used":6577,"last_obs":"2026-04-04","pe_used":"DE441","elements":[{"sigma":"2.1e-09","name":"e","label":"e","units":null,"value":"0.115","title":"eccentricity"},{"value":"3.14","title":"semi-major axis","label":"a","units":"au","name":"a","sigma":"3.4e-09"},{"label":"q","units":"au","sigma":"7.8e-09","name":"q","title":"perihelion distance","value":"2.78"},{"name":"i","sigma":"1.5e-07","units":"deg","label":"i","title":"inclination; angle with respect to x-y ecliptic plane","value":"0.737"},{"label":"node","units":"deg","name":"om","sigma":"1.1e-05","title":"longitude of the ascending node","value":"36.4"},{"value":"109","title":"argument of perihelion","units":"deg","label":"peri","name":"w","sigma":"1.1e-05"},{"sigma":"9.7e-07","name":"ma","units":"deg","label":"M","title":"mean anomaly","value":"92"},{"value":"2460680.040","title":"time of perihelion passage","name":"tp","sigma":"5.4e-06","units":"TDB","label":"tp"},{"sigma":"3.3e-06","name":"per","units":"d","label":"period","value":"2040","title":"sidereal orbital period"},{"value":"0.177","title":"mean motion","units":"deg/d","label":"n","sigma":"2.9e-10","name":"n"},{"label":"Q","units":"au","name":"ad","sigma":"3.8e-09","value":"3.51","title":"aphelion distance"}],"sb_used":"SB441-N16","data_arc":"63164","orbit_id":"154","moid":"1.79","source":"JPL","first_obs":"1853-04-27","model_pars":[],"equinox":"J2000","epoch":"2461200.5","not_valid_before":null,"moid_jup":"1.51"},"phys_par":[{"ref":"MPO980521","notes":null,"value":"7.21","desc":"absolute magnitude (magnitude at 1 au from Sun and observer)","title":"absolute magnitude","name":"H","sigma":null,"units":null},{"name":"G","sigma":null,"units":null,"title":"magnitude slope","notes":"Fit","desc":"magnitude slope parameter used in the standard asteroid H/G magnitude law","value":"0.19","ref":"PDS3 (MPC 17257)"},{"ref":"J.G. Williams (E-mail September 1990)","value":"198","notes":"based on IRTF albedo of 0.067","title":"diameter","desc":"effective body diameter","name":"diameter","sigma":null,"units":"km"},{"name":"rot_per","sigma":null,"units":"h","ref":"LCDB (Rev. 2023-October); Warner et al., 2009","title":"rotation period","notes":"REFERENCE LIST:[Tedesco, E.F. (1979) PhD Dissertation, New. Mex. State Univ. 280pp.], [Van Houten-Groeneveld, I.; van Houten, C.J.; Zappala, V. (1979) Astron. Astrophys. Suppl. Ser. 35, 223-232.], [Harris, A.W.; Young, J.W. (1983) Icarus 54, 59-109.], [Harris, A.W.; Young, J.W.; Bowell, E.; Martin, L.J.; et al. (1989) Icarus 77, 171-186.], [Chiorny, V.G.; Shevchenko, V.G.; Krugly, Yu.N.; Velichko, F.P.; Gaftonyuk, N.M. (2007) Planet. Space Sci. 55, 986-997.], [Ditteon, R.; Hawkins, S. (2007) Minor Planet Bull. 34, 59-64.], [Higley, S.; Hardersen, P.; Dyvig, R. (2008) Minor Planet Bull. 35, 63-66.], [Pilcher, F. (2012) http://aslc-nm.org/Pilcher.html], [Pilcher, F. (2013) Minor Planet Bull. 40, 85-87.], [Pilcher, F. (2014) Minor Planet Bull. 41, 250-252.], [Hanus, J.; Durech, J.; Oszkiewicz, D.A.; Behrend, R.; et al. (2016) Astron. Astrophys. 586, A108.], [Behrend, R. (2017) Observatoire de Geneve web site, http://obswww.unige.ch/~behrend/page_cou.html], [Viikinkoski, M.; Hanus, J.; Kaasalainen, M.; Marchis, F.; Durech, J. (2017) Astron. Astrophys. 607, A117.], [Vernazza, P.; Ferrais, M.; Jorda, L.; Hanus, J.; et al. (2021) Astron. Astrophys 654, id. A56.], [Ferrais, M.; Vernazza, P.; Jorda, L.; Jehin, E.; et al. (2022) Minor Planet Bull. 49, 307-313.]","value":"8.374","desc":"body rotation period (synodic)"},{"sigma":null,"name":"albedo","units":null,"ref":"J.G. Williams (E-mail September 1990)","value":"0.067","notes":"IRTF","title":"geometric albedo","desc":"geometric albedo"},{"name":"BV","sigma":"0.030","units":null,"ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","notes":"#obs=10; phase (min.=.16, mean=9.29, max.=18.36) deg.","title":"B-V","desc":"color index B-V magnitude difference","value":"0.684"},{"value":"0.336","notes":"#obs=8; phase (min.=.16, mean=8.75, max.=18.36) deg.","desc":"color index U-B magnitude difference","title":"U-B","ref":"EAR-A-5-DDR-UBV-MEAN-VALUES-V1.2","units":null,"sigma":"0.024","name":"UB"},{"ref":"EAR-A-5-DDR-TAXONOMY-V4.0","notes":"used 7 color indices; used ground-based radiometric albedo","title":"Tholen spectral type","desc":"Tholen spectral taxonomic classification","value":"C","units":null,"sigma":null,"name":"spec_T"},{"ref":"EAR-A-5-DDR-TAXONOMY-V4.0","notes":"based on a high-resolution spectrum by Xu et al. (1995) or Bus and Binzel (2002)","desc":"SMASSII spectral taxonomic classification","title":"SMASSII spectral type","value":"B","sigma":null,"name":"spec_B","units":null}]}