{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.689","julian_year":2026.689,"time":"2026-09-09T19:12:07.907Z","years_from_j2000":26.689,"frame":"date","applied":"Proper motion, then precession and nutation. The catalogued J2000 position is carried along the great circle the object's own published motion puts it on, at a constant velocity, and the result is referred to the true equator and equinox of this instant. Those are separate things: the motion moves the object, and the rotation turns the grid under it by about fifty arcseconds a year, with nutation adding up to another seventeen.","excluded":"Parallax, the radial-velocity perspective term, aberration and refraction; each is below the accuracy of the catalogued positions themselves. An object with no published proper motion comes back where the catalogue has it rather than at a fabricated zero, and says so with a null pm_ra_mas_yr. A body with no fixed position is not propagated at all — its place comes from an ephemeris, which is what /api/v1/visible answers with."},"slug":"11-umi-b","name":"11 UMi b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":408.7424341184,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":229.2745954,"dec_deg":71.8239428,"epoch_ra_deg":229.279197,"epoch_dec_deg":71.724569,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"11 UMi","semi_major_axis_km":228884742.17099997,"periapsis_km":null,"mass_kg":2.7978496831812774e+28,"mass_msun":0.0140708,"constellation":"Ursa Minor","discovered":"2009","featured":false,"url":"https://spacecatalog.org/object/11-umi-b","radius_km":78450.63,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"11 UMi","host_v_mag":5.013,"eccentricity":0.08,"uncertainties":{"mass_kg":[4.745335283550335e+27,4.745335283550335e+27],"distance_ly":[6.446480805571434,6.446480805571434],"eccentricity":[0.03,0.03],"host_mass_solar":[0.69,0.69],"host_radius_solar":[2.84,2.84],"host_temperature_k":[46,46],"semi_major_axis_km":[10471850.949000001,10471850.949000001],"orbital_period_days":[3.2,3.2],"argument_of_periastron_deg":[21.06,21.06]},"host_mass_solar":2.78,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":29.79,"planets_in_system":1,"discovery_facility":"Thueringer Landessternwarte Tautenburg","host_spectral_type":"K4 III","host_temperature_k":4213,"orbital_period_days":516.21997,"periastron_epoch_bjd":2452861.04,"equilibrium_temperature_k":896.43,"argument_of_periastron_deg":117.63},"designations":[{"catalog":"Exoplanet","designation":"11 UMi b"},{"catalog":"Host star","designation":"11 UMi"}],"source":{"id":"exoplanet_archive","name":"NASA Exoplanet Archive (Planetary Systems Composite Parameters)","url":"https://exoplanetarchive.ipac.caltech.edu/cgi-bin/TblView/nph-tblView?app=ExoTbls&config=PSCompPars","license":"Public domain (NASA)"},"updated_at":"2026-09-09T11:17:28.634Z","attribution":"Data from SpaceCatalog.org. Individual records carry their source and license in `source`; attribution is required for CC-BY and CC-BY-SA rows."}