{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T09:03:11.921Z","years_from_j2000":26.675,"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":"kepler-1121-b","name":"Kepler-1121 b","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1572.2270340922303,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":297.7865467,"dec_deg":47.8861542,"epoch_ra_deg":297.983097,"epoch_dec_deg":47.954054,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-1121","semi_major_axis_km":17679476.359325998,"periapsis_km":null,"mass_kg":2.574004351018084e+25,"mass_msun":0.000012945,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/kepler-1121-b","radius_km":12182.171,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-1121","host_v_mag":12.144,"eccentricity":0,"uncertainties":{"radius_km":[2933.9260000000004,3061.4880000000003],"distance_ly":[14.28891090777053,14.546574446166757],"host_mass_solar":[0.091,0.13],"host_radius_solar":[0.293,0.397],"host_temperature_k":[72.86,90.24],"semi_major_axis_km":[79286.87147099999,79286.87147099999],"orbital_period_days":[0.00005864,0.00005864]},"host_mass_solar":1.29,"inclination_deg":84.73,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.59,"planets_in_system":1,"discovery_facility":"Kepler","host_temperature_k":6231,"orbital_period_days":13.15141081,"transit_midpoint_bjd":2454977.16108,"equilibrium_temperature_k":1008},"designations":[{"catalog":"Exoplanet","designation":"Kepler-1121 b"},{"catalog":"Host star","designation":"Kepler-1121"}],"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":"2026-09-02T19:50:56.720Z","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."}