{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-01T20:31:20.111Z","years_from_j2000":26.668,"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-203-d","name":"Kepler-203 d","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2293.864327609411,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":297.089959,"dec_deg":41.3880686,"epoch_ra_deg":297.315734,"epoch_dec_deg":41.454339,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-203","semi_major_axis_km":14959787.07,"periapsis_km":null,"mass_kg":2.0245649071812776e+26,"mass_msun":0.000101818,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-203-d","radius_km":9184.464,"radius_kind":null,"data_quality":"The published mass and radius imply a density no material has. One of the two is likely an upper limit rather than a measurement.","description":null,"properties":{"host_star":"Kepler-203","host_v_mag":14.14,"eccentricity":0,"uncertainties":{"mass_kg":[1.982759732106738e+26,1.095295586952939e+27],"radius_km":[1785.8680000000002,1785.8680000000002],"distance_ly":[31.017471520862298,31.017471520862298],"host_mass_solar":[0.036,0.022],"host_radius_solar":[0.213,0.213],"host_temperature_k":[100,100],"orbital_period_days":[0.00008,0.00008]},"host_mass_solar":1.06,"inclination_deg":89.91,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.114,"planets_in_system":3,"discovery_facility":"Kepler","host_temperature_k":5821,"orbital_period_days":11.32972,"transit_midpoint_bjd":2454966.96882,"equilibrium_temperature_k":855},"designations":[{"catalog":"Exoplanet","designation":"Kepler-203 d"},{"catalog":"Host star","designation":"Kepler-203"}],"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":"2026-08-30T09:56:50.739Z","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."}