{"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":"2026-09-02T00:44:01.095Z","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-217-d","name":"Kepler-217 d","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":3602.853810810235,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":293.0377331,"dec_deg":46.2775223,"epoch_ra_deg":293.236922,"epoch_dec_deg":46.334129,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-217","semi_major_axis_km":7988526.29538,"periapsis_km":null,"mass_kg":1.3735986095920172e+25,"mass_msun":0.00000690803,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/kepler-217-d","radius_km":8419.092,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-217","host_v_mag":13.155,"eccentricity":0,"uncertainties":{"radius_km":[1722.0870000000002,2296.116],"distance_ly":[53.42441467000257,55.05519655858629],"host_mass_solar":[0.124,0.157],"host_radius_solar":[0.369,0.463],"host_temperature_k":[88.1,96.97],"semi_major_axis_km":[46375.339917,46375.339917],"orbital_period_days":[0.00002241,0.00002241]},"host_mass_solar":1.37,"inclination_deg":89.75,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.76,"planets_in_system":3,"discovery_facility":"Kepler","host_temperature_k":6341,"orbital_period_days":3.88689525,"transit_midpoint_bjd":2454965.49387,"equilibrium_temperature_k":1574},"designations":[{"catalog":"Exoplanet","designation":"Kepler-217 d"},{"catalog":"Host star","designation":"Kepler-217"}],"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":"2026-09-01T22:58:55.274Z","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."}