{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T18:56:03.058Z","years_from_j2000":26.67,"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-201-c","name":"Kepler-201 c","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2075.805958159328,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":293.626059,"dec_deg":41.2728004,"epoch_ra_deg":293.849048,"epoch_dec_deg":41.330865,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-201","semi_major_axis_km":85719579.91109999,"periapsis_km":null,"mass_kg":5.076342687622672e+25,"mass_msun":0.0000255297,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-201-c","radius_km":18177.585000000003,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-201","host_v_mag":12.991,"eccentricity":0,"uncertainties":{"radius_km":[3826.86,3826.86],"distance_ly":[30.945717117764612,31.875262794257335],"host_mass_solar":[0.03,0.029],"host_radius_solar":[0.24,0.24],"host_temperature_k":[117,117],"orbital_period_days":[0.002014,0.002014]},"host_mass_solar":1.098,"inclination_deg":89.27,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.229,"planets_in_system":2,"discovery_facility":"Kepler","host_temperature_k":6065,"orbital_period_days":151.884058,"transit_midpoint_bjd":2455009.41816,"equilibrium_temperature_k":378},"designations":[{"catalog":"Exoplanet","designation":"Kepler-201 c"}],"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":"2026-09-02T18:38:07.546Z","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."}