{"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":"2026-09-02T17:02:33.699Z","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-220-c","name":"Kepler-220 c","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":558.0829163473426,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":291.5060432,"dec_deg":46.8956262,"epoch_ra_deg":291.700526,"epoch_dec_deg":46.948519,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-220","semi_major_axis_km":11369438.173199998,"periapsis_km":null,"mass_kg":1.845399871147536e+25,"mass_msun":0.00000928078,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-220-c","radius_km":10013.617,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-220","host_v_mag":13.049,"eccentricity":0,"uncertainties":{"radius_km":[574.029,574.029],"distance_ly":[2.0645698709469857,2.0776161260556556],"host_mass_solar":[0.0185,0.0185],"host_radius_solar":[0.034,0.034],"host_temperature_k":[100,100],"orbital_period_days":[0.000009,0.000009]},"host_mass_solar":0.729,"inclination_deg":88.12,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.666,"planets_in_system":4,"discovery_facility":"Kepler","host_temperature_k":4632,"orbital_period_days":9.034199,"transit_midpoint_bjd":2455004.01425,"equilibrium_temperature_k":586},"designations":[{"catalog":"Exoplanet","designation":"Kepler-220 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":"2026-09-01T22:58:55.274Z","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."}