{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.676","julian_year":2026.676,"time":"2026-09-04T19:38:38.278Z","years_from_j2000":26.676,"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-393-c","name":"Kepler-393 c","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2874.7553594504852,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":290.995205,"dec_deg":45.192188,"epoch_ra_deg":291.197927,"epoch_dec_deg":45.243871,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-393","semi_major_axis_km":18550135.966799997,"periapsis_km":null,"mass_kg":1.3915151131953915e+25,"mass_msun":0.00000699813,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-393-c","radius_km":8482.873000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-393","host_v_mag":13.258,"eccentricity":0,"uncertainties":{"radius_km":[1977.211,1977.211],"distance_ly":[44.350744241922776,45.73364728344176],"host_mass_solar":[0.021,0.023],"host_radius_solar":[0.263,0.263],"host_temperature_k":[100,100],"orbital_period_days":[0.000231,0.000231]},"host_mass_solar":1.256,"inclination_deg":89.77,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.382,"planets_in_system":2,"discovery_facility":"Kepler","host_temperature_k":6189,"orbital_period_days":14.613612,"transit_midpoint_bjd":2454973.4124,"equilibrium_temperature_k":901},"designations":[{"catalog":"Exoplanet","designation":"Kepler-393 c"},{"catalog":"Host star","designation":"Kepler-393"}],"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."}