{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-02T22:54:42.847Z","years_from_j2000":26.671,"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-428-b","name":"Kepler-428 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2238.3590352495753,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":290.5817432,"dec_deg":40.5773106,"epoch_ra_deg":290.805208,"epoch_dec_deg":40.62798,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-428","semi_major_axis_km":6477587.801309999,"periapsis_km":null,"mass_kg":2.4105461164766345e+27,"mass_msun":0.0012123,"constellation":"Lyra","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-428-b","radius_km":77238.791,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-428","host_v_mag":15.362,"uncertainties":{"mass_kg":[3.606592175359214e+26,3.606592175359214e+26],"radius_km":[2168.554,2168.554],"distance_ly":[50.329190645470675,50.329190645470675],"host_mass_solar":[0.05,0.05],"inclination_deg":[0.43,0.43],"host_radius_solar":[0.02,0.02],"host_temperature_k":[100,100],"semi_major_axis_km":[134638.08362999998,134638.08362999998],"orbital_period_days":[1.5e-7,1.5e-7]},"host_mass_solar":0.87,"inclination_deg":89.36,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.8,"planets_in_system":1,"discovery_facility":"Kepler","host_spectral_type":"K1 V","host_temperature_k":5150,"orbital_period_days":3.52563254,"transit_midpoint_bjd":2455003.048008,"eccentricity_upper_limit":0.22,"equilibrium_temperature_k":1070},"designations":[{"catalog":"Exoplanet","designation":"Kepler-428 b"},{"catalog":"Host star","designation":"Kepler-428"}],"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."}