{"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":"2026-09-01T23:42:40.240Z","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-30-c","name":"Kepler-30 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2981.790097925789,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":285.2836483,"dec_deg":38.9472625,"epoch_ra_deg":285.510598,"epoch_dec_deg":38.984719,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-30","semi_major_axis_km":44879361.20999999,"periapsis_km":null,"mass_kg":3.8221874353864827e+27,"mass_msun":0.00192223,"constellation":"Lyra","discovered":"2012","featured":false,"url":"https://spacecatalog.org/object/kepler-30-c","radius_km":78450.63,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-30","host_v_mag":15.726,"eccentricity":0.0111,"uncertainties":{"mass_kg":[2.9860839338956895e+26,2.9860839338956895e+26],"radius_km":[2551.2400000000002,2551.2400000000002],"distance_ly":[88.32803943135987,88.32803943135987],"eccentricity":[0.001,0.001],"host_mass_solar":[0.08,0.08],"inclination_deg":[0.0302,0.0302],"host_radius_solar":[0.12,0.12],"host_temperature_k":[54,54],"orbital_period_days":[0.000244,0.000244],"argument_of_periastron_deg":[6,6]},"host_mass_solar":0.99,"inclination_deg":90.3227,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.95,"planets_in_system":3,"discovery_facility":"Kepler","host_temperature_k":5498,"orbital_period_days":60.323105,"transit_midpoint_bjd":2455357.887042,"equilibrium_temperature_k":411,"argument_of_periastron_deg":-49},"designations":[{"catalog":"Exoplanet","designation":"Kepler-30 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."}