{"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":"2026-09-02T03:31:18.627Z","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-17-b","name":"Kepler-17 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2350.78187708476,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":298.3952437,"dec_deg":47.8149865,"epoch_ra_deg":298.592901,"epoch_dec_deg":47.884264,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-17","semi_major_axis_km":3876080.8298369995,"periapsis_km":null,"mass_kg":4.6502285102557575e+27,"mass_msun":0.00233867,"constellation":"Cygnus","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/kepler-17-b","radius_km":93630.508,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-17","host_v_mag":14.314,"uncertainties":{"mass_kg":[2.087869886579866e+26,2.087869886579866e+26],"radius_km":[1403.182,1403.182],"distance_ly":[33.73435414724277,33.73435414724277],"inclination_deg":[0.15,0.15],"host_temperature_k":[85,85],"semi_major_axis_km":[53855.233452,55351.212158999995],"orbital_period_days":[2e-7,2e-7]},"host_mass_solar":1.04,"inclination_deg":87.2,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.01034,"planets_in_system":1,"discovery_facility":"Kepler","host_spectral_type":"G2 V","host_temperature_k":5781,"orbital_period_days":1.4857108,"transit_midpoint_bjd":2455185.678035,"eccentricity_upper_limit":0.011,"equilibrium_temperature_k":1570},"designations":[{"catalog":"Exoplanet","designation":"Kepler-17 b"},{"catalog":"Host star","designation":"Kepler-17"}],"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."}