{"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":"2026-09-02T22:19:43.785Z","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-39-b","name":"Kepler-39 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":3448.810153614617,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":296.9603348,"dec_deg":46.0342954,"epoch_ra_deg":297.165107,"epoch_dec_deg":46.100255,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-39","semi_major_axis_km":24534050.7948,"periapsis_km":null,"mass_kg":3.8150805556238113e+28,"mass_msun":0.0191866,"constellation":"Cygnus","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/kepler-39-b","radius_km":88655.59000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-39","host_v_mag":14.355,"eccentricity":0.112,"uncertainties":{"mass_kg":[2.277784824775632e+27,2.467699762971398e+27],"radius_km":[7143.472000000001,6441.881],"distance_ly":[60.14323605096749,60.14323605096749],"eccentricity":[0.057,0.057],"host_mass_solar":[0.07,0.06],"inclination_deg":[0.22,0.22],"host_radius_solar":[0.1,0.1],"host_temperature_k":[100,100],"semi_major_axis_km":[448793.61209999997,448793.61209999997],"orbital_period_days":[0.000037,0.000037],"argument_of_periastron_deg":[14,22]},"host_mass_solar":1.29,"inclination_deg":89.07,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.4,"planets_in_system":1,"discovery_facility":"Kepler","host_spectral_type":"F7 V","host_temperature_k":6350,"orbital_period_days":21.08721,"transit_midpoint_bjd":2455942.60708,"equilibrium_temperature_k":897,"argument_of_periastron_deg":99},"designations":[{"catalog":"Exoplanet","designation":"Kepler-39 b"},{"catalog":"Host star","designation":"Kepler-39"}],"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."}