{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.666","julian_year":2026.666,"time":"2026-09-01T10:14:15.179Z","years_from_j2000":26.666,"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-1663-b","name":"Kepler-1663 b","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1102.1672009630822,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":290.4015156,"dec_deg":48.8227234,"epoch_ra_deg":290.584377,"epoch_dec_deg":48.872879,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-1663","semi_major_axis_km":16036891.739039999,"periapsis_km":null,"mass_kg":6.509662975892603e+25,"mass_msun":0.000032738,"constellation":"Cygnus","discovered":"2020","featured":false,"url":"https://spacecatalog.org/object/kepler-1663-b","radius_km":21072.980642776,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-1663","host_v_mag":16.069,"eccentricity":0,"uncertainties":{"distance_ly":[11.112147788809448,11.112147788809448],"host_mass_solar":[0.020743,0.020743],"host_radius_solar":[0.019505,0.019505],"host_temperature_k":[157,157]},"host_mass_solar":0.610816,"inclination_deg":88.52,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.62859,"planets_in_system":1,"discovery_facility":"Kepler","host_temperature_k":3844,"orbital_period_days":17.6046,"transit_midpoint_bjd":2455003.49926,"equilibrium_temperature_k":362},"designations":[{"catalog":"Exoplanet","designation":"Kepler-1663 b"},{"catalog":"Host star","designation":"Kepler-1663"}],"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":"2026-08-30T09:56:50.739Z","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."}