{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.654","julian_year":2026.654,"time":"2026-08-27T22:30:17.815Z","years_from_j2000":26.654,"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":"k2-129-b","name":"K2-129 b","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":90.65744828101285,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":289.1485491,"dec_deg":-25.6463233,"epoch_ra_deg":289.560487,"epoch_dec_deg":-25.598979,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-129","semi_major_axis_km":8527078.6299,"periapsis_km":null,"mass_kg":6.688828011926346e+24,"mass_msun":0.00000336391,"constellation":"Sagittarius","discovered":"2017","featured":false,"url":"https://spacecatalog.org/object/k2-129-b","radius_km":6633.224,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-129","host_v_mag":13.639,"eccentricity":0.13,"uncertainties":{"radius_km":[574.029,637.8100000000001],"distance_ly":[0.24200803226582362,0.2433126577766906],"eccentricity":[0.109504,0.210105],"host_mass_solar":[0.074196,0.067677],"inclination_deg":[0.48,0.5],"host_radius_solar":[0.029677,0.030968],"host_temperature_k":[83.62,89.05],"semi_major_axis_km":[598391.4828,448793.61209999997],"orbital_period_days":[0.000291,0.000292],"argument_of_periastron_deg":[143.1102,97.2451]},"host_mass_solar":0.360031,"inclination_deg":89.21,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.36001,"planets_in_system":1,"discovery_facility":"K2","host_temperature_k":3459.09,"orbital_period_days":8.239493,"transit_midpoint_bjd":2457335.009,"equilibrium_temperature_k":419.19,"argument_of_periastron_deg":39.89},"designations":[{"catalog":"Exoplanet","designation":"K2-129 b"},{"catalog":"Host star","designation":"K2-129"}],"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":"2026-08-27T19:16:43.430Z","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."}