{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T14:31:20.593Z","years_from_j2000":26.681,"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":"koi-1831-d","name":"KOI-1831 d","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1635.9155899689786,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":286.4714473,"dec_deg":49.6490933,"epoch_ra_deg":286.646031,"epoch_dec_deg":49.68952,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-324","semi_major_axis_km":29805879.758268,"periapsis_km":null,"mass_kg":1.3317934345174775e+25,"mass_msun":0.00000669778,"constellation":"Draco","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/koi-1831-d","radius_km":7207.253,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-324","host_v_mag":14.222,"eccentricity":0,"uncertainties":{"mass_kg":[5.016621008944759e+24,2.9860839338956896e+24],"radius_km":[318.90500000000003,318.90500000000003],"distance_ly":[11.836214947340618,12.005816263753326],"host_mass_solar":[0.027,0.017],"host_radius_solar":[0.022,0.023],"host_temperature_k":[60,60],"semi_major_axis_km":[243844.52924099998,243844.52924099998]},"host_mass_solar":0.901,"inclination_deg":89.62,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.835,"planets_in_system":4,"discovery_facility":"Kepler","host_temperature_k":5233,"orbital_period_days":34.169,"transit_midpoint_bjd":2454981.80509,"equilibrium_temperature_k":475},"designations":[{"catalog":"Exoplanet","designation":"KOI-1831 d"},{"catalog":"Host star","designation":"Kepler-324"}],"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."}