{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T09:33:40.452Z","years_from_j2000":26.683,"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":"k2-222-b","name":"K2-222 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":330.4649034663816,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":16.4625203,"dec_deg":11.7537171,"epoch_ra_deg":16.815277,"epoch_dec_deg":11.89769,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-222","semi_major_axis_km":17742307.465019997,"periapsis_km":null,"mass_kg":4.479125900843535e+25,"mass_msun":0.0000225262,"constellation":"Pisces","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/k2-222-b","radius_km":14510.1775,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-222","host_v_mag":9.543,"eccentricity":0.021,"uncertainties":{"mass_kg":[8.958251801687069e+24,8.958251801687069e+24],"radius_km":[637.8100000000001,637.8100000000001],"distance_ly":[2.0384773607296465,2.0613083071698184],"eccentricity":[0.017,0.051],"host_mass_solar":[0.05,0.05],"inclination_deg":[0.32,0.36],"host_radius_solar":[0.043,0.043],"host_temperature_k":[119,119],"semi_major_axis_km":[314155.52846999996,314155.52846999996],"orbital_period_days":[0.000011,0.0000099]},"host_mass_solar":0.94,"inclination_deg":88.91,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.072,"planets_in_system":1,"discovery_facility":"K2","host_spectral_type":"G0","host_temperature_k":5942,"orbital_period_days":15.3889274,"transit_midpoint_bjd":2459491.9547,"equilibrium_temperature_k":803},"designations":[{"catalog":"Exoplanet","designation":"K2-222 b"},{"catalog":"Host star","designation":"K2-222"}],"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."}