{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.663","julian_year":2026.663,"time":"2026-08-31T03:54:50.554Z","years_from_j2000":26.663,"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":"k2-266-e","name":"K2-266 e","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":252.96232036781817,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":157.9356855,"dec_deg":0.9372782,"epoch_ra_deg":158.280527,"epoch_dec_deg":0.799469,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-266","semi_major_axis_km":18684774.05043,"periapsis_km":null,"mass_kg":8.540200050941673e+25,"mass_msun":0.0000429499,"constellation":"Sextans","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/k2-266-e","radius_km":17412.213,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-266","host_v_mag":11.625,"eccentricity":0.043,"uncertainties":{"mass_kg":[2.9860839338956896e+25,3.8221874353864827e+25],"radius_km":[701.591,892.9340000000001],"distance_ly":[1.1575289845167223,1.1679659886036582],"eccentricity":[0.03,0.036],"host_mass_solar":[0.033,0.033],"inclination_deg":[0.18,0.25],"host_radius_solar":[0.022,0.024],"host_temperature_k":[57,49],"semi_major_axis_km":[299195.7414,284235.95433],"orbital_period_days":[0.0012,0.0012],"argument_of_periastron_deg":[58,57]},"host_mass_solar":0.686,"inclination_deg":89.45,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":0.703,"planets_in_system":4,"discovery_facility":"K2","host_temperature_k":4285,"orbital_period_days":19.482,"periastron_epoch_bjd":2457938.6,"transit_midpoint_bjd":2457938.541,"equilibrium_temperature_k":490.1,"argument_of_periastron_deg":89},"designations":[{"catalog":"Exoplanet","designation":"K2-266 e"},{"catalog":"Host star","designation":"K2-266"}],"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."}