{"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":"2026-08-27T19:36:43.874Z","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":"k2-211-b","name":"K2-211 b","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":888.1140318313609,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":21.1061587,"dec_deg":1.7049101,"epoch_ra_deg":21.451717,"epoch_dec_deg":1.845005,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-211","semi_major_axis_km":2122793.785233,"periapsis_km":null,"mass_kg":1.3915151131953915e+25,"mass_msun":0.00000699813,"constellation":"Cetus","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/k2-211-b","radius_km":8493.249594671,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-211","host_v_mag":13.1547,"eccentricity":0.19,"uncertainties":{"radius_km":[457.5488211880001,557.637601905],"distance_ly":[13.232164243968281,13.630075024782709],"eccentricity":[0.14,0.3],"host_mass_solar":[0.035,0.039],"inclination_deg":[3,3.8],"host_radius_solar":[0.027,0.029],"host_temperature_k":[86,85],"semi_major_axis_km":[29919.57414,31415.552847],"orbital_period_days":[0.000032,0.000031],"argument_of_periastron_deg":[110,130]},"host_mass_solar":0.851,"inclination_deg":84.1,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.818,"planets_in_system":1,"discovery_facility":"K2","host_temperature_k":5117,"orbital_period_days":0.669561,"transit_midpoint_bjd":2457432.6479,"equilibrium_temperature_k":1873,"argument_of_periastron_deg":-150},"designations":[{"catalog":"Exoplanet","designation":"K2-211 b"},{"catalog":"Host star","designation":"K2-211"}],"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."}