{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T11:32:54.525Z","years_from_j2000":26.675,"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":"k2-240-b","name":"K2-240 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":237.8022457751662,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":227.849371,"dec_deg":-17.8754464,"epoch_ra_deg":228.228938,"epoch_dec_deg":-17.977115,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-240","semi_major_axis_km":7674370.766909999,"periapsis_km":null,"mass_kg":2.783030226390783e+25,"mass_msun":0.0000139963,"constellation":"Libra","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/k2-240-b","radius_km":12756.2,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-240","host_v_mag":13.372,"uncertainties":{"radius_km":[637.8100000000001,1275.6200000000001],"distance_ly":[1.7043301517588425,1.7043301517588425],"host_mass_solar":[0.01,0.01],"inclination_deg":[0.64,0.51],"host_radius_solar":[0.01,0.01],"host_temperature_k":[17,17],"semi_major_axis_km":[134638.08362999998,134638.08362999998],"orbital_period_days":[0.001,0.001]},"host_mass_solar":0.58,"inclination_deg":89.26,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.54,"planets_in_system":2,"discovery_facility":"K2","host_spectral_type":"M0.5 V","host_temperature_k":3810,"orbital_period_days":6.034,"transit_midpoint_bjd":2457996.825,"equilibrium_temperature_k":586},"designations":[{"catalog":"Exoplanet","designation":"K2-240 b"}],"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."}