{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-01T22:46:48.169Z","years_from_j2000":26.668,"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":"k2-3-b","name":"K2-3 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":143.74592188196718,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":172.3353708,"dec_deg":-1.4551364,"epoch_ra_deg":172.678784,"epoch_dec_deg":-1.603025,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-3","semi_major_axis_km":11174960.941289999,"periapsis_km":null,"mass_kg":3.051777780441395e+25,"mass_msun":0.0000153478,"constellation":"Leo","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/k2-3-b","radius_km":13253.6918,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-3","host_v_mag":12.168,"eccentricity":0.107,"uncertainties":{"mass_kg":[3.8221874353864827e+24,3.8819091140643965e+24],"radius_km":[427.33270000000005,484.73560000000003],"distance_ly":[0.352738122500658,0.352738122500658],"eccentricity":[0.059,0.057],"host_mass_solar":[0.027,0.029],"inclination_deg":[0.22,0.34],"host_radius_solar":[0.016,0.018],"host_temperature_k":[63,61],"semi_major_axis_km":[179517.44483999998,194477.23190999997],"orbital_period_days":[0.0000091,0.0000088],"argument_of_periastron_deg":[34,32]},"host_mass_solar":0.549,"inclination_deg":89.4,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.546,"planets_in_system":3,"discovery_facility":"K2","host_spectral_type":"M V","host_temperature_k":3844,"orbital_period_days":10.0546535,"transit_midpoint_bjd":2457165.32947,"equilibrium_temperature_k":501.3,"argument_of_periastron_deg":188},"designations":[{"catalog":"Exoplanet","designation":"K2-3 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":"2026-08-30T09:56:50.739Z","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."}