{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.667","julian_year":2026.667,"time":"2026-09-01T10:42:18.397Z","years_from_j2000":26.667,"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":"k2-9-b","name":"K2-9 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":270.58944180151957,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":176.263724,"dec_deg":0.0054085,"epoch_ra_deg":176.607693,"epoch_dec_deg":-0.143619,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-9","semi_major_axis_km":13613406.233699998,"periapsis_km":null,"mass_kg":3.398163516773295e+25,"mass_msun":0.0000170899,"constellation":"Virgo","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/k2-9-b","radius_km":14350.725,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-9","host_v_mag":15.86,"uncertainties":{"radius_km":[6122.976000000001,3380.3930000000005],"distance_ly":[1.2113447868399851,1.2221079473046375],"host_mass_solar":[0.14,0.14],"inclination_deg":[0.08,1.593],"host_radius_solar":[0.11,0.11],"host_temperature_k":[150,150],"semi_major_axis_km":[2393565.9312,1944772.3190999997],"orbital_period_days":[0.0015,0.0015]},"host_mass_solar":0.3,"inclination_deg":87.983,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.31,"planets_in_system":1,"discovery_facility":"K2","host_spectral_type":"M2.5 V","host_temperature_k":3390,"orbital_period_days":18.4498,"transit_midpoint_bjd":2456822.6712,"equilibrium_temperature_k":314},"designations":[{"catalog":"Exoplanet","designation":"K2-9 b"},{"catalog":"Host star","designation":"K2-9"}],"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."}