{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T09:28:43.816Z","years_from_j2000":26.677,"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":"k2-16-b","name":"K2-16 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":1092.516233746444,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":175.0972238,"dec_deg":4.5574311,"epoch_ra_deg":175.442516,"epoch_dec_deg":4.408597,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-16","semi_major_axis_km":9978177.975689998,"periapsis_km":null,"mass_kg":2.830807569333114e+25,"mass_msun":0.0000142365,"constellation":"Virgo","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/k2-16-b","radius_km":12883.762,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-16","host_v_mag":14.668,"uncertainties":{"radius_km":[1530.7440000000001,1530.7440000000001],"distance_ly":[13.628444242894123,13.628444242894123],"host_mass_solar":[0.03,0.03],"inclination_deg":[1.86,1.47],"host_radius_solar":[0.03,0.03],"host_temperature_k":[60,60],"semi_major_axis_km":[164557.65777,164557.65777],"orbital_period_days":[0.00087,0.00087]},"host_mass_solar":0.68,"inclination_deg":87.97,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.66,"planets_in_system":3,"discovery_facility":"K2","host_spectral_type":"K3 V","host_temperature_k":4742,"orbital_period_days":7.6188,"transit_midpoint_bjd":2456811.6871,"equilibrium_temperature_k":658},"designations":[{"catalog":"Exoplanet","designation":"K2-16 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."}