{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.670","julian_year":2026.67,"time":"2026-09-02T14:58:03.946Z","years_from_j2000":26.67,"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":"k2-84-c","name":"K2-84 c","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":929.1412425843499,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":55.8093566,"dec_deg":16.6344396,"epoch_ra_deg":56.19011,"epoch_dec_deg":16.719936,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"K2-84","semi_major_axis_km":26448903.53976,"periapsis_km":null,"mass_kg":2.8546962408042795e+25,"mass_msun":0.0000143567,"constellation":"Taurus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/k2-84-c","radius_km":12947.543,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"K2-84","host_v_mag":13.386,"uncertainties":{"radius_km":[2040.9920000000002,2040.9920000000002],"distance_ly":[7.270025659306211,7.38418039150707],"host_mass_solar":[0.07,0.07],"host_radius_solar":[0.12,0.12],"host_temperature_k":[154,154],"semi_major_axis_km":[643270.84401,643270.84401],"orbital_period_days":[0.0052,0.0052]},"host_mass_solar":0.95,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.93,"planets_in_system":2,"discovery_facility":"K2","host_temperature_k":5652,"orbital_period_days":27.86,"transit_midpoint_bjd":2457068.615,"equilibrium_temperature_k":625.08},"designations":[{"catalog":"Exoplanet","designation":"K2-84 c"}],"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":"2026-09-01T22:58:55.274Z","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."}