{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.665","julian_year":2026.665,"time":"2026-08-31T21:29:42.482Z","years_from_j2000":26.665,"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":"kepler-366-c","name":"Kepler-366 c","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":6054.375608280365,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":296.8520316,"dec_deg":49.0844359,"epoch_ra_deg":297.04089,"epoch_dec_deg":49.150095,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-366","semi_major_axis_km":16455765.776999999,"periapsis_km":null,"mass_kg":2.305256796967472e+25,"mass_msun":0.0000115935,"constellation":"Cygnus","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/kepler-366-c","radius_km":11416.799,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-366","host_v_mag":14.952,"eccentricity":0,"uncertainties":{"radius_km":[5166.261,5166.261],"distance_ly":[312.1968847504668,347.2913109927884],"host_mass_solar":[0.031,0.033],"host_radius_solar":[0.47,0.47],"host_temperature_k":[200,200],"orbital_period_days":[0.000095,0.000095]},"host_mass_solar":1.088,"inclination_deg":89.93,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.048,"planets_in_system":2,"discovery_facility":"Kepler","host_temperature_k":6209,"orbital_period_days":12.51616,"transit_midpoint_bjd":2454968.0286,"equilibrium_temperature_k":848},"designations":[{"catalog":"Exoplanet","designation":"Kepler-366 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":"2026-08-30T09:56:50.739Z","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."}