{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.685","julian_year":2026.685,"time":"2026-09-08T04:02:00.935Z","years_from_j2000":26.685,"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-186-f","name":"Kepler-186 f","class":"terrestrial_planet","category":"exoplanet","object_type":"Terrestrial planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":579.2341574422733,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":298.652736,"dec_deg":43.9549884,"epoch_ra_deg":298.869353,"epoch_dec_deg":44.024941,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-186","semi_major_axis_km":64626280.1424,"periapsis_km":null,"mass_kg":1.0212407053923257e+25,"mass_msun":0.00000513597,"constellation":"Cygnus","discovered":"2014","featured":true,"url":"https://spacecatalog.org/object/kepler-186-f","radius_km":7462.377,"radius_kind":null,"data_quality":null,"description":"The first Earth-sized planet found in the habitable zone of another star, circling a red dwarf every 130 days.","properties":{"host_star":"Kepler-186","host_v_mag":15.138,"uncertainties":{"radius_km":[510.24800000000005,510.24800000000005],"distance_ly":[2.524450363527594,2.524450363527594],"host_mass_solar":[0.021,0.024],"inclination_deg":[0.1,0.04],"host_radius_solar":[0.021,0.023],"host_temperature_k":[90,90],"semi_major_axis_km":[7928687.147099999,25581235.8897],"orbital_period_days":[0.0012,0.0013]},"host_mass_solar":0.544,"inclination_deg":89.96,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.523,"planets_in_system":5,"discovery_facility":"Kepler","host_spectral_type":"M1","host_temperature_k":3755,"orbital_period_days":129.9441,"transit_midpoint_bjd":2455789.494,"eccentricity_lower_limit":0.04,"equilibrium_temperature_k":177},"designations":[{"catalog":"Exoplanet","designation":"Kepler-186 f"}],"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."}