{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.671","julian_year":2026.671,"time":"2026-09-03T02:21:44.684Z","years_from_j2000":26.671,"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-411-c","name":"Kepler-411 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":501.2240750199826,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":287.6057027,"dec_deg":49.5233937,"epoch_ra_deg":287.781908,"epoch_dec_deg":49.566635,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-411","semi_major_axis_km":11055282.644729998,"periapsis_km":null,"mass_kg":1.576652317096924e+26,"mass_msun":0.0000792921,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/kepler-411-c","radius_km":28197.580100000003,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-411","host_v_mag":12.448,"eccentricity":0.108,"uncertainties":{"mass_kg":[3.523579041996914e+25,3.523579041996914e+25],"radius_km":[395.4422,395.4422],"distance_ly":[1.4774883910568477,1.4840115186111826],"eccentricity":[0.004,0.003],"host_mass_solar":[0.039,0.039],"inclination_deg":[0.04,0.04],"host_radius_solar":[0.018,0.018],"host_temperature_k":[51,46],"semi_major_axis_km":[149597.8707,149597.8707],"orbital_period_days":[0.000002,0.000002],"argument_of_periastron_deg":[1.7,1.6]},"host_mass_solar":0.87,"inclination_deg":88.61,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":0.82,"planets_in_system":4,"discovery_facility":"Kepler","host_spectral_type":"K2 V","host_temperature_k":4974,"orbital_period_days":7.834435,"transit_midpoint_bjd":2454968.2224,"equilibrium_temperature_k":838,"argument_of_periastron_deg":103},"designations":[{"catalog":"Exoplanet","designation":"Kepler-411 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":"2026-09-02T19:50:56.720Z","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."}