{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.668","julian_year":2026.668,"time":"2026-09-01T22:30:33.345Z","years_from_j2000":26.668,"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-646-b","name":"Kepler-646 b","class":"super_earth","category":"exoplanet","object_type":"Super-Earth","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1473.5549451415836,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":290.4714596,"dec_deg":44.3870422,"epoch_ra_deg":290.677567,"epoch_dec_deg":44.437405,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"Kepler-646","semi_major_axis_km":16831256.432457,"periapsis_km":null,"mass_kg":2.7591415549196174e+25,"mass_msun":0.0000138761,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/kepler-646-b","radius_km":12692.419,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"Kepler-646","host_v_mag":14.026,"eccentricity":0,"uncertainties":{"radius_km":[1211.8390000000002,2359.897],"distance_ly":[10.376665157058193,10.376665157058193],"host_mass_solar":[0.061,0.057],"host_radius_solar":[0.078,0.133],"host_temperature_k":[139.42,117.96],"semi_major_axis_km":[73302.956643,73302.956643],"orbital_period_days":[0.000043,0.000043]},"host_mass_solar":0.93,"inclination_deg":89.3,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.91,"planets_in_system":1,"discovery_facility":"Kepler","host_temperature_k":5634,"orbital_period_days":15.87364565,"transit_midpoint_bjd":2455015.40134,"equilibrium_temperature_k":632},"designations":[{"catalog":"Exoplanet","designation":"Kepler-646 b"},{"catalog":"Host star","designation":"Kepler-646"}],"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."}