{"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":"2026-09-01T23:05:09.479Z","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-1647","name":"Kepler-1647","class":"star","category":"star","object_type":null,"mag":13.668,"mag_band":"V","abs_mag":null,"abs_mag_band":null,"distance_ly":3954.4830016266556,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":298.150057,"dec_deg":40.6561751,"epoch_ra_deg":298.379916,"epoch_dec_deg":40.72492,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":null,"semi_major_axis_km":null,"periapsis_km":null,"mass_kg":null,"mass_msun":null,"constellation":"Cygnus","discovered":null,"featured":false,"url":"https://spacecatalog.org/object/kepler-1647","radius_km":null,"radius_kind":null,"data_quality":null,"description":null,"properties":{"wds_id":"19526+4039","companions":[{"measured":2015,"magnitude":15.8,"components":"AB","discoverer_code":"KOI2939","separation_arcsec":2.8,"position_angle_deg":176},{"measured":2013,"magnitude":21.2,"components":"AC","discoverer_code":"KOI2939","separation_arcsec":4.3,"position_angle_deg":203},{"measured":2013,"magnitude":20.8,"components":"AD","discoverer_code":"KOI2939","separation_arcsec":4.8,"position_angle_deg":301},{"measured":2013,"magnitude":19.2,"components":"AF","discoverer_code":"KOI2939","separation_arcsec":8.2,"position_angle_deg":84},{"measured":2015,"magnitude":18.8,"components":"AE","discoverer_code":"KOI2939","separation_arcsec":12.3,"position_angle_deg":355}],"mass_solar":1.2207,"radius_solar":1.7903,"stars_in_system":2,"planets_in_system":1,"surface_temperature_k":6210,"stellar_parameters_method":"NASA Exoplanet Archive composite parameters"},"designations":[],"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."}