{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T10:30:00.882Z","years_from_j2000":26.683,"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":"gj-504-b","name":"GJ 504 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":57.17488685736741,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":199.192348,"dec_deg":9.4249781,"epoch_ra_deg":199.52879,"epoch_dec_deg":9.283096,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"GJ 504","semi_major_axis_km":6507507375.45,"periapsis_km":null,"mass_kg":7.59241701032318e+27,"mass_msun":0.00381834,"constellation":"Virgo","discovered":"2013","featured":false,"url":"https://spacecatalog.org/object/gj-504-b","radius_km":77211.35981239601,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"GJ 504","host_v_mag":5.18799,"uncertainties":{"mass_kg":[1.8979549483841003e+27,8.541394484515231e+27],"radius_km":[2144.759987702,2859.6800048630002],"distance_ly":[0.25374966186362635,0.25603275650764357],"host_mass_solar":[0.08,0.08],"host_radius_solar":[0.04,0.03],"host_temperature_k":[25,25]},"host_mass_solar":1.22,"stars_in_system":1,"discovery_method":"Imaging","host_radius_solar":1.26,"planets_in_system":1,"discovery_facility":"Subaru Telescope","host_spectral_type":"G0 V","host_temperature_k":6234,"equilibrium_temperature_k":510},"designations":[{"catalog":"Exoplanet","designation":"GJ 504 b"},{"catalog":"Host star","designation":"GJ 504"}],"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."}