{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T08:47:41.414Z","years_from_j2000":26.675,"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":"47-uma-b","name":"47 UMa b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":44.998816964445936,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":164.8647611,"dec_deg":40.4304931,"epoch_ra_deg":165.243501,"epoch_dec_deg":40.286633,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"47 UMa","semi_major_axis_km":314155528.46999997,"periapsis_km":null,"mass_kg":4.8021007391336926e+27,"mass_msun":0.00241505,"constellation":"Ursa Major","discovered":"1996","featured":false,"url":"https://spacecatalog.org/object/47-uma-b","radius_km":84190.92,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"47 UMa","host_v_mag":5.03352,"eccentricity":0.032,"uncertainties":{"mass_kg":[1.138892412387816e+26,1.3288073505835819e+26],"distance_ly":[0.09425919316013884,0.09425919316013884],"eccentricity":[0.014,0.014],"host_mass_solar":[0.137608,0.128402],"host_radius_solar":[0.058353,0.038883],"host_temperature_k":[113.53,92.94],"semi_major_axis_km":[2991957.414,2991957.414],"orbital_period_days":[2,2],"argument_of_periastron_deg":[23,23]},"host_mass_solar":1.06,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.21334,"planets_in_system":3,"discovery_facility":"Lick Observatory","host_spectral_type":"G0V","host_temperature_k":5872,"orbital_period_days":1078,"periastron_epoch_bjd":2451917,"transit_midpoint_bjd":2454415.6,"equilibrium_temperature_k":215.23,"argument_of_periastron_deg":334},"designations":[{"catalog":"Exoplanet","designation":"47 UMa b"}],"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."}