{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T13:54:31.599Z","years_from_j2000":26.681,"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":"omi-uma-b","name":"ο 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":179.10844866677195,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":127.5649503,"dec_deg":60.7177048,"epoch_ra_deg":128.121893,"epoch_dec_deg":60.627759,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"ο UMa","semi_major_axis_km":552165740.7536999,"periapsis_km":null,"mass_kg":6.930052913729705e+27,"mass_msun":0.00348522,"constellation":"Ursa Major","discovered":"2012","featured":false,"url":"https://spacecatalog.org/object/omi-uma-b","radius_km":82915.3,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"ο UMa","host_v_mag":3.35214,"eccentricity":0.149,"uncertainties":{"mass_kg":[5.656411307513914e+26,3.340699295452385e+26],"distance_ly":[6.721300169435562,6.721300169435562],"eccentricity":[0.079,0.044],"host_mass_solar":[0.16,0.14],"host_radius_solar":[1.04,1.19],"semi_major_axis_km":[3141555.2846999997,2991957.414],"orbital_period_days":[13.59,12.76],"argument_of_periastron_deg":[21.4,30.9]},"host_mass_solar":2.72,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":13.84,"planets_in_system":1,"discovery_facility":"Okayama Astrophysical Observatory","host_spectral_type":"G4 II-III","host_temperature_k":5075,"orbital_period_days":1569.81,"periastron_epoch_bjd":2453348.8,"equilibrium_temperature_k":473.88,"argument_of_periastron_deg":40.8},"designations":[{"catalog":"Exoplanet","designation":"omi UMa b"},{"catalog":"Host star","designation":"omi UMa"}],"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."}