{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T09:21:26.342Z","years_from_j2000":26.677,"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-1148-b","name":"GJ 1148 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":35.92384191085527,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":175.4326081,"dec_deg":42.7515862,"epoch_ra_deg":175.789409,"epoch_dec_deg":42.602668,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"GJ 1148","semi_major_axis_km":24833246.536199998,"periapsis_km":null,"mass_kg":5.775086328154264e+26,"mass_msun":0.000290437,"constellation":"Ursa Major","discovered":"2010","featured":false,"url":"https://spacecatalog.org/object/gj-1148-b","radius_km":75899.39,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"GJ 1148","host_v_mag":11.939,"eccentricity":0.38,"uncertainties":{"mass_kg":[6.091611225147207e+24,8.420756693585845e+24],"distance_ly":[0.02120016455158832,0.02087400817387158],"eccentricity":[0.012,0.01],"host_mass_solar":[0.020144,0.020144],"host_radius_solar":[0.010569,0.010569],"host_temperature_k":[157,157],"semi_major_axis_km":[149597.8707,149597.8707],"orbital_period_days":[0.001,0.002],"argument_of_periastron_deg":[1.8,2]},"host_mass_solar":0.344045,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.358519,"planets_in_system":2,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"M5","host_temperature_k":3287,"orbital_period_days":41.38,"transit_midpoint_bjd":2454796.92,"equilibrium_temperature_k":232.94,"argument_of_periastron_deg":258.1},"designations":[{"catalog":"Exoplanet","designation":"GJ 1148 b"},{"catalog":"Host star","designation":"GJ 1148"}],"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."}