{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T12:56:09.481Z","years_from_j2000":26.68,"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":"hd-224538-b","name":"HD 224538 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":257.86184147387905,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":359.7164302,"dec_deg":-61.5868613,"epoch_ra_deg":0.065388,"epoch_dec_deg":-61.437307,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 224538","semi_major_axis_km":355294942.91249996,"periapsis_km":null,"mass_kg":1.239665176102906e+28,"mass_msun":0.00623445,"constellation":"Tucana","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hd-224538-b","radius_km":81001.87,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 224538","host_v_mag":8.06,"eccentricity":0.476,"uncertainties":{"mass_kg":[6.62445485297179e+26,3.4849567651413947e+27],"distance_ly":[0.6020846732651083,0.6046939242868423],"eccentricity":[0.013,0.014],"host_mass_solar":[0.181,0.181],"inclination_deg":[25.504,25.897],"host_radius_solar":[0.06,0.06],"host_temperature_k":[100,100],"semi_major_axis_km":[18400538.0961,16605363.647699999],"orbital_period_days":[3.68089,3.88199],"argument_of_periastron_deg":[1.355,1.244]},"host_mass_solar":1.23,"inclination_deg":91.125,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.54,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"F8/G0 IV/V","host_temperature_k":6097,"orbital_period_days":1202.05199,"periastron_epoch_bjd":2452421.823,"equilibrium_temperature_k":236.74,"argument_of_periastron_deg":26.829},"designations":[{"catalog":"Exoplanet","designation":"HD 224538 b"},{"catalog":"Host star","designation":"HD 224538"}],"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."}