{"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":"2026-09-06T17:18:01.016Z","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":"hd-164604-b","name":"HD 164604 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":128.38591342977486,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":270.7787177,"dec_deg":-28.5608343,"epoch_ra_deg":271.204356,"epoch_dec_deg":-28.56054,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 164604","semi_major_axis_km":203752299.8934,"periapsis_km":null,"mass_kg":2.505524471678871e+28,"mass_msun":0.0126006,"constellation":"Sagittarius","discovered":"2009","featured":false,"url":"https://spacecatalog.org/object/hd-164604-b","radius_km":78450.63,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 164604","host_v_mag":9.62,"eccentricity":0.479,"uncertainties":{"mass_kg":[2.847186899635081e+27,3.4166242795620973e+27],"distance_ly":[0.3127839662303569,0.3140885917412239],"eccentricity":[0.021,0.027],"host_mass_solar":[0.02,0.02],"inclination_deg":[1.3,1.4],"host_radius_solar":[0.02,0.02],"host_temperature_k":[31,31],"semi_major_axis_km":[1795174.4483999999,1795174.4483999999],"orbital_period_days":[1.7,1.5],"argument_of_periastron_deg":[2,1.7]},"host_mass_solar":0.77,"inclination_deg":10.6,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.78,"planets_in_system":2,"discovery_facility":"Las Campanas Observatory","host_spectral_type":"K3.5 V","host_temperature_k":4663,"orbital_period_days":653.9,"periastron_epoch_bjd":2453831.3,"equilibrium_temperature_k":170.16,"argument_of_periastron_deg":64.6},"designations":[{"catalog":"Exoplanet","designation":"HD 164604 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."}