{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T18:06:29.677Z","years_from_j2000":26.687,"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-328-b","name":"GJ 328 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":66.94881502840505,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":133.7819507,"dec_deg":1.5420011,"epoch_ra_deg":134.129098,"epoch_dec_deg":1.439832,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"GJ 328","semi_major_axis_km":614847248.577,"periapsis_km":null,"mass_kg":4.764292745389369e+27,"mass_msun":0.00239603,"constellation":"Hydra","discovered":"2013","featured":false,"url":"https://spacecatalog.org/object/gj-328-b","radius_km":84828.73000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"GJ 328","host_v_mag":9.99,"eccentricity":0.227,"uncertainties":{"mass_kg":[4.365686579440458e+26,4.365686579440458e+26],"distance_ly":[0.05495734964527127,0.05495734964527127],"eccentricity":[0.015,0.015],"host_mass_solar":[0.08,0.08],"host_radius_solar":[0.07,0.07],"host_temperature_k":[71,71],"semi_major_axis_km":[26927616.725999996,23935659.312],"orbital_period_days":[17,17],"argument_of_periastron_deg":[6.3,6.3]},"host_mass_solar":0.65,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.63,"planets_in_system":2,"discovery_facility":"McDonald Observatory","host_spectral_type":"M0.0","host_temperature_k":3897,"orbital_period_days":3771,"periastron_epoch_bjd":2454500,"transit_midpoint_bjd":2456177,"equilibrium_temperature_k":73.57,"argument_of_periastron_deg":-76.2},"designations":[{"catalog":"Exoplanet","designation":"GJ 328 b"},{"catalog":"Host star","designation":"GJ 328"}],"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."}