{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T13:14:34.680Z","years_from_j2000":26.678,"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-133131-a-b","name":"HD 133131 A b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":167.88442924040564,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":225.8984524,"dec_deg":-27.8431369,"epoch_ra_deg":226.298806,"epoch_dec_deg":-27.948477,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 133131 A","semi_major_axis_km":215420933.80799997,"periapsis_km":null,"mass_kg":2.6953504410565906e+27,"mass_msun":0.00135553,"constellation":"Libra","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hd-133131-a-b","radius_km":86742.16,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 133131 A","host_v_mag":7.66,"eccentricity":0.33,"uncertainties":{"mass_kg":[7.592536453680536e+25,7.592536453680536e+25],"distance_ly":[0.4836899081539304,0.48629915917566446],"eccentricity":[0.03,0.03],"host_radius_solar":[0.052146,0.037412],"host_temperature_k":[19,19],"semi_major_axis_km":[747989.3535,747989.3535],"orbital_period_days":[3,3],"argument_of_periastron_deg":[4.7,4.7]},"host_mass_solar":0.95,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":0.955014,"planets_in_system":3,"discovery_facility":"Las Campanas Observatory","host_spectral_type":"G2 V","host_temperature_k":5799,"orbital_period_days":649,"periastron_epoch_bjd":2452327,"equilibrium_temperature_k":227.72,"argument_of_periastron_deg":16},"designations":[{"catalog":"Exoplanet","designation":"HD 133131 A b"},{"catalog":"Host star","designation":"HD 133131 A"}],"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."}