{"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":"2026-09-06T13:29:04.994Z","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":"mu2-sco-b","name":"μ² Sco b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":null,"distance_method":null,"ra_deg":253.0838724,"dec_deg":-38.0176339,"epoch_ra_deg":253.539656,"epoch_dec_deg":-38.062778,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"μ² Sco","semi_major_axis_km":36262523857.68,"periapsis_km":null,"mass_kg":2.733299423649678e+28,"mass_msun":0.0137462,"constellation":"Scorpius","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/mu2-sco-b","radius_km":78450.63,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"μ² Sco","host_v_mag":3.56,"eccentricity":0.56,"uncertainties":{"mass_kg":[1.5184996798053766e+27,1.5184996798053766e+27],"eccentricity":[0.26,0.27],"host_mass_solar":[0.3,0.3],"inclination_deg":[20.5,21.5],"host_radius_solar":[0.2,0.2],"host_temperature_k":[900,900],"semi_major_axis_km":[7794049063.469999,17128956195.149998]},"host_mass_solar":9.1,"inclination_deg":96.6,"stars_in_system":1,"discovery_method":"Imaging","host_radius_solar":5.6,"planets_in_system":1,"discovery_facility":"Paranal Observatory","host_spectral_type":"B2 IV","host_temperature_k":21700,"equilibrium_temperature_k":159.05},"designations":[{"catalog":"Exoplanet","designation":"mu2 Sco b"},{"catalog":"Host star","designation":"mu2 Sco"}],"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."}