{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.685","julian_year":2026.685,"time":"2026-09-08T01:01:31.763Z","years_from_j2000":26.685,"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":"17-sco-b","name":"17 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":407.5421786484024,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":243.4620874,"dec_deg":-11.8377905,"epoch_ra_deg":243.834329,"epoch_dec_deg":-11.906258,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"17 Sco","semi_major_axis_km":216916912.515,"periapsis_km":null,"mass_kg":8.199898270949033e+27,"mass_msun":0.00412385,"constellation":"Scorpius","discovered":"2020","featured":false,"url":"https://spacecatalog.org/object/17-sco-b","radius_km":82277.49,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"17 Sco","host_v_mag":5.22606,"eccentricity":0.06,"uncertainties":{"mass_kg":[2.2777495197080647e+26,2.8471868996350808e+26],"distance_ly":[8.447450182863655,8.447450182863655],"eccentricity":[0.02,0.03],"host_mass_solar":[0.14,0.13],"host_radius_solar":[0.74,0.78],"host_temperature_k":[10,11],"semi_major_axis_km":[2991957.414,2991957.414],"orbital_period_days":[2.09,2.01],"argument_of_periastron_deg":[106.77,113.18]},"host_mass_solar":1.22,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":25.92,"planets_in_system":1,"discovery_facility":"Lick Observatory","host_spectral_type":"K3 III","host_temperature_k":4157,"orbital_period_days":578.38,"periastron_epoch_bjd":2453294.41,"equilibrium_temperature_k":847.51,"argument_of_periastron_deg":57.03},"designations":[{"catalog":"Exoplanet","designation":"17 Sco b"},{"catalog":"Host star","designation":"17 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."}