{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T19:17:00.746Z","years_from_j2000":26.684,"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-128717-b","name":"HD 128717 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":240.16851029550116,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":219.0881687,"dec_deg":57.5609512,"epoch_ra_deg":219.286867,"epoch_dec_deg":57.443554,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 128717","semi_major_axis_km":725549672.8949999,"periapsis_km":null,"mass_kg":3.758286707518307e+28,"mass_msun":0.018901,"constellation":"Draco","discovered":"2025","featured":false,"url":"https://spacecatalog.org/object/hd-128717-b","radius_km":77175.01000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 128717","host_v_mag":8.32,"eccentricity":0.85,"uncertainties":{"mass_kg":[9.490622998783604e+26,9.490622998783604e+26],"distance_ly":[0.547942714564129,0.5508781219635797],"eccentricity":[0.002,0.002],"host_mass_solar":[0.068,0.058],"inclination_deg":[1.9,1.6],"host_radius_solar":[0.024,0.024],"host_temperature_k":[40,40],"semi_major_axis_km":[1495978.707,2991957.414],"orbital_period_days":[20,20],"argument_of_periastron_deg":[0.3,0.4]},"host_mass_solar":1.212,"inclination_deg":130.3,"stars_in_system":1,"discovery_method":"Astrometry","host_radius_solar":1.248,"planets_in_system":1,"discovery_facility":"European Space Agency (ESA) Gaia Satellite","host_temperature_k":6210,"orbital_period_days":3420,"periastron_epoch_bjd":2460189.634,"equilibrium_temperature_k":151.9,"argument_of_periastron_deg":-105.7},"designations":[{"catalog":"Exoplanet","designation":"HD 128717 b"},{"catalog":"Host star","designation":"HD 128717"}],"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."}