{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T11:11:56.645Z","years_from_j2000":26.68,"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-168443-c","name":"HD 168443 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":129.237833888371,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":275.0159879,"dec_deg":-9.5966905,"epoch_ra_deg":275.385395,"epoch_dec_deg":-9.585417,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 168443","semi_major_axis_km":425157148.5294,"periapsis_km":null,"mass_kg":3.2848944323377866e+28,"mass_msun":0.0165202,"constellation":"Serpens","discovered":"2000","featured":false,"url":"https://spacecatalog.org/object/hd-168443-c","radius_km":77812.82,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 168443","host_v_mag":6.92122,"eccentricity":0.21,"uncertainties":{"mass_kg":[1.7197008873676446e+27,4.840217729379638e+27],"distance_ly":[0.39693231168127674,0.39921540632529395],"eccentricity":[0.003,0.002],"host_mass_solar":[0.119,0.119],"inclination_deg":[16.088,22.283],"host_radius_solar":[0.04048,0.04048],"host_temperature_k":[44,44],"semi_major_axis_km":[17951744.483999997,16455765.776999999],"orbital_period_days":[0.72042,0.77149],"argument_of_periastron_deg":[0.85,0.685]},"host_mass_solar":0.98,"inclination_deg":91.218,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.711479,"planets_in_system":2,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"G5","host_temperature_k":5491,"orbital_period_days":1753.1096,"periastron_epoch_bjd":2450262.365,"transit_midpoint_bjd":2455599.41,"equilibrium_temperature_k":205.47,"argument_of_periastron_deg":65.597},"designations":[{"catalog":"Exoplanet","designation":"HD 168443 c"},{"catalog":"Host star","designation":"HD 168443"}],"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."}