{"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":"2026-09-06T10:47:28.815Z","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-16417-b","name":"HD 16417 b","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":82.82284593187896,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":39.2441029,"dec_deg":-34.5790905,"epoch_ra_deg":39.524254,"epoch_dec_deg":-34.462042,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 16417","semi_major_axis_km":20943701.898000002,"periapsis_km":null,"mass_kg":1.319849098781895e+26,"mass_msun":0.0000663771,"constellation":"Fornax","discovered":"2008","featured":false,"url":"https://spacecatalog.org/object/hd-16417-b","radius_km":31890.5,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 16417","host_v_mag":5.78,"eccentricity":0.2,"uncertainties":{"mass_kg":[1.1944335735582758e+25,1.1944335735582758e+25],"distance_ly":[0.1148070449562937,0.11513320133401042],"eccentricity":[0.09,0.09],"host_radius_solar":[0.019743,0.035721],"host_temperature_k":[17,17],"semi_major_axis_km":[1495978.707,1495978.707],"orbital_period_days":[0.01,0.01],"argument_of_periastron_deg":[26,26]},"host_mass_solar":1.2,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":1.639984,"planets_in_system":1,"discovery_facility":"Anglo-Australian Telescope","host_spectral_type":"G1 V","host_temperature_k":5841,"orbital_period_days":17.24,"periastron_epoch_bjd":2450099.74,"equilibrium_temperature_k":964,"argument_of_periastron_deg":77},"designations":[{"catalog":"Exoplanet","designation":"HD 16417 b"},{"catalog":"Host star","designation":"HD 16417"}],"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."}