{"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":"2026-09-07T23:27:35.842Z","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-218566-b","name":"HD 218566 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":94.0224036299165,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":347.297417,"dec_deg":-2.2611645,"epoch_ra_deg":347.643019,"epoch_dec_deg":-2.11564,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 218566","semi_major_axis_km":103222530.78299998,"periapsis_km":null,"mass_kg":3.7962682268402685e+26,"mass_msun":0.00019092,"constellation":"Pisces","discovered":"2010","featured":false,"url":"https://spacecatalog.org/object/hd-218566-b","radius_km":59443.89200000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 218566","host_v_mag":8.6,"eccentricity":0.3,"uncertainties":{"mass_kg":[1.1388804680520805e+26,1.1388804680520805e+26],"distance_ly":[0.13926877328504944,0.13992108604048292],"eccentricity":[0.1,0.1],"host_mass_solar":[0.32,0.32],"host_radius_solar":[0.04,0.04],"host_temperature_k":[100,100],"semi_major_axis_km":[1495978.707,1495978.707],"orbital_period_days":[0.4,0.4],"argument_of_periastron_deg":[21,23]},"host_mass_solar":0.76,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.85,"planets_in_system":1,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"K3V","host_temperature_k":4730,"orbital_period_days":225.7,"periastron_epoch_bjd":2450360,"transit_midpoint_bjd":2454667.4,"equilibrium_temperature_k":253.15,"argument_of_periastron_deg":44},"designations":[{"catalog":"Exoplanet","designation":"HD 218566 b"},{"catalog":"Host star","designation":"HD 218566"}],"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."}