{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T21:56:36.325Z","years_from_j2000":26.687,"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-216536-b","name":"HD 216536 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1227.1079245750352,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":343.2665641,"dec_deg":44.4777303,"epoch_ra_deg":343.566652,"epoch_dec_deg":44.620448,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 216536","semi_major_axis_km":91254701.12699999,"periapsis_km":null,"mass_kg":1.9930408190911408e+27,"mass_msun":0.00100233,"constellation":"Lacerta","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/hd-216536-b","radius_km":88017.78000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 216536","host_v_mag":9.229,"eccentricity":0.38,"uncertainties":{"mass_kg":[7.592536453680537e+26,7.592536453680537e+26],"distance_ly":[12.310772476918482,12.310772476918482],"eccentricity":[0.11,0.11],"host_mass_solar":[0.44,0.44],"host_radius_solar":[1.28,1.28],"host_temperature_k":[45,45],"semi_major_axis_km":[8975872.241999999,8975872.241999999],"orbital_period_days":[0.7,0.7],"argument_of_periastron_deg":[20,21]},"host_mass_solar":0.81,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":9.83,"planets_in_system":1,"discovery_facility":"McDonald Observatory","host_spectral_type":"K0","host_temperature_k":4639,"orbital_period_days":148.60001,"periastron_epoch_bjd":2453587.5,"equilibrium_temperature_k":897.99,"argument_of_periastron_deg":270},"designations":[{"catalog":"Exoplanet","designation":"HD 216536 b"},{"catalog":"Host star","designation":"HD 216536"}],"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."}