{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T23:51:40.348Z","years_from_j2000":26.679,"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":"hat-p-16-b","name":"HAT-P-16 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":739.1910297658958,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":9.5730343,"dec_deg":42.4630961,"epoch_ra_deg":9.938393,"epoch_dec_deg":42.610868,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-16","semi_major_axis_km":6178392.05991,"periapsis_km":null,"mass_kg":8.012024092746386e+27,"mass_msun":0.00402936,"constellation":"Andromeda","discovered":"2010","featured":false,"url":"https://spacecatalog.org/object/hat-p-16-b","radius_km":93654.519760632,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-16","host_v_mag":10.911,"eccentricity":0.0462,"uncertainties":{"mass_kg":[1.7462833843465232e+26,1.7462833843465232e+26],"radius_km":[4289.519975404,4289.519975404],"distance_ly":[14.041032060705803,14.5824516477156],"eccentricity":[0.0024,0.0027],"host_mass_solar":[0.039,0.039],"inclination_deg":[1,1],"host_radius_solar":[0.025,0.025],"host_temperature_k":[72,72],"semi_major_axis_km":[59839.14828,59839.14828],"orbital_period_days":[9e-8,9e-8],"argument_of_periastron_deg":[5.4,5.1]},"host_mass_solar":1.218,"inclination_deg":88.4,"stars_in_system":3,"discovery_method":"Transit","host_radius_solar":1.158,"planets_in_system":1,"discovery_facility":"HATNet","host_spectral_type":"F8","host_temperature_k":6140,"orbital_period_days":2.77596727,"transit_midpoint_bjd":2455027.60356,"equilibrium_temperature_k":1566,"argument_of_periastron_deg":213},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-16 b"},{"catalog":"Host star","designation":"HAT-P-16"}],"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."}