{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T17:40:29.574Z","years_from_j2000":26.678,"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-53-b","name":"HAT-P-53 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2174.8172497427995,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":21.8711012,"dec_deg":38.9681137,"epoch_ra_deg":22.259099,"epoch_dec_deg":39.107561,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-53","semi_major_axis_km":4725796.735413,"periapsis_km":null,"mass_kg":2.816831024315479e+27,"mass_msun":0.00141662,"constellation":"Andromeda","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/hat-p-53-b","radius_km":94226.61798220001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-53","host_v_mag":13.78,"uncertainties":{"mass_kg":[1.0629551035152751e+26,1.0629551035152751e+26],"radius_km":[6505.7831839,6505.7831839],"distance_ly":[47.68080085841072,49.823648260009726],"host_mass_solar":[0.043,0.043],"inclination_deg":[1.5,1.5],"host_radius_solar":[0.062,0.081],"host_temperature_k":[50,50],"semi_major_axis_km":[62831.105694,62831.105694],"orbital_period_days":[0.0000039,0.0000039]},"host_mass_solar":1.093,"inclination_deg":86.2,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.209,"planets_in_system":1,"discovery_facility":"HATNet","host_temperature_k":5956,"orbital_period_days":1.9616241,"transit_midpoint_bjd":2455829.44781,"eccentricity_upper_limit":0.134,"equilibrium_temperature_k":1778},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-53 b"},{"catalog":"Host star","designation":"HAT-P-53"}],"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."}