{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T10:17:55.557Z","years_from_j2000":26.686,"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-20-b","name":"HAT-P-20 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":231.69301066415392,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":111.9164295,"dec_deg":24.3361185,"epoch_ra_deg":112.323715,"epoch_dec_deg":24.281931,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-20","semi_major_axis_km":5400483.13227,"periapsis_km":null,"mass_kg":1.3753299410568898e+28,"mass_msun":0.00691673,"constellation":"Gemini","discovered":"2010","featured":false,"url":"https://spacecatalog.org/object/hat-p-20-b","radius_km":61982.3758,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-20","host_v_mag":11.231,"eccentricity":0.015,"uncertainties":{"mass_kg":[3.549378807185773e+26,3.549378807185773e+26],"radius_km":[2359.897,2359.897],"distance_ly":[0.6467680970123022,0.6503558171671864],"eccentricity":[0.005,0.005],"host_mass_solar":[0.028,0.028],"inclination_deg":[0.2,0.2],"host_radius_solar":[0.021,0.021],"host_temperature_k":[80,80],"semi_major_axis_km":[74798.93535,74798.93535],"orbital_period_days":[0.000004,0.000004],"argument_of_periastron_deg":[130,130]},"host_mass_solar":0.756,"inclination_deg":86.8,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.694,"planets_in_system":1,"discovery_facility":"HATNet","host_spectral_type":"K3","host_temperature_k":4595,"orbital_period_days":2.875317,"periastron_epoch_bjd":2455942.681,"transit_midpoint_bjd":2455080.92661,"equilibrium_temperature_k":970,"argument_of_periastron_deg":317},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-20 b"},{"catalog":"Host star","designation":"HAT-P-20"}],"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."}