{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T08:27:25.619Z","years_from_j2000":26.677,"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-66-b","name":"HAT-P-66 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":3051.0494047339394,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":150.5726262,"dec_deg":53.9508237,"epoch_ra_deg":151.019509,"epoch_dec_deg":53.821416,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-66","semi_major_axis_km":6526955.098641,"periapsis_km":null,"mass_kg":1.486239010807965e+27,"mass_msun":0.000747451,"constellation":"Ursa Major","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hat-p-66-b","radius_km":113672.47541100002,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-66","host_v_mag":13.014,"uncertainties":{"mass_kg":[1.0819364446494764e+26,1.0819364446494764e+26],"radius_km":[7149.21229,11438.739664],"distance_ly":[75.59326366340962,79.45495517557586],"host_mass_solar":[0.054,0.107],"inclination_deg":[1.8,1.8],"host_radius_solar":[0.095,0.151],"host_temperature_k":[50,50],"semi_major_axis_km":[95742.637248,181013.42354699998],"orbital_period_days":[0.0000057,0.0000057]},"host_mass_solar":1.255,"inclination_deg":86.2,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.881,"planets_in_system":1,"discovery_facility":"HATNet","host_spectral_type":"G0","host_temperature_k":6002,"orbital_period_days":2.972086,"transit_midpoint_bjd":2457258.79907,"eccentricity_upper_limit":0.09,"equilibrium_temperature_k":1896},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-66 b"},{"catalog":"Host star","designation":"HAT-P-66"}],"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."}