{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.675","julian_year":2026.675,"time":"2026-09-04T11:52:24.475Z","years_from_j2000":26.675,"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-3-b","name":"HAT-P-3 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":438.8564524729869,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":206.0940142,"dec_deg":48.028565,"epoch_ra_deg":206.3671,"epoch_dec_deg":47.893438,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HAT-P-3","semi_major_axis_km":5783453.6812619995,"periapsis_km":null,"mass_kg":1.2337871737230871e+27,"mass_msun":0.000620489,"constellation":"Ursa Major","discovered":"2007","featured":false,"url":"https://spacecatalog.org/object/hat-p-3-b","radius_km":67202.595526,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HAT-P-3","host_v_mag":11.856,"eccentricity":0,"uncertainties":{"mass_kg":[2.0879475247621476e+26,2.0879475247621476e+26],"radius_km":[5004.448603000001,5004.448603000001],"distance_ly":[1.555765921708866,1.5655506130403682],"host_mass_solar":[0.28,0.28],"inclination_deg":[0.69,0.69],"host_radius_solar":[0.06,0.06],"host_temperature_k":[80,80],"semi_major_axis_km":[61335.126986999996,61335.126986999996],"orbital_period_days":[0.000054,0.000054],"argument_of_periastron_deg":[1.7,1.7]},"host_mass_solar":1.06,"inclination_deg":87.24,"stars_in_system":2,"discovery_method":"Transit","host_radius_solar":0.87,"planets_in_system":1,"discovery_facility":"HATNet","host_spectral_type":"K1","host_temperature_k":5185,"orbital_period_days":2.8997,"periastron_epoch_bjd":2464187.008,"transit_midpoint_bjd":2455694.72623,"equilibrium_temperature_k":1189,"argument_of_periastron_deg":107.7},"designations":[{"catalog":"Exoplanet","designation":"HAT-P-3 b"},{"catalog":"Host star","designation":"HAT-P-3"}],"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."}