{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T17:55:28.582Z","years_from_j2000":26.681,"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":"hats-31-b","name":"HATS-31 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2524.3655628693878,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":191.7028214,"dec_deg":-24.4273897,"epoch_ra_deg":192.060051,"epoch_dec_deg":-24.574221,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HATS-31","semi_major_axis_km":7150778.219459999,"periapsis_km":null,"mass_kg":1.670358019809718e+27,"mass_msun":0.000840047,"constellation":"Hydra","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hats-31-b","radius_km":117247.08155600002,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HATS-31","host_v_mag":13.315,"uncertainties":{"mass_kg":[2.277760936104161e+26,2.277760936104161e+26],"radius_km":[15728.267038000002,15728.267038000002],"distance_ly":[63.016673738652,66.26519126071076],"host_mass_solar":[0.096,0.096],"inclination_deg":[1.6,2.5],"host_radius_solar":[0.18,0.18],"host_temperature_k":[120,120],"semi_major_axis_km":[179517.44483999998,179517.44483999998],"orbital_period_days":[0.000012,0.000012]},"host_mass_solar":1.275,"inclination_deg":85,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.87,"planets_in_system":1,"discovery_facility":"HATSouth","host_temperature_k":6050,"orbital_period_days":3.37796,"transit_midpoint_bjd":2456960.1476,"eccentricity_upper_limit":0.233,"equilibrium_temperature_k":1823},"designations":[{"catalog":"Exoplanet","designation":"HATS-31 b"},{"catalog":"Host star","designation":"HATS-31"}],"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."}