{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.689","julian_year":2026.689,"time":"2026-09-09T18:02:17.352Z","years_from_j2000":26.689,"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-38-b","name":"HATS-38 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1120.4286965514427,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":154.2710615,"dec_deg":-25.2762982,"epoch_ra_deg":154.583806,"epoch_dec_deg":-25.410247,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HATS-38","semi_major_axis_km":7533748.768452,"periapsis_km":null,"mass_kg":1.4046192439308991e+26,"mass_msun":0.0000706403,"constellation":"Hydra","discovered":"2020","featured":false,"url":"https://spacecatalog.org/object/hats-38-b","radius_km":43896.1634606,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HATS-38","host_v_mag":11.967,"eccentricity":0,"uncertainties":{"mass_kg":[2.0879475247621475e+25,2.0879475247621475e+25],"radius_km":[1215.3660893,1215.3660893],"distance_ly":[16.22954135518515,16.705729666651596],"host_mass_solar":[0.012,0.016],"inclination_deg":[0.18,0.18],"host_radius_solar":[0.016,0.016],"host_temperature_k":[25,25],"semi_major_axis_km":[34407.510260999996,44879.361209999995],"orbital_period_days":[0.00001,0.00001]},"host_mass_solar":0.89,"inclination_deg":87.21,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.105,"planets_in_system":1,"discovery_facility":"HATSouth","host_temperature_k":5732,"orbital_period_days":4.375021,"transit_midpoint_bjd":2457725.16042,"equilibrium_temperature_k":1294},"designations":[{"catalog":"Exoplanet","designation":"HATS-38 b"},{"catalog":"Host star","designation":"HATS-38"}],"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":"2026-09-09T11:17:28.634Z","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."}