{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T14:53:57.107Z","years_from_j2000":26.678,"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":"hip-39017-b","name":"HIP 39017 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":216.31245436016545,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":119.7665756,"dec_deg":-4.3326006,"epoch_ra_deg":120.100747,"epoch_dec_deg":-4.405236,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 39017","semi_major_axis_km":3306112942.47,"periapsis_km":null,"mass_kg":4.479574055425861e+28,"mass_msun":0.0225284,"constellation":"Monoceros","discovered":"2024","featured":false,"url":"https://spacecatalog.org/object/hip-39017-b","radius_km":76537.20000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 39017","host_v_mag":6.96076,"eccentricity":0.55,"uncertainties":{"mass_kg":[1.4046122038199734e+28,1.7272933857786157e+28],"distance_ly":[0.6637282286535728,0.6676421051861737],"eccentricity":[0.39,0.35],"host_mass_solar":[0.26,0.28],"inclination_deg":[20,14],"host_radius_solar":[0.074338,0.040637],"host_temperature_k":[111.62,142.41],"semi_major_axis_km":[1196782965.6,1196782965.6],"orbital_period_days":[9500,19000],"argument_of_periastron_deg":[115,131]},"host_mass_solar":1.52,"inclination_deg":84,"stars_in_system":1,"discovery_method":"Imaging","host_radius_solar":1.51987,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"A9/F0","host_temperature_k":7201,"orbital_period_days":31000,"periastron_epoch_bjd":2469682,"equilibrium_temperature_k":91.06,"argument_of_periastron_deg":174},"designations":[{"catalog":"Exoplanet","designation":"HIP 39017 b"},{"catalog":"Host star","designation":"HIP 39017"}],"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."}