{"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":"2026-09-05T13:56:10.234Z","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":"hd-147018-c","name":"HD 147018 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":131.85067263025982,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":245.7490012,"dec_deg":-61.6901291,"epoch_ra_deg":246.345462,"epoch_dec_deg":-61.75293,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 147018","semi_major_axis_km":287527107.48539996,"periapsis_km":null,"mass_kg":1.242210916500607e+28,"mass_msun":0.00624726,"constellation":"Triangulum Australe","discovered":"2009","featured":false,"url":"https://spacecatalog.org/object/hd-147018-c","radius_km":81001.87,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 147018","host_v_mag":8.3,"eccentricity":0.133,"uncertainties":{"mass_kg":[5.972167867791379e+26,5.972167867791379e+26],"distance_ly":[0.23254949731203806,0.23352796644518828],"eccentricity":[0.011,0.011],"host_mass_solar":[0.031,0.031],"host_radius_solar":[0.014395,0.022735],"host_temperature_k":[55,55],"semi_major_axis_km":[5834316.9573,5834316.9573],"orbital_period_days":[18,18],"argument_of_periastron_deg":[6.9,6.9]},"host_mass_solar":0.927,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.937948,"planets_in_system":2,"discovery_facility":"La Silla Observatory","host_spectral_type":"G9 V","host_temperature_k":5441,"orbital_period_days":1008,"periastron_epoch_bjd":2455301,"equilibrium_temperature_k":183.28,"argument_of_periastron_deg":-133.1},"designations":[{"catalog":"Exoplanet","designation":"HD 147018 c"},{"catalog":"Host star","designation":"HD 147018"}],"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."}