{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T17:10:14.216Z","years_from_j2000":26.686,"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-56640-b","name":"HIP 56640 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":398.9675274782292,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":174.2008941,"dec_deg":-37.0391349,"epoch_ra_deg":174.53234,"epoch_dec_deg":-37.187785,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HIP 56640","semi_major_axis_km":680670311.685,"periapsis_km":null,"mass_kg":1.2850303540352998e+28,"mass_msun":0.0064626,"constellation":"Centaurus","discovered":"2021","featured":false,"url":"https://spacecatalog.org/object/hip-56640-b","radius_km":81001.87,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HIP 56640","host_v_mag":7.94,"eccentricity":0.118,"uncertainties":{"mass_kg":[2.30242513949893e+27,3.528613630929827e+27],"distance_ly":[1.8949685545342791,1.9145379371972837],"eccentricity":[0.076,0.062],"host_mass_solar":[0.101,0.101],"inclination_deg":[43.671,49.211],"host_radius_solar":[0.05,0.05],"host_temperature_k":[55,55],"semi_major_axis_km":[22439680.604999997,33061129.4247],"orbital_period_days":[108.29793,183.35403],"argument_of_periastron_deg":[51.54,47.207]},"host_mass_solar":1.75,"inclination_deg":85.093,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":4.93,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"K1 III","host_temperature_k":4769,"orbital_period_days":2675.57603,"periastron_epoch_bjd":2454396.523,"equilibrium_temperature_k":239.37,"argument_of_periastron_deg":111.481},"designations":[{"catalog":"Exoplanet","designation":"HIP 56640 b"},{"catalog":"Host star","designation":"HIP 56640"}],"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."}