{"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":"2026-09-06T17:21:09.912Z","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":"hd-56957-b","name":"HD 56957 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":200.56171056746845,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":109.3253986,"dec_deg":-40.6560651,"epoch_ra_deg":109.547733,"epoch_dec_deg":-40.703671,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 56957","semi_major_axis_km":961315917.1182,"periapsis_km":null,"mass_kg":1.1233101381384161e+28,"mass_msun":0.00564929,"constellation":"Puppis","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hd-56957-b","radius_km":81639.68000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 56957","host_v_mag":7.57,"eccentricity":0.273,"uncertainties":{"mass_kg":[7.641849638608613e+27,5.464700722681682e+27],"distance_ly":[0.3059346822983053,0.3072393078091723],"eccentricity":[0.136,0.178],"host_mass_solar":[0.131,0.131],"inclination_deg":[23.844,3.344],"host_radius_solar":[0.093866,0.057401],"host_temperature_k":[67.71,145.26],"semi_major_axis_km":[129701353.89689998,233971069.7748],"orbital_period_days":[959.68304,2325.96289],"argument_of_periastron_deg":[74.179,92.883]},"host_mass_solar":1.03,"inclination_deg":170.006,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.77793,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_temperature_k":5743,"orbital_period_days":5859.08992,"periastron_epoch_bjd":2448235.744,"equilibrium_temperature_k":145.67,"argument_of_periastron_deg":38.255},"designations":[{"catalog":"Exoplanet","designation":"HD 56957 b"},{"catalog":"Host star","designation":"HD 56957"}],"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."}