{"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":"2026-09-06T20:41:54.398Z","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-204313-c","name":"HD 204313 c","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":155.88480994782893,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":322.0510568,"dec_deg":-21.7274194,"epoch_ra_deg":322.432391,"epoch_dec_deg":-21.610577,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 204313","semi_major_axis_km":31565150.717699997,"periapsis_km":null,"mass_kg":1.0249872839880724e+26,"mass_msun":0.0000515481,"constellation":"Capricornus","discovered":"2015","featured":false,"url":"https://spacecatalog.org/object/hd-204313-c","radius_km":27489.611,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 204313","host_v_mag":7.99,"eccentricity":0.059,"uncertainties":{"mass_kg":[9.490623028644443e+24,9.490623028644443e+24],"distance_ly":[0.471622122178411,0.4745575295778616],"eccentricity":[0.041,0.051],"host_mass_solar":[0.132,0.132],"host_radius_solar":[0.02,0.02],"host_temperature_k":[17,17],"semi_major_axis_km":[1495978.707,1346380.8362999998],"orbital_period_days":[0.01156,0.0105],"argument_of_periastron_deg":[126.675,65.124]},"host_mass_solar":1.03,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.1,"planets_in_system":3,"discovery_facility":"La Silla Observatory","host_spectral_type":"G5 V","host_temperature_k":5767,"orbital_period_days":34.95875,"periastron_epoch_bjd":2449883.77,"equilibrium_temperature_k":634.95,"argument_of_periastron_deg":309.05},"designations":[{"catalog":"Exoplanet","designation":"HD 204313 c"}],"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."}