{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T23:31:18.925Z","years_from_j2000":26.679,"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-159243-c","name":"HD 159243 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":239.09056346714732,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":263.3395365,"dec_deg":5.7008254,"epoch_ra_deg":263.668933,"epoch_dec_deg":5.681632,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 159243","semi_major_axis_km":119678296.56,"periapsis_km":null,"mass_kg":3.6065921753592136e+27,"mass_msun":0.00181381,"constellation":"Ophiuchus","discovered":"2013","featured":false,"url":"https://spacecatalog.org/object/hd-159243-c","radius_km":85466.54000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 159243","host_v_mag":8.65,"eccentricity":0.075,"uncertainties":{"mass_kg":[2.467699762971398e+26,2.467699762971398e+26],"distance_ly":[0.7645105493680465,0.7690767386560811],"eccentricity":[0.05,0.05],"host_mass_solar":[0.03,0.03],"host_radius_solar":[0.05,0.05],"host_temperature_k":[65,65],"semi_major_axis_km":[2991957.414,2991957.414],"orbital_period_days":[4.9,4.9],"argument_of_periastron_deg":[97,97]},"host_mass_solar":1.125,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.12,"planets_in_system":2,"discovery_facility":"Haute-Provence Observatory","host_spectral_type":"G0 V","host_temperature_k":6123,"orbital_period_days":248.4,"equilibrium_temperature_k":349.35,"argument_of_periastron_deg":69},"designations":[{"catalog":"Exoplanet","designation":"HD 159243 c"},{"catalog":"Host star","designation":"HD 159243"}],"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."}