{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T15:18:22.414Z","years_from_j2000":26.683,"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-156098-c","name":"HD 156098 c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":157.36719068455153,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":259.264687,"dec_deg":-32.6630768,"epoch_ra_deg":259.703015,"epoch_dec_deg":-32.692642,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 156098","semi_major_axis_km":1258866081.9404998,"periapsis_km":null,"mass_kg":9.923395407552024e+27,"mass_msun":0.00499062,"constellation":"Scorpius","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hd-156098-c","radius_km":81639.68000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 156098","host_v_mag":5.53,"eccentricity":0.391,"uncertainties":{"mass_kg":[2.4428863598928716e+27,3.678565474352413e+27],"distance_ly":[1.2162371325057362,1.2348280460355905],"eccentricity":[0.051,0.04],"host_mass_solar":[0.2,0.2],"inclination_deg":[0,22.352],"host_radius_solar":[0.14133,0.119836],"host_temperature_k":[144.01,139.97],"semi_major_axis_km":[94097060.67029999,59240756.7972],"orbital_period_days":[516.56728,247.41756],"argument_of_periastron_deg":[3.639,5.962]},"host_mass_solar":1.29,"inclination_deg":23.462,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":2.75716,"planets_in_system":2,"discovery_facility":"Multiple Observatories","host_temperature_k":6419.19,"orbital_period_days":7841.5839,"periastron_epoch_bjd":2448310.896,"equilibrium_temperature_k":177.18,"argument_of_periastron_deg":219.678},"designations":[{"catalog":"Exoplanet","designation":"HD 156098 c"},{"catalog":"Host star","designation":"HD 156098"}],"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."}