{"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":"2026-09-07T08:09:39.690Z","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-158996-b","name":"HD 158996 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":925.1719194675372,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":259.9051092,"dec_deg":80.1364033,"epoch_ra_deg":259.406715,"epoch_dec_deg":80.107283,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 158996","semi_major_axis_km":314155528.46999997,"periapsis_km":null,"mass_kg":2.6573877587881876e+28,"mass_msun":0.0133644,"constellation":"Ursa Minor","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/hd-158996-b","radius_km":78450.63,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 158996","host_v_mag":5.72291,"eccentricity":0.13,"uncertainties":{"mass_kg":[4.365708460866308e+27,4.365708460866308e+27],"distance_ly":[14.915131152986678,14.915131152986678],"eccentricity":[0.05,0.05],"host_mass_solar":[0.3,0.3],"host_radius_solar":[4.3,4.3],"host_temperature_k":[30,30],"semi_major_axis_km":[29919574.14,29919574.14],"orbital_period_days":[14,14],"argument_of_periastron_deg":[12,12]},"host_mass_solar":1.8,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":50.3,"planets_in_system":1,"discovery_facility":"Bohyunsan Optical Astronomical Observatory","host_spectral_type":"K5 III","host_temperature_k":4069,"orbital_period_days":820.2,"periastron_epoch_bjd":2454993,"equilibrium_temperature_k":960.27,"argument_of_periastron_deg":168},"designations":[{"catalog":"Exoplanet","designation":"HD 158996 b"},{"catalog":"Host star","designation":"HD 158996"}],"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."}