{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.680","julian_year":2026.68,"time":"2026-09-06T07:33:56.872Z","years_from_j2000":26.68,"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-74156-b","name":"HD 74156 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":187.87585825617572,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":130.6047813,"dec_deg":4.5772338,"epoch_ra_deg":130.958067,"epoch_dec_deg":4.481284,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 74156","semi_major_axis_km":41887403.796000004,"periapsis_km":null,"mass_kg":3.179358704622368e+27,"mass_msun":0.00159895,"constellation":"Hydra","discovered":"2003","featured":false,"url":"https://spacecatalog.org/object/hd-74156-b","radius_km":86104.35,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 74156","host_v_mag":7.61,"eccentricity":0.636,"uncertainties":{"mass_kg":[2.714318177592389e+26,2.5814494555496967e+26],"distance_ly":[0.5231548298576564,0.5260902372571071],"eccentricity":[0.005,0.008],"host_mass_solar":[0.136,0.136],"host_radius_solar":[0.034482,0.034482],"host_temperature_k":[44,44],"semi_major_axis_km":[1795174.4483999999,1645576.5776999998],"orbital_period_days":[0.00113,0.001],"argument_of_periastron_deg":[0.794,0.915]},"host_mass_solar":1.1,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.510576,"planets_in_system":2,"discovery_facility":"Haute-Provence Observatory","host_spectral_type":"G0","host_temperature_k":6068,"orbital_period_days":51.63564,"periastron_epoch_bjd":2450793.515,"transit_midpoint_bjd":2455231.464,"equilibrium_temperature_k":679.63,"argument_of_periastron_deg":174.4},"designations":[{"catalog":"Exoplanet","designation":"HD 74156 b"},{"catalog":"Host star","designation":"HD 74156"}],"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."}