{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.678","julian_year":2026.678,"time":"2026-09-05T15:03:24.371Z","years_from_j2000":26.678,"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-4208-b","name":"HD 4208 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":111.52493332733009,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":11.1125532,"dec_deg":-26.5150392,"epoch_ra_deg":11.443285,"epoch_dec_deg":-26.367942,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 4208","semi_major_axis_km":248631661.10339996,"periapsis_km":null,"mass_kg":1.5374886318703086e+27,"mass_msun":0.000773225,"constellation":"Sculptor","discovered":"2001","featured":false,"url":"https://spacecatalog.org/object/hd-4208-b","radius_km":88655.59000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 4208","host_v_mag":7.783,"eccentricity":0.042,"uncertainties":{"mass_kg":[2.847201170130201e+25,2.6573877587881877e+25],"distance_ly":[0.22113402409195204,0.22211249322510224],"eccentricity":[0.029,0.039],"host_mass_solar":[0.024,0.024],"host_radius_solar":[0.028,0.028],"host_temperature_k":[33,33],"semi_major_axis_km":[2243968.0604999997,2243968.0604999997],"orbital_period_days":[1.89,2.15],"argument_of_periastron_deg":[67.497,57.556]},"host_mass_solar":0.883,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":0.846,"planets_in_system":1,"discovery_facility":"W. M. Keck Observatory","host_spectral_type":"G7 V Fe-1 CH-0.5","host_temperature_k":5717,"orbital_period_days":832.97,"periastron_epoch_bjd":2456505.5,"transit_midpoint_bjd":2452114,"equilibrium_temperature_k":196.68,"argument_of_periastron_deg":217.634},"designations":[{"catalog":"Exoplanet","designation":"HD 4208 b"},{"catalog":"Host star","designation":"HD 4208"}],"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."}