{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.673","julian_year":2026.673,"time":"2026-09-03T23:37:25.857Z","years_from_j2000":26.673,"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":"gam-cep-b","name":"γ Cep b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":45.99587701112602,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":354.8358233,"dec_deg":77.6331009,"epoch_ra_deg":355.109291,"epoch_dec_deg":77.781825,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"γ Cep","semi_major_axis_km":318643464.59099996,"periapsis_km":null,"mass_kg":1.2527622358394355e+28,"mass_msun":0.00630032,"constellation":"Cepheus","discovered":"2003","featured":false,"url":"https://spacecatalog.org/object/gam-cep-b","radius_km":81001.87,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"γ Cep","host_v_mag":3.23006,"eccentricity":0.15,"uncertainties":{"mass_kg":[5.314748879318818e+27,4.3656865794404574e+27],"distance_ly":[0.32266585216241883,0.32266585216241883],"eccentricity":[0.05,0.07],"host_mass_solar":[0.07,0.05],"host_radius_solar":[0.08,0.07],"host_temperature_k":[31,33],"semi_major_axis_km":[7479893.535,7479893.535],"orbital_period_days":[3,3],"argument_of_periastron_deg":[7,6]},"host_mass_solar":1.27,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":4.74,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"K1 III-IV","host_temperature_k":4775,"orbital_period_days":913,"periastron_epoch_bjd":2453121.925,"transit_midpoint_bjd":2453117,"equilibrium_temperature_k":343.48,"argument_of_periastron_deg":49},"designations":[{"catalog":"Exoplanet","designation":"gam Cep b"},{"catalog":"Host star","designation":"gam Cep"}],"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."}