{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.677","julian_year":2026.677,"time":"2026-09-05T08:43:00.307Z","years_from_j2000":26.677,"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":"bet-cnc-b","name":"β Cnc b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":290.433121978184,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":124.1286379,"dec_deg":9.1853306,"epoch_ra_deg":124.492871,"epoch_dec_deg":9.102933,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"β Cnc","semi_major_axis_km":254316380.18999997,"periapsis_km":null,"mass_kg":1.4805004144254829e+28,"mass_msun":0.00744565,"constellation":"Cancer","discovered":"2014","featured":false,"url":"https://spacecatalog.org/object/bet-cnc-b","radius_km":80364.06,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"β Cnc","host_v_mag":3.51012,"eccentricity":0.08,"uncertainties":{"mass_kg":[1.518722288779348e+27,1.518722288779348e+27],"distance_ly":[25.086383023358863,25.086383023358863],"eccentricity":[0.02,0.02],"host_mass_solar":[0.1,0.1],"host_radius_solar":[1.3,1.3],"host_temperature_k":[17.5,17.5],"semi_major_axis_km":[14959787.07,14959787.07],"orbital_period_days":[4,4],"argument_of_periastron_deg":[5.9,5.9]},"host_mass_solar":1.7,"stars_in_system":2,"discovery_method":"Radial Velocity","host_radius_solar":47.2,"planets_in_system":1,"discovery_facility":"Bohyunsan Optical Astronomical Observatory","host_spectral_type":"K4 III","host_temperature_k":4092.1,"orbital_period_days":605.2,"periastron_epoch_bjd":2453229.8,"equilibrium_temperature_k":1039.74,"argument_of_periastron_deg":58.9},"designations":[{"catalog":"Exoplanet","designation":"bet Cnc b"},{"catalog":"Host star","designation":"bet Cnc"}],"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."}