{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.684","julian_year":2026.684,"time":"2026-09-07T17:26:15.395Z","years_from_j2000":26.684,"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-38801-b","name":"HD 38801 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":298.22075780892663,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":86.9963141,"dec_deg":-8.3280256,"epoch_ra_deg":87.318739,"epoch_dec_deg":-8.318307,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 38801","semi_major_axis_km":242797344.14609998,"periapsis_km":null,"mass_kg":1.840810463194846e+28,"mass_msun":0.0092577,"constellation":"Orion","discovered":"2009","featured":false,"url":"https://spacecatalog.org/object/hd-38801-b","radius_km":79726.25,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 38801","host_v_mag":8.26,"eccentricity":0.017,"uncertainties":{"mass_kg":[1.1142047245776187e+27,1.0876308469897368e+27],"distance_ly":[1.1311103179216662,1.1311103179216662],"eccentricity":[0.011,0.013],"host_mass_solar":[0.108,0.108],"host_radius_solar":[0.286,0.286],"host_temperature_k":[59,59],"semi_major_axis_km":[7330295.664299999,7031099.9229],"orbital_period_days":[0.85,0.85],"argument_of_periastron_deg":[71.9,238.614]},"host_mass_solar":1.207,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":2.029,"planets_in_system":1,"discovery_facility":"Subaru Telescope","host_spectral_type":"K0","host_temperature_k":5338,"orbital_period_days":685.25,"periastron_epoch_bjd":2456752.9,"equilibrium_temperature_k":287.8,"argument_of_periastron_deg":97.115},"designations":[{"catalog":"Exoplanet","designation":"HD 38801 b"},{"catalog":"Host star","designation":"HD 38801"}],"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."}