{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.685","julian_year":2026.685,"time":"2026-09-08T04:48:29.998Z","years_from_j2000":26.685,"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":"bd-48-740-b","name":"BD+48 740 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":2174.122536658263,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":40.7425426,"dec_deg":48.9300579,"epoch_ra_deg":41.197601,"epoch_dec_deg":49.044522,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"BD+48 740","semi_major_axis_km":254316380.18999997,"periapsis_km":null,"mass_kg":3.226827992814228e+27,"mass_msun":0.00162282,"constellation":"Perseus","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/bd-48-740-b","radius_km":86104.35,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"BD+48 740","host_v_mag":8.69,"eccentricity":0.76,"uncertainties":{"mass_kg":[1.328693879394094e+27,1.328693879394094e+27],"distance_ly":[70.23288359563495,70.23288359563495],"eccentricity":[0.09,0.05],"host_mass_solar":[0.16,0.16],"host_radius_solar":[1.81,1.81],"host_temperature_k":[8,8],"semi_major_axis_km":[14959787.07,14959787.07],"orbital_period_days":[8,5],"argument_of_periastron_deg":[15,12]},"host_mass_solar":1.09,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":10.33,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_spectral_type":"K3 III","host_temperature_k":4534,"orbital_period_days":733,"periastron_epoch_bjd":2454774.5,"equilibrium_temperature_k":538.94,"argument_of_periastron_deg":100},"designations":[{"catalog":"Exoplanet","designation":"BD+48 740 b"},{"catalog":"Host star","designation":"BD+48 740"}],"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."}