{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T17:09:31.637Z","years_from_j2000":26.686,"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-208527-b","name":"HD 208527 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":1018.2667343592273,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":329.0999413,"dec_deg":21.239922,"epoch_ra_deg":329.413645,"epoch_dec_deg":21.367314,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 208527","semi_major_axis_km":314155528.46999997,"periapsis_km":null,"mass_kg":1.8790828979218796e+28,"mass_msun":0.00945018,"constellation":"Pegasus","discovered":"2012","featured":false,"url":"https://spacecatalog.org/object/hd-208527-b","radius_km":79726.25,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 208527","host_v_mag":6.38984,"eccentricity":0.08,"uncertainties":{"mass_kg":[3.226762298967682e+27,3.226762298967682e+27],"distance_ly":[34.63454574974098,37.116595784165405],"eccentricity":[0.04,0.04],"host_mass_solar":[0.4,0.4],"host_radius_solar":[8.3,8.3],"host_temperature_k":[65,65],"semi_major_axis_km":[29919574.14,29919574.14],"orbital_period_days":[5.8,5.8],"argument_of_periastron_deg":[19.5,19.5]},"host_mass_solar":1.6,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":51.1,"planets_in_system":1,"discovery_facility":"Bohyunsan Optical Astronomical Observatory","host_spectral_type":"M1 III","host_temperature_k":4035,"orbital_period_days":875.5,"periastron_epoch_bjd":2450745.3,"equilibrium_temperature_k":959.79,"argument_of_periastron_deg":278},"designations":[{"catalog":"Exoplanet","designation":"HD 208527 b"},{"catalog":"Host star","designation":"HD 208527"}],"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."}