{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.669","julian_year":2026.669,"time":"2026-09-02T12:10:02.662Z","years_from_j2000":26.669,"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":"xi-aql-b","name":"ξ Aql b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":183.253570071174,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":298.5624491,"dec_deg":8.4611051,"epoch_ra_deg":298.886714,"epoch_dec_deg":8.53092,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"ξ Aql","semi_major_axis_km":93498669.1875,"periapsis_km":null,"mass_kg":3.684259848145711e+27,"mass_msun":0.00185287,"constellation":"Aquila","discovered":"2007","featured":false,"url":"https://spacecatalog.org/object/xi-aql-b","radius_km":85466.54000000001,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"ξ Aql","host_v_mag":4.70964,"eccentricity":0.059,"uncertainties":{"mass_kg":[3.3976430333853645e+26,1.727293385957781e+26],"distance_ly":[1.8256603242694711,1.8256603242694711],"eccentricity":[0.037,0.087],"host_mass_solar":[0.28,0.21],"host_radius_solar":[1.05,0.44],"semi_major_axis_km":[149597.8707,0],"orbital_period_days":[0.18,0.11],"argument_of_periastron_deg":[2.3,106.4]},"host_mass_solar":1.74,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":10.86,"planets_in_system":1,"discovery_facility":"Okayama Astrophysical Observatory","host_spectral_type":"K0 III","host_temperature_k":4841,"orbital_period_days":136.97,"periastron_epoch_bjd":2453001,"equilibrium_temperature_k":973.07,"argument_of_periastron_deg":0},"designations":[{"catalog":"Exoplanet","designation":"xi Aql b"},{"catalog":"Host star","designation":"xi Aql"}],"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":"2026-09-01T22:58:55.274Z","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."}