{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.681","julian_year":2026.681,"time":"2026-09-06T20:41:48.372Z","years_from_j2000":26.681,"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-191806-b","name":"HD 191806 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":214.17645624249846,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":302.368758,"dec_deg":52.2767265,"epoch_ra_deg":302.548009,"epoch_dec_deg":52.35506,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 191806","semi_major_axis_km":411244546.5543,"periapsis_km":null,"mass_kg":1.7717095014141175e+28,"mass_msun":0.00891018,"constellation":"Cygnus","discovered":"2016","featured":false,"url":"https://spacecatalog.org/object/hd-191806-b","radius_km":79726.25,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 191806","host_v_mag":8.09,"eccentricity":0.213,"uncertainties":{"mass_kg":[1.6172021589688372e+27,1.7443765071585097e+27],"distance_ly":[0.3652951430427526,0.36692592493133636],"eccentricity":[0.028,0.029],"host_mass_solar":[0.129,0.129],"inclination_deg":[4.851,5.83],"host_radius_solar":[0.022074,0.023907],"host_temperature_k":[30,30],"semi_major_axis_km":[17652548.742599998,15857374.294199998],"orbital_period_days":[11.31279,9.94172],"argument_of_periastron_deg":[5.388,5.623]},"host_mass_solar":1.07,"inclination_deg":66.519,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.40223,"planets_in_system":1,"discovery_facility":"Haute-Provence Observatory","host_spectral_type":"K0","host_temperature_k":6010,"orbital_period_days":1603.38923,"periastron_epoch_bjd":2451758.874,"equilibrium_temperature_k":206.98,"argument_of_periastron_deg":346.184},"designations":[{"catalog":"Exoplanet","designation":"HD 191806 b"},{"catalog":"Host star","designation":"HD 191806"}],"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."}