{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.683","julian_year":2026.683,"time":"2026-09-07T09:18:35.630Z","years_from_j2000":26.683,"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-188641-b","name":"HD 188641 b","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":209.84868726657498,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":299.4048303,"dec_deg":-37.7448845,"epoch_ra_deg":299.850483,"epoch_dec_deg":-37.672939,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 188641","semi_major_axis_km":1799213590.9088998,"periapsis_km":null,"mass_kg":5.573842887182624e+28,"mass_msun":0.0280317,"constellation":"Sagittarius","discovered":"2022","featured":false,"url":"https://spacecatalog.org/object/hd-188641-b","radius_km":75899.39,"radius_kind":null,"data_quality":"The published mass and radius imply a density no material has. One of the two is likely an upper limit rather than a measurement.","description":null,"properties":{"host_star":"HD 188641","host_v_mag":7.34,"eccentricity":0.034,"uncertainties":{"mass_kg":[7.045838514273058e+27,1.135837760495616e+28],"distance_ly":[0.5818629778466703,0.5847983852461209],"eccentricity":[0.088,0.059],"host_mass_solar":[0.133,0.133],"inclination_deg":[4.827,4.35],"host_radius_solar":[0.080034,0.072619],"host_temperature_k":[116.19,85.35],"semi_major_axis_km":[234419863.38689998,283787160.7179],"orbital_period_days":[2616.26788,3328.20988],"argument_of_periastron_deg":[87.757,92.249]},"host_mass_solar":1.07,"inclination_deg":49.245,"stars_in_system":1,"discovery_method":"Radial Velocity","host_radius_solar":1.94492,"planets_in_system":1,"discovery_facility":"Multiple Observatories","host_temperature_k":5897.32,"orbital_period_days":14583.81038,"periastron_epoch_bjd":2446031.507,"equilibrium_temperature_k":114.36,"argument_of_periastron_deg":250.078},"designations":[{"catalog":"Exoplanet","designation":"HD 188641 b"},{"catalog":"Host star","designation":"HD 188641"}],"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."}