{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.687","julian_year":2026.687,"time":"2026-09-08T20:34:36.701Z","years_from_j2000":26.687,"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":"hu-aqr-ab-c","name":"HU Aqr AB c","class":"gas_giant","category":"exoplanet","object_type":"Gas giant","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":626.8662915617115,"distance_method":"NASA Exoplanet Archive sy_dist (Gaia DR2, 2018A&A...616A...1G)","ra_deg":316.9921976,"dec_deg":-5.2948694,"epoch_ra_deg":317.345988,"epoch_dec_deg":-5.186733,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HU Aqr","semi_major_axis_km":807828501.78,"periapsis_km":null,"mass_kg":8.541603510390603e+27,"mass_msun":0.0042957,"constellation":"Aquarius","discovered":"2011","featured":false,"url":"https://spacecatalog.org/object/hu-aqr-ab-c","radius_km":82277.49,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HU Aqr","host_v_mag":16.183,"eccentricity":0.51,"uncertainties":{"mass_kg":[9.49067056710067e+26,9.49067056710067e+26],"distance_ly":[7.600619883776356,7.600619883776356],"eccentricity":[0.15,0.15],"host_temperature_k":[350.8,919.8],"semi_major_axis_km":[134638083.63,134638083.63],"orbital_period_days":[515,515],"argument_of_periastron_deg":[0.5,0.5]},"host_mass_solar":0.88,"inclination_deg":90,"stars_in_system":2,"discovery_method":"Eclipse Timing Variations","planets_in_system":2,"discovery_facility":"Yunnan Astronomical Observatory","host_temperature_k":5952,"orbital_period_days":4368,"periastron_epoch_bjd":2450299.4,"argument_of_periastron_deg":3.4},"designations":[{"catalog":"Exoplanet","designation":"HU Aqr AB c"},{"catalog":"Host star","designation":"HU Aqr"}],"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."}