{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.679","julian_year":2026.679,"time":"2026-09-05T23:21:21.536Z","years_from_j2000":26.679,"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-219666-b","name":"HD 219666 b","class":"neptune_like_planet","category":"exoplanet","object_type":"Neptune-like planet","mag":null,"mag_band":null,"abs_mag":null,"abs_mag_band":null,"distance_ly":307.1476578670339,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":349.5592665,"dec_deg":-56.9039857,"epoch_ra_deg":349.947591,"epoch_dec_deg":-56.757232,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 219666","semi_major_axis_km":9508440.661692,"periapsis_km":null,"mass_kg":1.0511015447312827e+26,"mass_msun":0.0000528614,"constellation":"Tucana","discovered":"2018","featured":false,"url":"https://spacecatalog.org/object/hd-219666-b","radius_km":31239.9338,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 219666","host_v_mag":9.809,"eccentricity":0.05,"uncertainties":{"mass_kg":[7.166601441349655e+24,7.166601441349655e+24],"radius_km":[382.68600000000004,382.68600000000004],"distance_ly":[0.8173478825581589,0.82126175909076],"eccentricity":[0.04,0.04],"host_mass_solar":[0.1,0.1],"inclination_deg":[0.23,0.23],"host_radius_solar":[0.008,0.008],"host_temperature_k":[63,63],"semi_major_axis_km":[396434.357355,396434.357355],"orbital_period_days":[0.000004,0.000004],"argument_of_periastron_deg":[48,48]},"host_mass_solar":1.02,"inclination_deg":86.42,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":1.059,"planets_in_system":1,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"G5 V","host_temperature_k":5540,"orbital_period_days":6.034468,"transit_midpoint_bjd":2459083.5107,"equilibrium_temperature_k":1076,"argument_of_periastron_deg":0},"designations":[{"catalog":"Exoplanet","designation":"HD 219666 b"},{"catalog":"Host star","designation":"HD 219666"}],"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."}