{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.686","julian_year":2026.686,"time":"2026-09-08T11:14:27.932Z","years_from_j2000":26.686,"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-183579-b","name":"HD 183579 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":186.77377585587084,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":293.2866147,"dec_deg":-54.5327284,"epoch_ra_deg":293.824482,"epoch_dec_deg":-54.475064,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"HD 183579","semi_major_axis_km":19776838.50654,"periapsis_km":null,"mass_kg":1.2183222450294413e+26,"mass_msun":0.0000612712,"constellation":"Telescopium","discovered":"2021","featured":false,"url":"https://spacecatalog.org/object/hd-183579-b","radius_km":22259.569000000003,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"HD 183579","host_v_mag":8.67,"eccentricity":0.061,"uncertainties":{"mass_kg":[1.4930419669478448e+25,1.5527636456257586e+25],"radius_km":[408.19840000000005,446.46700000000004],"distance_ly":[0.6079554880640098,0.6115432082188939],"eccentricity":[0.042,0.061],"host_mass_solar":[0.049,0.049],"inclination_deg":[0.13,0.2],"host_radius_solar":[0.006,0.006],"host_temperature_k":[61,61],"semi_major_axis_km":[329115.31554,314155.52846999996],"orbital_period_days":[0.000028,0.000027],"argument_of_periastron_deg":[61,70]},"host_mass_solar":0.996,"inclination_deg":89.11,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.96,"planets_in_system":1,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"G2 V","host_temperature_k":5784,"orbital_period_days":17.471291,"transit_midpoint_bjd":2458661.06263,"equilibrium_temperature_k":752,"argument_of_periastron_deg":270},"designations":[{"catalog":"Exoplanet","designation":"HD 183579 b"},{"catalog":"Host star","designation":"HD 183579"}],"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."}