{"release":{"id":"DR1","released_on":"2026-08-21","doi":null,"url":"https://spacecatalog.org/releases#dr1"},"epoch":{"requested":"now","label":"J2026.674","julian_year":2026.674,"time":"2026-09-04T02:37:33.139Z","years_from_j2000":26.674,"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":"au-mic-c","name":"AU Mic c","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":31.709249197999508,"distance_method":"NASA Exoplanet Archive sy_dist (TICv8, 2019AJ....158..138S)","ra_deg":311.2911369,"dec_deg":-31.34245,"epoch_ra_deg":311.704203,"epoch_dec_deg":-31.245108,"epoch_moved_arcsec":null,"pm_ra_mas_yr":null,"pm_dec_mas_yr":null,"orbits":"AU Mic","semi_major_axis_km":17802146.6133,"periapsis_km":null,"mass_kg":8.635754736826335e+25,"mass_msun":0.0000434305,"constellation":"Microscopium","discovered":"2021","featured":false,"url":"https://spacecatalog.org/object/au-mic-c","radius_km":17794.899,"radius_kind":null,"data_quality":null,"description":null,"properties":{"host_star":"AU Mic","host_v_mag":8.81,"eccentricity":0.18,"uncertainties":{"mass_kg":[2.0424814107846515e+25,1.934982389164407e+25],"radius_km":[1084.277,1148.058],"distance_ly":[0.015084732469399382,0.015084732469399382],"eccentricity":[0.07,0.08],"host_mass_solar":[0.07,0.04],"inclination_deg":[0.38,0.43],"host_radius_solar":[0.052,0.052],"host_temperature_k":[110,120],"semi_major_axis_km":[1645576.5776999998,1645576.5776999998],"orbital_period_days":[0.000024,0.000022],"argument_of_periastron_deg":[49,60.7]},"host_mass_solar":0.635,"inclination_deg":89.46,"stars_in_system":1,"discovery_method":"Transit","host_radius_solar":0.862,"planets_in_system":4,"discovery_facility":"Transiting Exoplanet Survey Satellite (TESS)","host_spectral_type":"M1 V","host_temperature_k":3540,"orbital_period_days":18.859023,"periastron_epoch_bjd":2458324,"transit_midpoint_bjd":2458342.223325,"equilibrium_temperature_k":424.7,"argument_of_periastron_deg":72.8},"designations":[{"catalog":"Exoplanet","designation":"AU Mic c"}],"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."}